This global warming GIF shows how hot Earth has gotten over the past 165 years


Photo: Spiraling global temperatures, 1850-2016.Ed Hawkins/Courtesy

THE YEAR 2016 IS ON PACE to be the warmest in recorded history. If trends hold, it will be hotter than the current record-holder, 2015, which took the crown from 2014.

You get the picture. Our planet is getting hotter. Fifteen of the 16 hottest years on record have come since 2001, NASA says. Climate scientists warn that effects for the Earth and humanity will be catastrophic if the global average temperature rises by 2 degrees Celsius above pre-industrial levels. Some say even 2 degrees is too much, and that humans need to hold the temperature increase below 1.5 degrees.

That’s why those two figures, 2 degrees and 1.5 degrees, were at the center of the Paris climate deal, which 195 nations agreed to in December. Those nations have pledged to keep the global temperature increase to “well below” 2 degrees, while aiming to hold it below a 1.5-degree increase, in recognition that the lower number “would significantly reduce risks and the impacts of climate change.”

That leaves us with the question: How far along are we already? Luckily, there’s a GIF for that.

Spiralling global temperatures from 1850-2016 (full animation) https://t.co/YETC5HkmTr pic.twitter.com/Ypci717AHq

— Ed Hawkins (@ed_hawkins) May 9, 2016

The graphic, created by Ed Hawkins, a climate researcher and professor in the University of Reading’s meteorology department, visualizes monthly global temperatures from 1850 to 2016 as a series of rings spiraling out toward those two key threshholds: 1.5 degrees and 2 degrees.

Each ring represents one year. Hawkins uses as a baseline the average annual temperature between 1850 and 1900, the same pre-industrial average used by the United Nations Intergovernmental Panel on Climate Change (IPCC) in its most recent assessment (Hawkins was a contributing writer). The animation’s data comes from the HadCRUT4 global temperature dataset, which is maintained by the Climatic Research Unit at the University of East Anglia and the Hadley Centre at the UK’s national weather service, the Met Office.

The resulting spiral is a simple, elegant illustration of a dark history and a potentially terrifying future.

“The animated spiral presents global temperature change in a visually appealing and straightforward way,” Hawkins explains. “The pace of change is immediately obvious, especially over the past few decades. The relationship between current global temperatures and the internationally discussed target limits are also clear without much complex interpretation needed.”

If the spiral doesn’t suit your brain, Hawkins provides other ways to visualize the same data.

Global temperature change by month (1850-2016) pic.twitter.com/mLJf6FM8mj

— Ed Hawkins (@ed_hawkins) May 4, 2016

And there’s always this time-lapse heat map from NASA. It’s pretty much the dataviz gold standard when it comes to animating our ongoing climate catastrophe.

by Timothy McGrath, PRI’s The World
This article is syndicated from GlobalPost.


Volcanic Ash

Volcanic ash is a mixture of rock, mineral, and glass particles expelled from a volcano during a volcanic eruption.

Earth Science, Geology, Geography

Shoveling volcanic ash

Removing volcanic ash can be a difficult and laborious process. Here, two Icelanders shovel volcanic ash from a hillside in Vestmannaeyjar, a volcanic archipelago off the southwest coast of Iceland.

Photograph by Robert S. Patton

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Volcanic ash is a mixture of rock, mineral, and glass particles expelled from a volcano during a volcanic eruption. The particles are very small—less than 2 millimeters in diameter. They tend to be pitted and full of holes, which gives them a low density. Along with water vapor and other hot gases, volcanic ash is part of the dark ash column that rises above a volcano when it erupts.

Due to their tiny size and low density, the particles that make up volcanic ash can travel long distances, carried by winds. When an ash column is moved about by wind, it is called an ash plume. Eventually the ash in the sky falls to the ground. It may create a thick layer of dust-like material on surfaces for miles around the original eruption.

Unlike the ash produced by burning wood and other organic materials, volcanic ash can be dangerous. Its particles are very hard and usually have jagged edges. As a result, it can cause eye, nose, and lung irritation, as well as breathing problems. While in the air, ash can cause problems for jet engines, forcing airlines to cancel flights through the affected area. An ashfall that leaves a thick layer of ash may cause roofs to collapse, clog gutters, and interfere with air conditioning units. Animals in an area coated by volcanic ash may have difficulty finding food, as the plants in the region may be covered in ash. Ash can also contaminate water supplies.

Removing volcanic ash can be a difficult and laborious process. Here, two Icelanders shovel volcanic ash from a hillside in Vestmannaeyjar, a volcanic archipelago off the southwest coast of Iceland.


Plate Tectonics and Volcanic Activity

A volcano is a feature in Earth's crust where molten rock is squeezed out onto the Earth's surface. Along with molten rock, volcanoes also release gases, ash, and solid rock.

Earth Science, Geology, Geography, Physical Geography

36 Images, 2 Links, 1 PDF, 1 Video

Links

Website

Photograph by J. Baylor Roberts, National Geographic

  • Vulcan (for whom volcanoes are named) is a Roman god.
  • Hephaestus is a Greek god from whom Vulcan developed.
  • Pele is a Hawaiian goddess.
  • Ruaumoko is a Maori god.
  • Xiahtecuhtli is an Aztec god.
  • Ayanju is a Yoruba orisha, or deity.
  • Kagu-Tsuchi is a Japanese kami, or spirit.
  • Avachinsky-Koryaksky, Russia
  • Colima, Mexico
  • Etna, Italy
  • Galeras, Colombia
  • Mauna Loa, USA
  • Merapi, Indonesia
  • Nyiragongo, Dem. Rep. of the Congo
  • Rainier, USA
  • Sakurajima, Japan
  • Santa Maria/Santiaguito, Guatemala
  • Santorini, Greece
  • Taal, Philippines
  • Teide, Spain (Canary Islands)
  • Ulawun, Papau New Guinea
  • Unzen, Japan
  • Vesuvius, Italy

chemical compound that reacts with a base to form a salt. Acids can corrode some natural materials. Acids have pH levels lower than 7.

volcano that has had a recorded eruption since the last glacial period, about 10,000 years ago.

the distance above sea level.

layers of gases surrounding a planet or other celestial body.

type of dark volcanic rock.

natural or artificial line separating two pieces of land.

line separating geographical areas.

large depression resulting from the collapse of the center of a volcano.

deep, narrow valley with steep sides.

impression formed when a liquid substance is poured into a form or mold, and then hardens into that shape.

to arrange by specific type or characteristic.

waterway between two relatively close land masses.

hill created by tiny bits of lava blown out of a volcano and fallen down around the volcanic vent. Also called a scoria cone.

edge of land along the sea or other large body of water.

strong, vertical support structure, such as a pillar.

items gathered closely together in one place.

hard building material made from mixing cement with rock and water.

to transmit, transport, or carry.

to distort or bend out of shape.

area where two or more tectonic plates bump into each other. Also called a collision zone.

to match or be similar to.

bowl-shaped depression formed by a volcanic eruption or impact of a meteorite.

rocky outermost layer of Earth or other planet.

(singular: datum) information collected during a scientific study.

remains of something broken or destroyed, waste, or garbage.

to put out of shape or distort.

having parts or molecules that are packed closely together.

indentation or dip in the landscape.

very destructive or damaging.

area where two or more tectonic plates are moving away from each other. Also called an extensional boundary.

varied or having many different types.

shape that is half of a sphere.

volcano that has erupted in the past but is unlikely to erupt soon.

to get rid of or throw out.

set of physical phenomena associated with the presence and flow of electric charge.

symbolic or representative.

to explode or suddenly eject material.

to leave or remove from a dangerous place.

limited to a few characteristics.

to be or place at the side of something.

overflow of a body of water onto land.

material that is able to flow and change shape.

person who studies the physical formations of the Earth.

study of the Earth's physical properties and processes.

natural hot spring that sometimes erupts with water or steam.

mass of ice that moves slowly over land.

relatively gentle volcanic eruption characterized by consistent, effusive flows of low-viscosity lava.

large peninsula in northeast Africa, including the countries of Somalia, Djibouti, Eritrea, and Ethiopia. Also called the Somali Peninsula.

intensely hot region deep within the Earth that rises to just underneath the surface. Some hot spots produce volcanoes.

small flow of water flowing naturally from an underground water source heated by hot or molten rock.

event or symbol representing a belief, nation, or community.

upcoming or about to happen.

to live in a specific place.

unit made up of governments or groups in different countries, usually for a specific purpose.

to explain or understand the meaning of something.

flow of mud and other wet material from a volcano.

specific natural feature on the Earth's surface.

the geographic features of a region.

the fall of rocks, soil, and other materials from a mountain, hill, or slope.

molten rock, or magma, that erupts from volcanoes or fissures in the Earth's surface.

feature formed as lava hardens over a volcanic vent.

phenomenon where lava is forcefully but not violently ejected from a volcano through a fissure or vent.

lava pooled in the center of a volcano's caldera or crater.

state of matter with no fixed shape and molecules that remain loosely bound with each other.

molten, or partially melted, rock beneath the Earth's surface.

underground reservoir that holds molten rock.

middle layer of the Earth, made of mostly solid rock.

process of determining length, width, mass (weight), volume, distance or some other quality or size.

underwater mountain range that runs from Iceland to Antarctica.

underwater mountain range.

to move from one place or activity to another.

process of becoming or making something milder and less severe.

solid material turned to liquid by heat.

speed, direction, or velocity at which something moves.

to observe and record behavior or data.

series or chain of mountains that are close together.

event in the physical environment that is destructive to human activity.

tall, tapering, four-sided stone structure.

ship, boat, submarine, or other vehicle able to travel the ocean.

equal distance apart, and never meeting.

volcanic activity driven by the direct interaction of magma and an external body of water.

paste-like material made of crushed stone (usually lime, gypsum, and sand), water, and fiber.

powerful, violent volcanic explosion characterized by pyroclastic flows and ejection of material high into the atmosphere.

single, upward flow of a fluid, such as water or smoke.

to know the outcome of a situation in advance.

to assemble or get ready for something.

force pressed on an object by another object or condition, such as gravity.

chance or likelihood of something happening.

very productive or abundant.

type of igneous rock with many pores.

hill created by tiny bits of lava blown out of a volcano and fallen down around the volcanic vent. Also called a cinder cone.

current of volcanic ash, lava, and gas that flows from a volcano.

energy, emitted as waves or particles, radiating outward from a source.

long, narrow elevation of earth.

break in the Earth's crust created by it spreading or splitting apart.

horseshoe-shaped string of volcanoes and earthquake sites around edges of the Pacific Ocean.

large stream of flowing fresh water.

depression in the earth caused by a river eroding the surrounding soil.

natural substance composed of solid mineral matter.

having an irregular or jagged surface.

type of rough, crusty volcanic rock.

base level for measuring elevations. Sea level is determined by measurements taken over a 19-year cycle.

large, gently sloping volcano made from fluid lava.

liquid waste, such as that from the coal mining and cleaning process, also called slurry.

precipitation made of ice crystals.

top layer of the Earth's surface where plants can grow.

level of Earth's atmosphere, extending from 10 kilometers (6 miles) to 50 kilometers (31 miles) above the surface of the Earth.

steep volcano made of hardened lava, rock, and ash. Also known as a composite volcano.

mildly violent explosion of a volcano.

to pull downward or beneath something.

area where one tectonic plate slides under another.

highest point of a mountain.

volcano capable of ejecting more than 1,000 cubic kilometers (240 cubic miles) of material.

sudden, strong movement forward.

phenomenon where a volcano erupts in an ocean, sea, or lake.

to temporarily stop an activity.

massive slab of solid rock made up of Earth's lithosphere (crust and upper mantle). Also called lithospheric plate.

degree of hotness or coldness measured by a thermometer with a numerical scale.

having to do with the Earth or dry land.

explanation that has not been proven as fact.

device that measures temperature.

movement of many things, often vehicles, in a specific area.

long, deep depression, either natural or man-made.

worth a considerable amount of money or esteem.

measurement of the rate and direction of change in the position of an object.

crack in the Earth's crust that spews hot gases and mineral-rich water.

chain of volcanoes formed at a subduction zone.

fragments of lava less than 2 millimeters across.

gas such as water vapor or carbon dioxide that is released into the atmosphere by a volcano.

land formed by a volcano rising from the ocean floor.

drop in global temperatures due to volcanic debris in the atmosphere blocking the sun.

an opening in the Earth's crust, through which lava, ash, and gases erupt, and also the cone built by eruptions.

specific danger posed by an active volcano: gas, lahar, landslide, lava flow, pyroclastic flow, or tephra.

scientist who studies volcanoes.

volcanic eruption characterized by a violent outburst of thick volcanic smoke and gas.

state of the atmosphere, including temperature, atmospheric pressure, wind, humidity, precipitation, and cloudiness.

organisms living in a natural environment.

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Related Resources

Plate Tectonics

The Earth’s surface may seem motionless most of the time, but it’s actually always moving, ever so slowly, at a scale that is difficult for humans to perceive. The Earth’s crust is broken up into a series of massive sections called plates. These tectonic plates rest upon the convecting mantle, which causes them to move. The movements of these plates can account for noticeable geologic events such as earthquakes, volcanic eruptions, and more subtle yet sublime events, like the building of mountains. Teach your students about plate tectonics using these classroom resources.

Environmental Hazards

The environmental hazards you face depend on where you live. For example, if you live in northern California you are more likely to be impacted by a wildfire, landslide, or earthquake than if you live in Charleston, South Carolina, but less likely to be hit by a hurricane. This is because the physical conditions in each place are different. The active San Andreas fault runs through California and causes regular earthquakes, while the warm waters transported by the Gulf Stream can intensify a storm heading for South Carolina. These environmental hazards shape human activity regionally. Building codes in California require builders to meet standards set to minimize structural damage in an earthquake and coastal cities have building code to reinforce roofs and walls to resist a storm’s high winds. Learn more about environmental hazards with this curated resource collection.

Volcano

According to the United States Geologic Survey, there are approximately 1,500 potentially active volcanoes worldwide. Most are located around the Pacific Ocean in what is commonly called the Ring of Fire. A volcano is defined as an opening in the Earth's crust through which lava, ash, and gases erupt. The term also includes the cone-shaped landform built by repeated eruptions over time. Teach your students about volcanoes with this collection of engaging material.

MapMaker: Volcanoes

Explore Earth's volcanoes with MapMaker, National Geographic's classroom interactive mapping tool.

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Satellite imagery of volcanoes and volcanic features around the globe.

Volcanoes

A volcano is an opening in a planet or moon’s crust through which molten rock and gases trapped under the surface erupt, often forming a hill or mountain.

Related Resources

Plate Tectonics

The Earth’s surface may seem motionless most of the time, but it’s actually always moving, ever so slowly, at a scale that is difficult for humans to perceive. The Earth’s crust is broken up into a series of massive sections called plates. These tectonic plates rest upon the convecting mantle, which causes them to move. The movements of these plates can account for noticeable geologic events such as earthquakes, volcanic eruptions, and more subtle yet sublime events, like the building of mountains. Teach your students about plate tectonics using these classroom resources.

Environmental Hazards

The environmental hazards you face depend on where you live. For example, if you live in northern California you are more likely to be impacted by a wildfire, landslide, or earthquake than if you live in Charleston, South Carolina, but less likely to be hit by a hurricane. This is because the physical conditions in each place are different. The active San Andreas fault runs through California and causes regular earthquakes, while the warm waters transported by the Gulf Stream can intensify a storm heading for South Carolina. These environmental hazards shape human activity regionally. Building codes in California require builders to meet standards set to minimize structural damage in an earthquake and coastal cities have building code to reinforce roofs and walls to resist a storm’s high winds. Learn more about environmental hazards with this curated resource collection.

Volcano

According to the United States Geologic Survey, there are approximately 1,500 potentially active volcanoes worldwide. Most are located around the Pacific Ocean in what is commonly called the Ring of Fire. A volcano is defined as an opening in the Earth's crust through which lava, ash, and gases erupt. The term also includes the cone-shaped landform built by repeated eruptions over time. Teach your students about volcanoes with this collection of engaging material.

MapMaker: Volcanoes

Explore Earth's volcanoes with MapMaker, National Geographic's classroom interactive mapping tool.

Volcanoes

Satellite imagery of volcanoes and volcanic features around the globe.

Volcanoes

A volcano is an opening in a planet or moon’s crust through which molten rock and gases trapped under the surface erupt, often forming a hill or mountain.


Comments 1 to 50 out of 301:

1960 to the 1990s, after a period of relatively low volcanic aerosol abundance from

1910 (or earlier in the Southern Hemisphere) to

1960. Does this correlate with any ENSO (El Nino) behavior changes? Even if the answer is yes, there are other changes that would or could affect ENSO - some change in solar forcing, changes in human aerosols, both globally and also I would think in spatial distribution, and the anthropogenic increase in greenhouse forcing. There are other modes of internal variability, and while I don't know of specific interactions or explanations, it doesn't require a stretch of the imagination to suspect that monsoons (also affected by aerosols, not that others are not), MJO, QBO, and NAO, NAM, SAM, etc. could be pushing some of ENSO's buttons. I think such a thing as ENSO might be a general expectation for sufficiently wide (east-west) and large oceans along the equator - I've heard that a climate model may produce ENSO like behavior if the Atlantic is widened sufficiently. In the sense that a computer model is a theory, I think there is a theoretical explanation for ENSO at least in general. In so far as what human minds have comprehended, I don't know how far the understanding goes, but I know that typically trade winds push water westward in the tropics, building up a warm pool in the western part of a tropical ocean, and lifting the thermocline in the eastern part - potentially enough to allow upwelling of cold deep water. If a perturbation causes the winds to let up, the warm water may slosh back, and that changes the thermal forcing of the winds, which could allow continued weakenning of the winds, etc. - and the reverse could happen too, it's a positive feedback either way. There are many complexities to add to that picture (double ITCZ in western Pacific, equatorial Kelvin waves, equatorial countercurrent and equatorial upwelling, Ekman pumping), which I am not qualified to go into in so far as ENSO is concerned, but I can speculate that perhaps the temperature difference between the cold upwelling water in the east and the warm pool in the west has to reach some threshold before the positive feedack is strong enough to overcome some other effects that would tend to maintain steadier winds - and a longer period of time for a westward current to remain in low latitude waters could allow a higher temperature increase in the water along the way from regional radiative conditions (more sunlight - and when clouds form they have high tops in the tropics, so they have a stronger greenhouse effect than many clouds elsewhere, I think). ------------------ "Healy Researchers Make A Series Of Striking Discoveries About Arctic Ocean" http://www.sciencedaily.com/releases/2001/11/011129050111.htm Discovery of more volcanic/hydrothermal activity than was previously thought to exist - this does not mean a recent change in that activity has occured. ------------------ "Fire Under Arctic Ice: Volcanoes Have Been Blowing Their Tops In The Deep Ocean ScienceDaily (June 26, 2008)" http://www.sciencedaily.com/releases/2008/06/080625140649.htm nothing about a recent change or any correlation to climate changes. ------------------ "Buried Volcano Discovered in Antarctica" http://www.livescience.com/environment/080120-antarctic-volcano.html An eruption occured 2300 years ago, volcano is still active. " “This eruption occurred close to Pine Island Glacier on the West Antarctic Ice Sheet," Vaughan said. "The flow of this glacier towards the coast has speeded up in recent decades, and it may be possible that heat from the volcano has caused some of that acceleration." " The article never states that an increase in geothermal heating in recent decades has been established, however. "Vaughan noted, however, that the hidden volcano doesn't explain widespread thinning of Antarctic glaciers.". " "This wider change most probably has its origin in warming ocean waters," he said, which most scientists attribute to global warming resulting from human activity, such as the use of fossil fuels. " ------------------ "Kamchatka Volcano Blows Its Top" (July 2007) http://www.sciencedaily.com/releases/2007/07/070705110230.htm "Chile's Chaiten Volcano One Of Scores Of Active Volcanoes In Region" http://www.sciencedaily.com/releases/2008/05/080507105654.htm "Explosive Eruption Of Okmok Volcano In Alaska" http://www.sciencedaily.com/releases/2008/07/080720093810.htm Yes, the location and composition of volcanic eruptions as well as the size/kind of eruption are factors in any climate/weather effects. The greatest cooling can be generally expected from low latitude volcanos because they are most likely to produce a global blanket of long-lived (for aerosols) stratospheric aerosols. Higher latitude eruptions' aerosol distributions may be less likely to cross hemispheres, and the stratospheric circulation each winter tends to bring air toward the poles and then back to the troposphere, so high latitude aerosols may come out of the stratosphere faster. Ash from high latitude eruptions may, depending on exact location, have some chance of landing on snow or ice, reducing the albedo and thus having a local or regional heating effect which would contribute to a global warming effect (until either the snow or ice melts - except for the albedo effect of the earlier melting time if that is involved - or enough new snow or frost falls/forms on top of it). On the other hand, I think any ash cloud hanging over most surfaces except snow and ice would increase the albedo and have a cooling effect, and then there is also the albedo effect of aerosols via their effects on clouds - these effects being more short lived. There is no indication here of a significant change in volcanic activity in recent decades from the previous decades or centuries or beyond. ------------------ "Tectonic Plates Act Like Variable Thermostat" http://www.sciencedaily.com/releases/2007/08/070813171122.htm direct geothermal heat supply still generally wouldn't significantly affect climate, especially global climate, during most of Earth's history except near the beginning. But this could be related to changing rates of geologic outgassing of CO2 over millions of years. ------------------ IN ADDITION TO THE ABOVE: I also found: ------------------ "Could Volcanic Activity In West Antarctic Rift Destabilize Ice Sheet?" http://www.sciencedaily.com/releases/2008/02/080229183818.htm very interesting. no suggestion of current activity or timing of activity in recent geological past. ------------------ "First Evidence Of Under-ice Volcanic Eruption In Antarctica ScienceDaily (Jan. 22, 2008)" http://www.sciencedaily.com/releases/2008/01/080120160720.htm a volcano erupted 325 BC and remains active. "Co-author Professor David Vaughan (BAS) says,"This eruption occurred close to Pine Island Glacier on the West Antarctic Ice Sheet. The flow of this glacier towards the coast has speeded up in recent decades and it may be possible that heat from the volcano has caused some of that acceleration. However, it cannot explain the more widespread thinning of West Antarctic glaciers that together are contributing nearly 0.2mm per year to sea-level rise. This wider change most probably has its origin in warming ocean waters." " ------------------

20,000 yr (precession) cycles that involve changing orientation of the Earth's axis. However, the importance to climate being the change in the axial tilt relative to the orbit around the sun, the body of the Earth itself stays aligned with it's axis the same way - the geographic north pole is still in the Arctic ocean the whole time, etc. Causes of the Milankovitch cycles: gravitational effects of other planets, solar and lunar tidal torques on the Earth's equatorial bulge (The precession cycle, a wobble of the direction of the Earth's tilt relative to it's orbit about the sun, is actually due to a combination of changing direction of tilt and a changing orientation of the semimajor axis of the Earth's orbit). (The equatorial bulge is due to the centrifugal force of rotation - the geopotential surfaces of the Earth, such as sea level, are distorted in such a way that the gravity due to mass and centrifugal force from rotation, as vectors, add to produce an effective gravitational vector locally perpendicular to the surface so that there is no local 'sideways gravity'. PS equilibrium tidal bulges can also be computed by setting 'sideways gravity' to zero. Tidal dissipation of the Earth's rotation and transfer of angular momentum to the moon's orbit result in changes in lunar tidal forces and the Earth's equatorial bulge over time (many millions of years), both affecting the obliquity and precession cycles.) 2. Chandler Wobble and True Polar Wander. As vector quantities, a spinning object has a rotation w which is parallel to the axis of rotation, and an angular momentum L. L is parallel to w if the object is symmetrical about the spin axis - specifically if the spin axis is aligned with a principle axis. (Angular momentum is equal to the rotation times the moment of inertia, but the full moment of inertial is actually a tensor quantity (written as a 3 by 3 matrix) - but if the coordinate axes are chosen to align with the principle axes of the body, 6 of the 9 components are reduced to zero, leaving three moments of inertia, each about a principle axis, so that the component of rotion along each such axis can be multiplied by the corresponding component of moment of inertia to get the component of angular momentum along that axis.) So if the rotation w is aligned with a principle axis, the angular momentum L is also aligned with w and the same principle axis. If there are no external torques applied and the body is not being deformed, there is no wobble. If the three moments of inertia are equal (such as for a perfect homogeneous sphere or a sphere with only spherically-symmetric density variations centered on the center of the sphere), L and w are always parallel. But when the body has different moments of inertia (such as due to an equatorial bulge), then L and w can be in different directions. Without external torques, L must be constant in an inertial reference frame (that does not rotate with the body), but w may shift around, in the reference frame of the body itself, I think both can shift around - the changes over time are described by the Euler Equations. In what can be called the "Tennis Racket Theorem", if w is shifted from a principle axis by a small amount, then: A. if L and w are near one of the 'extreme' principle axes - with the larges or smallest of the three moments of inertia, then L and w oscillate about that axis (specifically I think L traces out a circle about the principle axis though I'm not sure offhand), and so rotation about such an axis is stable. B. But if L and w are initially near the intermediate principle axis, L and w move away from that axis and so rotation about that axis is unstable. The Chandler wobble is a shift of Earth's rotation axis about the principle axis of the Earth most nearly parallel to the rotation axis (this is an extreme principle axis - it has the largest moment of inertia due to the equatorial bulge - the other two principle axes are in (or almost in) the equatorial plane). The spin of the Earth is perturbed by small amounts from the principle axis by earthquakes and seasonal mass distributions, but rotation about this axis is stable. (And over time, some kind of viscous dissipation would actually tend to return the rotation axis to alignment with the principle axis - for fixed L in an inertial reference fram, such alignment minimizes the square of |w| and thus minimizes the rotational energy, on Earth, the spin axis is never found more than

10 meters** (much less than climatologically insignificant) from the principle axis at the Earth's surface, and the period of the Chandler wobble is

440 days** - this specific info is found on p. 261 of Classical Mechanics: A Modern Perspective. Second Edition. Vernon Barger and Martin Olsson. 1995. **Caution - most info is fairly correct but I have found a few specific numbers in that book which were wildly off - the mass of Venus on p.396, and I think the rate of tidal damping and the rate of lunar orbital change by tidal damping were also off.) 3. The two moments of inertia about the principle axes in or near the equatorial plane are about equal. However, if a supercontinent persisted in mid-to-high latitudes for a time and heat built up in the mantle beneath (continental crust is of course thicker but also has more radiactive heating per unit volume than oceanic crust, both of which have more than the mantle) so that the supercontinent were elevated, conceivably if this were extreme enough (I'm not sure how far this would have to go or how likely it is it could ever get that far, especially in the distant past when the equatorial bulge would have been larger), the principle axes could be shifted out of alignment from the spin axis enough and maybe the principle axis nearest the spin axis would become an intermediate axis (? or maybe that part's not necessary) and then the rotation becomes unstable ?? - or maybe it doesn't become unstable ?? - but the end result is that the supercontinent ends up at low latitudes so once again the principle axis with the largest moment of inertia is close to the spin axis. This process shifts the whole body of the Earth around, this is true polar wander. PS if this ever happenned - conceivably it might happen (that's the impression I have as of yet) faster than it takes for the equatorial bulge to deform back to equilibrium, which means parts of the equatorial bulge could be shifted into higher latitudes - the ocean would of course respond much faster, so parts of the mid-to-high latitudes could have 'land' made of exposed oceanic crust (which could result in much release of CH4 from hydrates/clathrates) while parts of the equatorial ocean would be extremely deep. But it depends on how fast or slow the different processes occur relative to each other. The only hypothesized instances of true polar wander on Earth that I know of would be in the late Neoproterozoic, and I don't know what the state of the evidence is for it. 4. And of course over time there is continental drift as the plates grow at rifts or ridges and go back into the mantle at subduction zones. Faster plate movements should tend to correspond to greater geothermal heat transport to the surface, wider mid-ocean ridges and thus higher sea levels (although I read something recently. ), and faster geologic CO2 emission. At first glance (could be wrong?) it would also make sense to expect faster mountain building and thus an enhanced erosion rate (with some time lag) - which itself would at least partly counteract the tendency for a warmer climate to sustain an equilibrium elevated CO2 level by causing faster geologic sequestration of CO2 to balance the faster CO2 release. At first glance it also would make sense to expect more frequent eruptions of all or many kinds, including those explosive low-latitude eruptions that have a short-term cooling effect - but collectively over time this would have a persistent cooling effect, but CO2 builds up over time and eventually would have the larger effect on long-term climate. The size of the plates would also have an effect - smaller plates would require a longer total length of plate margins, which could correspond in part to a longer length of mid-ocean ridges, etc. Globally the average geothermal heat loss is

0.1 W/m2, even if it could have been doubled

100 million years ago or whenever, that would still only be

0.2 W/m2. It's a small climatological forcing and it doesn't change very fast, in contrast, doubling CO2 is a forcing of about

4 W/m2, a 1% increase in solar TSI would be a forcing of about 3 W/m2. Have to take a break now.

100 million years, associated with the long-term solar brightenning over it's stellar lifespan. (A formula for solar TSI as a fraction of the present day value is 1/(1 - 0.38*t/4.55), where t is the number of billions of years from now, negative for in the past. This is an approximation that may be innaccurate for near the beginning or end of the solar lifespan - I got it from a paper by James Kasting, forgot which paper. From this formula, solar TSI as a percent of present day solar TSI: 75.0 % at 4 Ga (billion years ago) 80.0 % at 3 Ga 82.7 % at 2.5 Ga 85.7 % at 2 Ga 88.9 % at 1.5 Ga 92.3 % at 1 Ga 93.0 % at 900 million years ago (Ma) 93.7 % at 800 Ma 94.5 % at 700 Ma 95.2 % at 600 Ma 96.0 % at 500 Ma 96.8 % at 400 Ma 97.6 % at 300 Ma 98.0 % at 250 Ma (

Paleozoic/Mesozoic boundary) 98.4 % at 200 Ma 99.2 % at 100 Ma 99.6 % at 50 Ma . and in the future: 104.4 % in 500 million years 109.1 % in 1 billion years 120.1 % in 2 billion years ---------- And 'wobbles' in mantle convection and continental drift - these wobbles are analogous to day-to-day weather changes in the atmosphere, it is mantle weather. The weather reshapes itself in (depending on the weather features in question - I'm thinking of midlatitude synoptic-scale features) days as the winds reshape the pressure variations (depending in part on temperature variations) that shape the winds. In the mantle, momentum (and therefore the coriolis effect) is negligible, pressure gradients (due to density variations) drive motion against friction. The density variations that force the motion cannot change much faster than the motion itself - thermal diffusion being a much slower process. So large rapid changes in mantle convection and continental drift don't happen. But over many millions of years, the mantle and lithospheric weather will change, as cold slabs of material descend down from subduction zones, continents collide, and material is no longer fed to the descending slab, while the remaining slab continues descent, as continents overide midoceanic ridges, as heat builds up within the mantle near the core or perhaps around pieces of recycled crust to produce buoyant plumes, and as heat builds up under supercontinents, and as continents rift apart and sink a bit. Continents individually are warped and tilted, rise, and sink, as the move over density variations in the underlying mantle (a slow process). Over a long time, one might define a mantle climate. One kind of mantle climate change could then be the transition from layered convection to whole mantle convection. Whole mantle convection is simply convection cells with updrafts and downdrafts extending from top to bottom. In layered convection, the mantle would convect in two seperate layers (boundary at about 660 km depth from surface). When there is a boundary to convection (the top of the mantle, the bottom of the mantle, the bottom of the outer core, and possibly at 660 km depth in the mantle), heat must be transported by conduction to the next layer, which requires a higher thermal gradient, so heat can build up in the lower layer relative to the upper layer. Why would there be two layers of convection? As pressure increases with depth, material is compressed, this is associated with an adiabatic lapse rate where temperature rises or falls within a mass without the conduction of heat. But in solids there can also be phase transitions (I've also heard of different liquid phases of the same substance but . ). As with the phase transitions of melting/freezing and evaporation/condensation, a solid phase transition may involve a change in heat as well as density. Obviously as pressure increases, phase transitions to higher-density phases are favored. If a phase transition gives off latent heat (like condensing of water vapor to form clouds), than that transition will occur 'sooner' at lower temperature - more specifically, the Clapeyron slope dp/dT = change in entropy / change in volume, where dp is the change in pressure of an equilibrium phase transformation with a change in temperature dT. There are multiple phase transitions within the mantle from about 410 to about 660 km from the surface. The Clapeyron slope of the 660 km phase transition (which, going down, involves a change of much of the mantle's material to a perovskite crystal structure) 660 km is a nominal position used for identification - the actual position varies) is negative, which means that at higher temperature, the phase transition occurs at lower pressure. Without phase transitions and in the absence of significant coriolis effect, warmer material at a given pressure will generally rise and colder material will sink due to the effect of temperature on density. But as warmer or colder material rises or sinks across the 660 km phase transition, the actual position will rise or fall, respectively, due to the temperature change, and this produces a density variation that is opposite that caused by the temperature variation, and if strong enough, will produce a force that prevents convection across the boundary. From what I have read (not much, really), I've gotten the impression that there is some layered convection and some whole mantle convection at present, earlier in Earth's history, there may have been mainly just two-layered convection, and perhaps changing conditions caused a transition toward some whole mantle convection around the time of the Archean-Proterozoic transition (?). Why would that happen? - well, material properties change with changing temperature, as the mantle as a whole cools, the 660 km transition should gradually rise upward overall - in the future, if it goes far enough, it would catch up with other phase transitions (which, if they have positive Clapeyron slopes, would be moving downward - where they meet I would expect a new phase transition to occure with an intermediate Clapeyron slope) . not all of the mantle substance actually goes into the perovskite structure, . the overall viscosity increases over time with decreasing temperature overall . layered convection would allow heat buildup in the lower mantle relative to the upper mantle, so perhaps the temperature difference could have become so great that eventually it overcame the impediment to whole-mantle convection ? - if that's how it works, then one would expect episodic whole mantle convection, after each episode of which, the temperature change with depth would be reduced and so one would go back to two-layer convection - but I'm not sure that's how it would have worked - anyway, the advent of whole mantle convection could then have increased the cooling of the core, which would affect inner core growth rate (ps that liberates latent as well as buoyant composition variations, which help drive outer core convection, which of coarse powers the magnetic field), and this could also affect the geochemistry of the layers and the crust (?). BUT also so far I have been describing phase transformations as being at equilibrium, but particularly in colder material, it isn't so easy for atoms to rearrange themselves, so phase transformations can be delayed beyond equilibrium, and the resulting microstructure that results when the phase transformation finally occurs can affect the viscosity (and/or rigidity?) of the material, and this would apply to the behavior of cold descending slabs coming from subduction zones. The rate of subduction affects the temperature of the slab, which affects the position and result of phase transformation, the effect on rigidity, and that could affect whether or not the descending slab penetrates into the lower mantle or comes to rest on the 660 km boundary . SEE Karato, "The Dynamic Structure of the Deep Earth" --- 5. "We almost went extinct once already" Would you be refering to the supereruption of Toba about 75,000 years ago? While it did occur as an ice age was starting or setting in or growing stronger, a supereruption's effects would be particularly sudden, and eventually would have subsided into the background as Milankovitch forcing went on - of course there would be some climatic inertia from any buildup of snow/ice during the cooling from the supereruption. A supereruption, as with single eruptions and earthquakes, etc, are episodic events, and takent one at a time, not necessarily indicative of any overall trend in continental drift, mantle convection, or geothermal heat fluxes.

380 ppm of CO2 in the atmosphere and some similar amount (in terms of total amount, not concentration) in the ocean. We could easily get it to 400, 450, 500, 550, 600, 700, 800, 1000, . ppm if we 'wanted to'. We are also responsible for the CH4 increase from

1700 or 1800 ppb. "Your TSI table" . "that is a long gradual process and has not much to do with the current situation." Yes. "The extinction I was referring to was during out split in Africa before we were fully human and only numbered in the thousands during a period of severe climate change. But rather than extinction it resulted in increased genetic diversity. " A bottleneck in the population should always reduce genetic diversity, that's not to say that genetic diversity might not increase faster than otherwise depending on the aftermath. What I have heard about the Toba eruption is that humans would have numbered

10,000 or something like that in the aftermath. However, I think Homo sapiens sapiens were on the scene already, although Neanderthals (technically also Homo sapiens, but not Homo sapiens sapiens - if I have my names right) were still around. "My point is that the reason our planet is so active is gravitational stresses. Tidal stress from the moon plays the largest role. But when compounded by gravitational stress from other solar bodies we see cycles occur." My understanding is that most of the tidal energy dissipation occurs in the ocean and some fraction of that helps (along with wind-driven motions) mix the ocean so that it is less stratified than it otherwise would be. From: Oceanography: tides by Dr J Floor Anthoni 2000 http://www.seafriends.org.nz/oceano/tides.htm Total tidal energy dissipation rate: 3.75 +/- 0.08 TW, Of that, most - 3.5 TW - is dissipated in the ocean. The area of the Earth is about 510 trillion m2, so 3.75 TW is a global average of about 0.0074 W/m2, that's roughly a tenth of the geothermal heat flux from the surface. There will of course be some pulsation in the tidal dissipation, but the average over half a lunar month won't change as much, and the average over a year, over 18 years, etc. will vary considerably less. And less than a tenth of that would be dissipated within the solid Earth, core, and atmosphere. (maybe more on that later*) "What would happen to Earth if the moon was only half as massive? http://www.sciam.com/article.cfm?id=half-mass-moon (this approximately gives the same rate of lunar orbit growth given in the 'seafriends' website.) MORE: __________ Tides and ocean: Significant dissipation of tidal energy in the deep ocean inferred from satellite altimeter data G. D. Egbert and R. D. Ray (a lot of handy numbers there) "OCEAN SCIENCE: Enhanced: Internal Tides and Ocean Mixing Chris Garrett" http://www.sciencemag.org/cgi/content/summary/301/5641/1858 http://www.aviso.oceanobs.com/en/applications/ocean. ----- http://oceanworld.tamu.edu/resources/ocng_textbook/contents.html http://oceanworld.tamu.edu/resources/ocng_textbook/chapter17/chapter17_04.htm http://oceanworld.tamu.edu/resources/ocng_textbook/chapter17/chapter17_05.htm --- "Tides dissipate 3.75 ± 0.08 TW of power (Kantha, 1998), of which 3.5T W are dissipated in the ocean, and much smaller amounts in the atmosphere and solid Earth. The dissipation increases the length of day by about 2.07 milliseconds per century, it causes the semimajor axis of moon's orbit to increase by 3.86cm/yr, and it mixes water masses in the ocean." --- "The calculations of dissipation from Topex/Poseidon observations of tides are remarkably close to estimates from lunar-laser ranging, astronomical observations, and ancient eclipse records. Our knowledge of the tides is now sufficiently good that we can begin to use the information to study mixing in the ocean. Remember, mixing drives the abyssal circulation in the ocean as discussed in §13.2 (Munk and Wunsch, 1998). Who would have thought that an understanding of the influence of the ocean on climate would require accurate knowledge of tides?" Here's section 13.2: ----- __________ Tides, wind and ocean: 50 Years of Ocean Discovery: National Science Foundation, 1950-2000 ----- For some reason I didn't copy the website for this one, but I must have it saved somewhere in my 'favorites', but anyway: "Modelling global and local tidal dissipation rates E. Schrama": "Oceanic tides are a wave phenomenon set in motion by the gravitational work of Sun and Moon. Traditional geodetic and astronomic techniques allow one to assess the global rate of energy dissipation. Satellite altimetry brings this problem one step further, now making it possible to locally estimate the rate of conversion of barotropic tides into internal tides that initiate deep oceanic mixing." "The global dissipation budget strongly suggests that most of the energy in the tides is lost in the ocean,": 2.4 TW lost in ocean from semidiurnal lunar tide M2 0.1 TW for M2 solid Earth tide 0.2 TW atmospheric dissipation for S2 "Our results confirm that": M2 wave dissipates 2.42 TW, of that: approx 1.7 TW dissipated in coastal seas by friction, 0.7 dissipated in deep oceans "Suggested in literature is internal wave generation and the relevance is that this process is responsible for mixing between lighter surface waters and the deeper ocean. The hypothesis by W. Munk to explain the oceanic density stratification is that about 2 TW is required for maintaining this balance, Egbert and Ray were the first to suggest that about half of this amount could come from tidal mixing, the remaining part could come from wind induced mixing." ----- http://www.agu.org/meetings/wp06/wp06-sessions/wp06_OS15B.html __________ Wind and ocean "The Work Done by the Wind on the Oceanic General Circulation Carl Wunsch" http://ams.allenpress.com/perlserv/?request=get-abstract&issn=1520-0485&volume=28&page=2332 "Improved global maps and 54-year history of wind-work on ocean inertial motions Matthew H. Alford" http://opd.apl.washington.edu/scistaff/bios/alford/assets/Alford2003.pdf http://opd.apl.washington.edu/scistaff/bios/alford/alfordglobalmap.html OTHER undifferentiated: http://www.aviso.oceanobs.com/fileadmin/documents/kiosque/.http://www.jamstec.go.jp/esc/publication/annual/annual2006/.http://www.sciencedirect.com/science?_ob=ArticleURL.

0.54 m (my calculation from math and physics) or 0.56 m according to the physics book mentioned earlier in the Chandler wobble discussion. Some notes from the Karato book mentioned earlier: Total heat flux from the core: estimated from

3 to 10 TW. Energy needed to drive the geodynamo (in terms of thermal energy or mechanical energy? - not sure): roughly 0.1 to 1 TW. Because the outer core is convecting, the total heat flux from the core must be greater than that which would be conducted through material at the adiabatic lapse rate (about 0.7 K/km for the outer core) (remember this is liquid metal alloy, thermal conductivity

40 W/(K m), about 10 times that of surface rocks). The estimated conducted heat from the core

4 TW. (This conducted heat would be unavailable to drive the geodynamo. However, the process of forming the inner core, in addition to giving off latent heat, concentrates some (likely) buoyant impurities, which will then rise - this buoyancy from compositional heterogeneity cannot conduct very fast, and so could drive some convection itself). Cooling of the core by 100 K every billion years would release 5.7 TW of heat (I'm assuming that includes latent heat from solid core growth. The reason for the solid core growing from below is that the melting point rises with pressure, as the solid phase is denser than the liquid phase. The same is true of the mantle - if the mantle were gradually heated up, one of the first parts to melt would be the near the top. In fact it is partial melting upon ascent (even as it cools adiabatically from decompression) that produces the crust and lithosphere (according to Karato, upon some partial melting, dissolved water is lost from what becomes the lithosphere - making the lithosphere more rigid - so the asthenosphere (below the lithosphere) is softer not because it is partially molten but because it has not undergone sufficient partial melting to liberate water (in addition to being warmer, of course). Because the mantle is not a pure substance, it doesn't have a single melting point, and melting and freezing involve chemical differentiation - more generally, this concept helps explain the variations in igneous rocks.) The scale of fluid velocity of the outer core has been estimated at around 0.1 mm per second (thats FAST for a deep geophysical process!). That's about 8.6 m per day! Compare that to the motion required to catch up to tidal deformation. Based on an ideal heat engine, the conversion of the heat driving the outer core convection to mechanical energy is

26.8 % or 28 % efficient, based on top and bottom temperatures of 4100 K and 5500 K, and of 3600 K and 5000 K, respectively - that's based on all the heat going in at the bottom, however, which won't be true, although much of it may be (from latent heating). So of the heat that goes into driving the convection, perhaps between 70 % and 85 % (halving the efficiency to approximate the effect of internal heat sources only) would then go on to the mantle. Of course, some of the mechanical energy goes back into heat anyway, and some goes into electromagnetic energy, but some of that may go back into heat within the core (but I'm thinking it would go back into heat always at lower temperature (higher up within the core) than where it went into mechanical energy, so that entropy increases), . etc. The mantle and crust have there own heat sources (aside from the heat liberated upon cooling, this is where most radioactivity is - radioactive elements increase in concentration from the core to the mantle, to oceanic crust, to continental crust). I think the total geothermal heat flux at the surface is somewhere around 40 TW. Much of that is conducted through the crust (or for heat generated within the crust, conducted through part of the crust) in the final part of it's journey. If a typical thermal conductivity of crustal material were 2 W/(K m) and the thermal gradient in that material were

30 K/km, that's a heat flux per unit area of

0.06 W/m2 - if that's typical, that's a large fraction of the total heat flux at the surface. Although concentrated in geologically active areas, much of the heat leaving the Earth from below the surface comes through geologically quiet regions of the Earth's crust.

400 km depth, all the olivine transforms to 'Beta (Mg,Fe)2SiO4'. Then with increasing depth, eventually all pyroxene goes into the garnet phase, and a small portion of the 'Beta' does as well. Somewhere at or just below 500 km depth, all remaining 'Beta' is transformed to a spinel crystal structure that isn't Beta. Going deeper, Garnet starts going into Ca-perovskite, the amount of Ca-perovskite gradually increasing, meanwhile, near 600 km depth, garnet also starts going into an 'ILM' phase, which increases gradually until a depth of 650 km. At 650 km, all 'ILM' and a majority of the spinel go into Mg-perovskite, and the rest of the spinel phase goes into Magnesio-wustite (double dots above the u in 'wustite'). Below that, the amounts of both Ca-perovskite and Mg-perovskite increase gradually from the garnet until all garnet has been converted, which occurs somewhere below 700 km. From p.19, the 'beta spinel' is also called wadsleyite, or modified spinel, and the spinel below 500 km is called ringwoodite.

300 times the surface value (30 microTeslas) (B of a typical refrigerator magnetic is about 100 times the natural B at the surface). I think field energy density is proportional to the square of B, in which case the energy density is between 9 and 90,000 times the surface value, the volume of the core is

16 % the volume of the Earth (more than 1/9) (for future reference, surface area of core

30 % that of the whole Earth (which implies the mass of the core is about

30 % the mass of the Earth, since gravitational acceleration is nearly constant within the mantle (that's somewhat of an accident of the specifics of the Earth's mass distribution, not a general principle)), radius of core

54 % that of the whole Earth), the magnetic field changes wouldn't induce much of a current in the mantle and the mass of the magnetosphere and E-region dynamo are very small, so it makes sense to think that most of the geodynamo energy goes back into the heat energy of the core. Any mechanical and electromagnetic energy going back into heat within the core also includes that coming from composition-generated buoyancy. (But I think some small portion of electromagnetic energy must radiate away into space as the Earth moves and the field changes.) As long as I'm on this, notice that 'stretching' the field lines, contorting them by uneven fluid motions, increases the magnetic energy density by putting a greater length of field lines into a unit volume. An interesting analogy could be made between that and the conversion of potential to kinetic energy in the atmosphere to sustain nearly-geostrophic wind shear as isotherms are elongated (without changing the average temperature gradient), such as by a growing wave pattern. There are big differences but there's a cool geometric similiarity. --- "And then you need to add the extra gravitational forces from jupiter and full alignments. If they can affect the sun they can certainly effect the Earth." The vast majority of tidal forces on Earth is from the moon and sun (solar tides being about half the magnitude of lunar tides, I think (roughly from memory ratio of masses divided by cube of ratio of distances:

0.44 - just under half). Remember planetary tides on the sun from: http://blogs.abcnews.com/scienceandsociety/2008/07/global-warming.html#comments A more complete comparison: height of equilibrium tidal bulge raised on sun by planet, as fraction of that raised on earth by moon, [ignoring out-of-equilibrium complexities of crust,ocean reaction (no Bay of Fundy on sun?)] expressed as ppt (parts per thousand): Jupiter: 1.33 Venus. 1.27 Earth. 0.590 Mercury: 0.563 Saturn:. 0.0647 Mars. 0.0179 Uranus:. 0.00122 Neptune: 0.000375 Pluto. 0.0000000191 SUM. 3.84 Tidal acclerations at solar surface generated by planets, as ppt of lunar tide on earth, : Jupiter: 0.340 Venus. 0.325 Earth. 0.151 Mercury: 0.144 Saturn:. 0.0165 Mars. 0.00458 Uranus:. 0.000311 Neptune: 0.0000957 Pluto. 0.00000000488 SUM. 0.981 The sums would be approached when Venus and Jupiter and a few others are aligned or close to aligned with the sun. When Jupiter-Sun-Venus forms a right angle, the tides on the sun will be more limited. (PS notice Saturn plays a much larger role in the 'solar jerk' (where the importance of a planet is proportional to it's mass times it's distance) than it does in tides on the sun (mass divided by distance cubed). This would have some implications for Fairbridge's concepts. It would also be instructive to consider the product of the above numbers, which gives the tidal acceleration that acts on the tidal bulge: In ppm of equilbrium lunar tides on Earth: Sum of products. 1.04 Product of sums. 3.77 Jupiter by itself: 0.454 The distinction between the first two is a nonlinearity. This is the tidal force per unit area of the sun per unit density variation with depth at the sun's surface, relative to a theoretical equilibrium lunar tide on Earth. The density variation within the Earth is distributed with some significant concentration near the surface and near the core/mantle boundary. The mass of an equatorial bulge is produced by the vertical displacment of a density contrast. The density variation within the sun is quite small near the surface, one has to get almost halfway to the center before the density is comparable to the ocean,

60 % of the way to the center to find densities similar to that of the Earth's mantle, the great majority of the Sun's mass is contained within half it's radius from the center. to be continued.

1 % of the mass of the sun lies above, so the equilibrium tidal bulge is rather close to 0.8^4 = 0.1^4 * 2^12 =

41 % of the surface value. Keep in mind that the equilibrium lunar tide at the Earth's surface has a range of

54 cm at the surface, or close to 16 cm at the core/mantle boundary (I say close to because while g is nearly constant in the mantle, it is not precisely constant), for what it's worth, at 10 Earth radii from the center of the Earth, it would be 5.4 km. If all the planets were aligned with the sun, the equilibrium tidal range at the sun's surface would be about 2.1 mm (close to how much your hair would grow in 5 in 6 days - and points on the sun would go through this range in a bit over 10 days, I think (half solar rotation period)) - at 20% below the surface, 0.86 mm, for what it's worth, at 10 times the solar radius from the sun's center, it would be 21 m (69 feet). to be continued.

9.81 m/s2 = G*massEarth/(radiusEarth^2) -- Moon's mass is about Earth's mass / 81 Moon's (average) distance from Earth is about 60.3 Earth radii. 1/81 * [(1/59.3^2)-(1/60.3^2)] = 0.12 ppm -- So the difference in lunar g from Earth's center to the sublunar point at Earth's surface, as a fraction of Earth surface g: 0.12 ppm. That's 1.1 microns per second squared. to be continued.

0.1 ppm. I don't know what stress that would require within the crust offhand. If the whole Earth responded in the same way, the same would be true for the oceans - the vertical depth changes would be small because most of the surface changes would be supplied by changes in the sea floor (and there would be no noticeable changes at the coasts). But the ocean doesn't respond the same way, so the horizontal displacement in the open ocean may be on the order of a kilometer (which the coriolis force may act on so that water parcels move in loops). The changing water depth would also affect changes in the underlying crust and mantle, so it's complicated. Of the energy that is going into the tidal displacments, some comes back out - the 'elastic' fluid motion of the ocean (and outer core in as far as that's concerned), and the elastic deformation of the solid Earth (includes the mantle - it responds more rigidly to high-frequency cycling, plastic deformation takes time). Energy is lost to viscosity in fluid motions and in plastic deformation, electrical resistance in the core, and to any brittle failure that would occur, as well as microscopic fractures. (PS atomic spacing may vibrate about equilibrium spacing, where equilibrium is at the bottom of an 'energy well'. Over small vibrations the energy well is approximately parabolic, so there is a linear proportion of force to deformation (strain). But when atoms are pulled apart, the energy approaches a modest limit, whereas pushed in close enough and the energy shoots way up. Thus, extreme compression can store so much energy that when released, the atoms could fly apart (vaporization).) Anyway, not much tidal energy is lost outside the oceans on Earth. More energy may go into the solid Earth tides then is dissipated there because the energy can come back out to the extent that the Earth 'springs' back. -------------- At the surface of the sun, with all planets aligned, tidal acceleration is 0.981 ppt of the lunar tide on Earth's surface. That's on the order of 1 nm/s2. At 10 solar radii out from the center, it would be on the order of 10 nm/s2. I'm not sure how the solar wind's velocity varies as it moves away from the sun - it would be decelerated by gravity but it is also affected by the magnetic field (and vice versa). For the sake of having some ballpark figure: at 100 km/s, it takes

7,000 seconds to cross a solar radius. In 70,000 seconds, the time taken to cross 10 solar radii, the tidal acceleration would make a difference in velocity on the order of 0.7 mm/s. Even out 100 solar radii, tidal acceleration might cause a variation on the order of 7 mm/s. It seems rather insignificant compared to a speed of even just 10 km/s, let alone 100 km/s or 500 km/s. Of course, while I've been mentioning tidal accelerations out to 10 Earth radii and 10 solar radii, I should mention that the formulas for tides I've been using are nice linearizations - approximations that will fail when the distance out becomes significant compared to the distance to the tide-generating mass. However, for a tide generating object a distance R from the center of the body experiencing tides, the approximation is not off by more than a factor of 10 within

75 % of R toward the tide-generating mass, or

5 times R in the opposite direction, it's not off by more than a factor of 2 within 1/3 R toward the tide-generator or just over half of R in the opposite direction.

10 m/s2, would be 200 ppm = 0.2 ppt less dense - 0.2 ppt * 4000 kg/m3 = 0.8 kg/m3, over the depth of the column, a difference of 0.8*1000*500 kg/m2 = 400,000 kg/m2. Times gravity: a pressure difference of

4 MPa (about 40 atmospheres,

600 psi). Subducting slabs on average are cooler than the surrounding mantle by several hundred degrees (Karato p. 129), although they don't descend straight down so having a 500 km column would be unlikely, I think. .

2200 Pa. Tidal stress from horizontal tidal acceleration acting over 6000 km (this is just to get a sense of the order of magnitude - PS that 10 K warmer bit- just to see what's possible, I don't know what the typical temperature variation is outside of those descending lithospheric slabs.): 60/5 * 2200 Pa = 26400 Pa =

4 psi - that would be the kind of stress you'd see in the crust directly from the tidal forcing of the moon. But the oceanic response would exert other stresses in the crust. 0.54 m * 1000 kg/m3 * 10 m/s2 =

less than 1 psi. What about shear stresses.

4 psi. Unless the asthenosphere and below didn't hold themselves against it but pushed up or pulled down on the crust above. with constant mass per unit area and constant tidal acceleration with depth, it would increase by a factor of

60 within the crust and lithosphere. BUT tidal acceleration drops to zero at the center, so it would only be a factor of

30 - AND mass is concentrated at depth but area declines. per unit area at the surface, underlying mass is somewhat concentrated higher rather than lower, . Well, you get the idea. 30 * 4 psi = 120 psi. But plastic deformation takes time, the core wouldn't hold itself against shear but the mantle would somewhat. well I did a visual estimate from a graph and came up with a factor of 2.35/6.37 *63.7 = 23.5, 23.5 * 4 psi = 94 psi =

0.6 MPa - that's if the mantle acts like liquid, which I wouldn't expect, so it's likely a bit less than that, and perhaps closer to the original 4 psi. --- Dissipation: cracks: well, 100 psi =

0.6 MPa is the pressure found at 60,000/3000 m = 20 m below the surface - well, between 20 m and 30 m depending on the type of rock - the point is, any tensile stress due to tides is still, except in a very thin layer on top of the crust, just a reduction in the compressive stress due to the pressure. So brittle failure by pulling apart would be odd. I would expect heat and compression to, over time, weld cracks shut, which would limit the ability of many millions of tidal cycles to build up weaknesses in the material. (PS I've really gotten away from things I really know about here, but I suspect both heat and pressure combine to make the lower crust less brittle than the upper crust. This has an interesting effect on the deformation and fracturing patterns one may see in a cross section of mountain ranges (fractures tend to curve to near horizontal at depth - at least in the drawings I'm remembering - is that because of the reduced tendency to brittle failure at depth and/or is it something else?). Also, I think higher pressure increases viscosity, and from what I recall, below the asthenosphere, viscosity increases downward (until the core, of course).) There are, of course, 'pre-existing' cracks - joints and faults - I doubt the tides could ever pull these apart completely anywhere, but it could very slightly reduce compression, which might then reduce the threshold of shear stress necessary to cause sideways slips (which is the motion that would occur along any fault's plane) - so statistically one might look for earthquake (and volcanism) frequencies relative to variations in tides. But I wouldn't expect anything big. The presence of these faults and joints would also reduce the amount of tension that could be realized in the intervening rock. A little bit. Slightly. I'm downplaying it because it's not like the crust is just sitting there in space - it's stuck to the mantle. Even if there were a clean break all the way through the crust and lithosphere (and not just in the sense that the mantle is poking up through it), the mantle underneath would still transfer tensile stress to the crust above by pulling on it sideways (the horizontal shear stress). Dissipation: heat - atoms have to move around in a phase transition, conceivably, even in a short period, some portion of the atoms near phase transitions in the mantle might be cycled through different arrangements (statistically - I wouldn't imagine the phase transition is knife-edge, or that on that timescale it could get near equilibrium (?), and there are the gradual phase transitions from or to garnet, so I wouldn't expect it's the same atoms each time around) - that might be a location where there is some relative concentration of tidal dissipation into heat energy. Not that it would be a significant source of heat. I would try comparing it to the radioactive heat generation in the mantle per unit volume if I had the time. Back to tidal accelerations of charged particles - in the Earth's magnetosphere, at 10 Earth radii from the center of the Earth, for example, tidal acceleration is on the order of 11 um/s2. How fast do charged particles travel in the magnetosphere of the Earth? I really don't know, so this is just a sample calculation, to be multiplied by whatever corrective factor is necessary later: How about 4 km/s ? At 10 Earth radii, it would then take on the order of 70,000 km path to cross a region of tidal acceleration in one direction. 70,000 km / (4 km/s) = 17,500 s (several hours). 11 um/s2 * 17,500 s =

190 mm/s. So the lunar tides could be expected to alter particle velocites in the magnetic field of the Earth at 10 radii out by on the order of 0.2 m/s, 1/20,000 of their velocity - if they are moving at 4 km/s. Of course, that doesn't account for the paths they take, typically a helical path rebounding from polar region to polar region along magnetic field lines, with either an overall eastward or westward drift (it may just be one or the other, or depend on charge, I forgot which). This means their east-west motion is quite a bit slower than their north south motion (overall, averaging over each turn of the helix), so they would pass through the same tidal acceleration field multiple times. However, if they are rotating with the Earth (I'm not clear on that part), that eliminates that concern (unless they are drifting west at high speed). otherwise, they may come out of high tide drifting outward, drift east/west and then drift back down after passing low tide . If it took

20 hours (70,000 seconds) to exit a high tide or low tide, they might accumulate an extra velocity of

0.8 m/s, which over 70,000 seconds would mean a displacement of

56 km, which isn't much out of 70,000 km. ____________ Bottom line on tides: Yes they have effects, but outside of oceanic processes, they're really small. Oh, and (you probably realized this but it bears mentioning) tidal dissipation is not fixed by tidal forcing - if the Earth's properties (spin rate, ocean basin shapes and locations, natural frequencies, material properties) were different, tidal dissipation might be much higher or lower. If the tidal deformation were perfectly elastic, their would be no tidal dissipation - the Earth wouldn't be slowed down by the tides - which means there wouldn't be a net torque on the tidal bulges - for simple equilibrium bulge shape, that would imply the tidal bulge is either completely in phase (high tide occurs with moon overhead) or completely out of phase (high tide occurs with moon setting or rising, as seen from equator). On that note: A couple of interesting papers on the topic of tidal changes over geologic time (and one also discusses Milankovitch cycles): http://journals.cambridge.org/download.php?file=%2FIAU%2FIAU2004_IAUC197%2FS174392130400897Xa.pdf.http://www.journalarchive.jst.go.jp/jnlpdf.php?cdjournal=pjab1977&cdvol=69&noissue=9&startpage=233. Which reminds me - if you went back in time far enough, you might reach a point where the tides (on Earth) were quite a bit more influential in things. Also, with solar tides included, that's almost a 50 % increase or decrease in tidal acceleration and tidal displacements from the lunar tides alone. That implies the tidal torque, a product of the two (integrated over the tidal density perturbation, multiplied by . etc.), ranges from just under 1/4 of lunar tide alone at neap to around 2 times lunar tide alone at spring tides (with a reduced range when the moon is farther from the ecliptic). This is nonlinear. However, the average effects (on the torques) should add up linearly - this is because, over time, the lunar tidal bulge rotates relative to solar tidal forcing, so that the average solar tidal torque on the lunar tidal bulge is zero - and it works the other way around, too - well, almost, there's a correction to be made from the eccentricities of the orbits, although the tides will be smaller during the time of the month when the moon is moving slower, so.

20 years? The biggest change beyond the tides themselves: spring-neap. Granted their is nonlinear behavior, particularly near coasts, etc. But I'd still expect most of the variation to be in the semimonthly spring-neap cycle. --- " "well, almost, there's a correction to be made from the eccentricities of the orbits, " - applies to both solar and lunar tides. " And there could be significant interaction beyond linear superposition of tidal bulges when one gets into coastal areas, shallow areas connected to deeper water. etc. (for example, when the beach slopes into the water (typical), one tide raises the water and brings it inland a little, another tide raises it more and brings it in farther - the combination of higher water and water farther inland might make the local volume of water involved proportional to the square of the sums of the tides. etc. - and obviously there is threshold behavior - if you are higher up you'd only get the highest high tides. etc.) -------- Sloshing Inside Earth Changes Protective Magnetic Field By Jeremy Hsu Staff Writer posted: 18 August 2008 http://www.space.com/scienceastronomy/080818-mm-earth-core.html "The Earth's overall magnetic field has weakened at least 10 percent over the past 150 years, which could also point to an upcoming field reversal." - or not. I saw a graph showing this gradual decline as part of a cycle, based on some archeological data, although I don't know how that idea has held up (I think it was in "The Cambridge Encyclopedia of Earth Science(s?)", from 1980, so it's been awhile. Otherwise, nothing in the article really indicates that what is happening is unusual in the past century or two or five or ten or twenty.

3 W/m2. Anthropogenic CO2 forcing is somewhere around 1.6 W/m2, which is about 1 % of 155 W/m2, of course. But the total anthropogenic greenhouse gas forcing is over 2 W/m2, anthropogenic aerosol cooling may bring total anthropogenic forcing down to . 1.7 (?) W/m2. If the climate sensitivity without feedbacks is 0.3 K/(W/m2), then the

155 W/m2 preindustrial greenouse 'forcing' would produce a warming of

47 K. But the Earth's temperature would 'only' be

30 (33 may be more accurate) K cooler without any greenhouse effect. Does this mean climate sensitivity without feedbacks is only 0.2 K/(W/m2) ? Probably not, climate sensitivity doesn't have to be independent of temperature, etc. There are other complexities one could point out - that removing all greenhouse effects would cause the Earth to ice over, so the actual temperature difference would be significantly larger than 33 K, that clouds also have an albedo effect and removing cloud greenhouse effect would also cause warming from the reduced albedo (before freezing over), etc, but that doesn't apply to the comparison above because the 155 W/m2 figure is only greenhouse 'forcing' and the 30 or 33 K figure only includes the greenhouse 'forcing' effect with albedo held constant. With feedbacks, a likely value of climate sensitivity is somewhere near 0.7 K/(W/m2). Remember from: http://blogs.abcnews.com/scienceandsociety/2008/07/tropical-storm.html my comment at "Jul 16, 2008 12:34:05 AM" From: http://www.columbia.edu/

jeh1/keeling_talk_and_slides.pdf -------- "Keeling_20051206" "Is There Still Time to Avoid ‘Dangerous Anthropogenic Interference’ with Global Climate?*# A Tribute to Charles David Keeling James E. Hansen NASA Goddard Institute for Space Studies, and Columbia University Earth Institute New York, NY 10025 December 6, 2005" Particularly interesting is the Climate sensitivity section, and in that, the ice age radiative forcings (which include ice albedo as well as greenhouse gas changes and other things), from which a climate sensitivity of 3/4 +/- 1/4 deg C per W/m2 forcing - (in this case the ice albedo, greenhouse gases, etc, are all put in as forcings for the sake of the calculation - Hansen is not implying that they were not feedbacks to other changes on a long time scale, the remaining feedbacks would include water vapor, clouds, etc.) - this is about what is suggested by computer climate models, though the later have some greater uncertainty. ------------- . Specifically, from above source: ice sheets and vegetation albedo: -3.5 +/- 1 W/m2 greenhouse gases: -2.6 +/- 0.5 W/m2 aerosols: -0.5 +/- 1 W/m2 Total -6.6 +/- 1.5 W/m2 Change in temperature: -5 +/- 1 K Implied climate sensitivity: 3/4 +/- 1/4 K/(W/m2) For more on total radiative budgets (including the 155 W/m2 LW forcing): "Earth's Annual Global Mean Energy Budget" J. T. Kiehl and Kevin E. Trenberth


Convince me that so called "Global Warming " is a bad thing!

Dam, you caught me.
About those Dinosars, you know, I just missed that whole apposable thumb thing.

I thought, for awhile, I was doing a little better with you guys but not so much now.

Maybe I'll try common sense and logic next time.

Yeah that's it. Common sense and logic is going to be the new mantra.

Don't worry. I'm not letting the planet die. Need somewhere to put my mountain.

As far as I know the inhabitants of a few micocosms have thought the same thing. they're exitinct now. try again. Throughout history the more complex the organism the higher chances of extinction.

Let me throw out three quick reasons climate change is going to be bad, some of which were hinted at previously above:

Ecosystem disruptions. Much of humanity raises livestock or harvests the oceans in a way that's predicated on the existence of a functional food chain beneath what we eat. Climate change is likely to kill that, ocean acidification pretty much certainly will.

Loss/replacement of infrastructure. We put our dams, farms and cities in places with access to water supplies. We have invested incalculable amounts of money in places like NYC, London, etc. With rising ocean levels and changed precipitation, all that infrastructure is gone or useless.

Human migration. The two prior items, along with rising ocean levels more generally, are going to create human migrations on an unprecedented scale.

Now, any one of these is pretty bad, the combination of all three occurring at once could be tragically expensive, both in human misery and in a strictly economic sense.

Doing nothing is all the more stupid when you consider that there's probably less than a hundred years' supply of a finite resource, meaning we'll have to consider all the same changes we're considering now in a few decades anyway.

What changes can I do that would make a gdamn bit of difference? The answer is nothing. Furthermore, living in a fantasy world where the other 5.whatever billion people all at once decide to make the same changes is just an exercise in futility. It isn't going to happen. Does it make people feel better that they are doing "their part" in a futile action?

Originally posted by Crolis:
I don't see us getting annihilated due to global warming. Talk about pessimism.

At the end of the day though, I simply don't care that much about global warming. I've long ago accepted global warming whether natural or man-made as inevitable and thus we should spend money to prepare for the fallout as opposed to spending ridiculous amounts of time and money trying to convince people that have no intention of listening including emerging world powers that are getting to where they are by polluting.

Don't get me wrong, I am all for modernizing industry when new technology becomes available. I am all for taking steps to limit pollution where reasonable. I am all for R&D to make cars more efficient. All that kinda shit is ok by me. I just am not going to get all that excited or anxious like everyone seems to be trying to get out of people over the issue these days. Just today, my company celebrated earth day with stupid shit like wear a green shirt and you can wear jeans to work. Either do something that actually matters or stfu about it.

Assuming your second 2 paragraphs are intended to support your first, and not just complete non-sequiturs, you seem to be saying that global warming must not be a bad thing because there's nothing we can do to stop it either way. Is that really your reasoning?

No, they are just complete non-sequiturs or rather just separate thoughts from the first sentence which was a response to the post above mine. But no, the second two paragraphs have no relation to the first.

I'm not arguing that current climate trends are good or bad, I'm mostly just skeptical that:
We know how climate is changing
We know why climate is changing, including the possibility that human activity caused it
We know what affect the changes will have on humans and other species

We don't need climate changes as a motivation for reducing dependence on carbonaceous fuels, we've got lots of other factors pushing us in that direction anyway.

Krakatoa changed the global climate by less than 2 degrees, for roughly 5 years (then it went back to the way it was before). If we can hold global warming to that degree (pun!), it will be a smashing success. When people say that global warming is a threat, they mean on the order of 5 times that change, indefinitely (not just for 5 years). The accuracy or not of predictions that our activities will result in that kind of change. aren't really relevant to this thread.

What changes can I do that would make a gdamn bit of difference? The answer is nothing. Furthermore, living in a fantasy world where the other 5.whatever billion people all at once decide to make the same changes is just an exercise in futility. It isn't going to happen. Does it make people feel better that they are doing "their part" in a futile action?

Well, i was at Yale University when it announced last week that it dropped its carbon output by 17% in the last two years, and is on track for an equal reduction in the next 3. It expects that it'll clear 50% within about 15 additional years, all for a cost of about 1.5% of its annual expenditures, that figure drops if fuel prices continue to rise and/or some form of carbon tax gets enacted.

Yale in some ways typifies a large, infrastructure heavy organization, and in others it doesn't - it can dictate energy use in its dorm rooms to an extent a company can't. Still, it does seem to fit most reasonable definitions of a "gdam bit of difference."

Getting more people on board isn't a matter of fantasy, it's a matter of accounting. Make the cost of emitting carbon reflect the true global cost, and a lot more organizations follow Yale's example. Which brings economies of scale that drop costs, etc.

Anyway, question for you: is your macho posturing on the topic supposed to make me feel bad about taking public transit and not heating the apartment much?

Originally posted by Crolis:

Either way it matters not because climate change is going to happen whether you or I like it or not so be prepared to go extinct if that is what you think is going to happen.

Fundementally, we THINK we know what is going on. Realistically I am not sure. Since the founding of Earthday in 1969, 'big science' has made numerous proclamations.

1. Global famine will kill 4 BILLION people on the planet. (early 70's)

2. Global cooling will cause an ice-age. (mid 70's)

3. Global warming is going to happen. (1980's on)

I don't see why the current 'scientific consensus' on global warming is any better prediction than the previous two. All of them were backed by UN studies and scientific papers.

I am excited about green technology, as I feel that it is one of the few things that the US can do better than anyone else (on a large scale). It could be the economic engine of this century.

What I don't like are people calling for limiting my activities based on psuedo-science that changes like the wind blows.

The climate is complicated. It IS NOT well understood. We can make guesses and predicitions, but as the lack of warming recently proves, they are about as accurate as predicting the weather in Seattle 7 days out.

They might be right, but its only by luck.

Not at all. I wish we had public transit around here and I wish it wasn't so fucking hot that I had to always have the AC on. But thems the breaks.

So basically tax energy even more than it already is? I can see maybe 10% of the US getting on board with that not to mention other countries. I would securely put that in the realm of fantasy. Especially considering all the proposals around to remove some of the taxes associated with energy to RELIEVE consumers now which is pretty much the opposite of what you are talking about.

Well, let me just say stay tuned - my coverage of the Yale meeting isn't done yet.

Anyway, even McCain, despite his brainfart on gas taxes, is on board with a cap and trade system. It's effectively a progressive carbon tax, but doesn't use the word "tax", and is associated with the past success with acid rain, and adds the feel-good vibe of market-driven solutions to the cap problem for those who swing that way. You can spin that in a way to drag nearly everyone except the libertarians to the table.

EDIT: We could also accomplish partial solutions by cutting subsidies for domestic extraction, and charging reasonable fees for extraction on federal lands. These also aren't taxes, but change the cost issue.

Hum. Do you think ostriches will go extinct when the climate changes too much?

Originally posted by Crolis:

Either way it matters not because climate change is going to happen whether you or I like it or not so be prepared to go extinct if that is what you think is going to happen.

Fundementally, we THINK we know what is going on. Realistically I am not sure. Since the founding of Earthday in 1969, 'big science' has made numerous proclamations.

1. Global famine will kill 4 BILLION people on the planet. (early 70's)

2. Global cooling will cause an ice-age. (mid 70's)

3. Global warming is going to happen. (1980's on)

I don't see why the current 'scientific consensus' on global warming is any better prediction than the previous two. All of them were backed by UN studies and scientific papers.

I am excited about green technology, as I feel that it is one of the few things that the US can do better than anyone else (on a large scale). It could be the economic engine of this century.

What I don't like are people calling for limiting my activities based on psuedo-science that changes like the wind blows.

The climate is complicated. It IS NOT well understood. We can make guesses and predicitions, but as the lack of warming recently proves, they are about as accurate as predicting the weather in Seattle 7 days out.

They might be right, but its only by luck.

Your above scenarios are somewhat correct but for one major difference with GW. GW is currently happening. Is currently measurable and the effects observable. None of the others you posted are/were at the time . I guess the problem with skeptics such as yourself is not knowing when to admit this stuff in beyond speculation.

Unfortunately the observable effects aren't what people like to always bring up but the OMG dire predictions which amounts to pure speculation.

The numerous scientific papers in the 1970's stated that global cooling was happening and was measurable. This followed three decades of dropping temperatures.

Then the climate started warming and did so for about 30 years. Now the climate seems to have halted its increases or even decreased temperatures a bit in the last couple of years.

Just saying, its not all so 100% locked-up. We don't understand enough to confidently make a prediction that matters. Taking action on the wrong prediction can certainly cause more harm than good. I'd like people to take a look at that possibility before jumping to the conclusion that we need to start burying our CO2 and limiting families from having more than 2 children for the sake of the planet (two wild ideas I've recently heard mentioned).

The numerous scientific papers in the 1970's stated that global cooling was happening and was measurable. This followed three decades of dropping temperatures.

WikiPedia has a list of references that demonstrate the state of confusion about climate change.

WikiPedia has a list of references that demonstrate the state of confusion about climate change.

I'm a huge fan of cheap, clean renewable energy.

As for the debate on global warming, and specifically man's impact on it. I'm still on the fence. While I believe that mankind is capable of messing things up royally by action or inaction, I believe that nature i, by and large, more capable than man.

What do you mean the other two effects were not measurable? Those scenarios were not invented at random. The Malthusian Fantasy was received wisdom in the early 70s. And there were some bad winters in the mid to late 70s. *This* one was a doozy in many parts of N. America too.

Just because those scientists were hippie freaks listening to John Denver on the car 8-track, doesn't mean the current group is any smarter. After all, they might be modafinil popping Celine Dion fanatics.

I suspect any brand new post-doc attempting to invalidate the hockey stick graph is committing career suicide.

I can't understand the recurring theme in this thread of personification of nature. Why is nature given an intelligence, a will and a fickle mind by so many people? Did they watch too much Captain Planet as children?

See, here's the funny thing, one that people engaging in this debate really don't get about science: you could go gathering evidence with the intent of supporting the consensus, and still kill it. The data does the invalidating, people don't. This feeds into the whole "contrarians can't get funding" argument. All they need to do is say they're gathering data that will inform us about climate change. The same class of data could support or invalidate the consensus - we won't know until we gather it.

Really, these sorts of arguments display a fundamental misunderstanding of how science operates.

Mother Nature? It's not really a new concept or anything.

This for me sums up the sad reality of this issue. Climate change is a major front in the culture war. So many people don't want to accept that climate change is really happening and is strongly influenced by human behaviour because that's what "they" "believe," "they" being, as this poster illustrated, hippies/liberals/intellectuals/academics/etc.

Unscrupulous politicians, religious leaders and industry insiders muddy the waters to squeak out a few billion $ more before we're well and truly fucked, and then they're going to leave it to "the market" (IOW, them) to sell us a solution. Sell it to us at full retail value, no less. -- View image here: http://episteme.arstechnica.com/groupee_common/emoticons/icon_frown.gif --

Honestly, I think it's a lot of things.

People resent it when attempts are made shock or frighten them into a course of action or an agenda. When something like The Day After Tomorrow is released, then roundly debunked, it shakes peoples faith that any of it's real. Likewise when stuff like Katrina or global food prices are blamed on global warming. Really?

The consequences are still abstract. Billions are going to be displaced? Manhattan will be flooded? When? How?

There's no plan. Kyoto? Please. People say "you have to start somewhere" but that's just nonsense, what you have to do is start somewhere effective. Global warming is as much about the conflict between the first world and the third world as anything else. The third world wants to live like the first world except oops, there just isn't enough to go around. If you want to talk about inconvienient truths, let's start there.

No. doing nothing but hand waving to stifle any real action while industrial countries continue to increase carbon levels, continue to do what they've always done is nonsense.

What we need is a Manhattan Project type of urgency here. something that reflects the real problems we are facing. History shows that those technologies/economies/industries that are well dug in have the major advantage with respects to government leverage and policy. We need a sea change here..

1) "Extinction" of the human race is total nonsense. Technology will protect some people, and some geographic locations will actually be better off with global warming.

2) Worldwide famine, wars for land and water, fucked up economy, those are possible. When the "system" gets unbalanced and most efforts are made just to preserve the quality of life / survive for some regions, millions/ billions? are bound to die. Maybe not a bad thing, but one way or the other there will be global suffering, just maybe not in Vancouver.

Some people will be really fucked up.

Ex: In asia, hundreds and hundreds of millions of people get their drinkable / farming water from the 7 or 8 major rivers that flow down from the Himalaya glaciers.

The glaciers are quickly melting, pessimists predict they'll be gone by 2015, optimists add a few decades. The point is, when it gets dry, a LOT of people are going to be in deep shit, and start looking for water elsewhere (ie: war etc).

2) With enough ecosystem disturbance, stuff we take for granted will take huge amounts of efforts and energy. Fish populations have already dropped a huge amount (partly due to over-fishing, but drastic and rapid sea temperature and conditions have been measured and linked). It's possible it will get so low we will have to land-farm most of our fish in not too long, using a lot of energy and ressources, OR produce more animal-meat to compensate, using more land and ressources and water, said land maybe needed to be use for vegetables and fruits instead since some other lands are now unusable, etc. And anyway, a lot of fishes are getting dangerously high in the heavy metals department. When they'll be 10x more toxic, they'll die anyway, and I personally won't eat the survivors.

In brief, we'll spend a LOT of time just fixing the mess. That will impact the fundamental way we perceive economy (annual growth will become annual shrinking), affecting banks, industry etc.

3) A problem as important if not more, and often overlooked, is environmental POLLUTION. Species are also dying because of that, and humans are suffering. Recent studies show that on the average european kid, you can detect 100+ toxins (industrial waste, dioxin, mercury, lead, cadmium, various hydrocarbure rejects, various pesticides and insecticides etc), some at dangerous levels (for the 5% or so we HAVE studied, the 95% remaining we'll have the surprise!). The human body just wasn't made to process and eliminate benzene, polychlorinated dibenzodioxins and atrazine. Women are already contaminating their children with teflon and heavy metals with breastmilk. Toxins in a 1 week old brain and nervous system? Awesome.

It doesn't help that most people are in denial of this situation, think the human body is "not affected" or will "clean the stuff out", and not enough scientific studies are made on this depressing problem.

The situation is only going to get worst, as the food chain gets contaminated more and more like it has been, steadily, for decades. When your body hosts hundreds of contaminants, with levels rising, one day you reach a critical point where global health is affected in a systematic way. We already feel the effects: rising, alarming cancer rates are not only due to stress and eating McFries. When birth defects, mental problems, deformations and cancer rates will reach critical levels, a lot of energy and technology will be used just to detox our bodies.

And even if the "upper" countries get super clean (which they won't), China and India are going through industrial revolution with 5-10x our population. Pollution and health concerns are rising a lot in china, and most of that crap comes here in the food chain, air or water. Great!

1) Extinction, no way, but epidemies, wars, famines, war for water and land, are very possible.
2) Our current "system" will be very disturbed, economic growth will be tough since we'll spend a lot of energy just fixing the mess. When things just don't come our way anymore (fish, land, water) and we have to create them at huge cost, it will get tough and boring.

* It doesn't help that the population in our countries is getting older, and in 20-30 years a lot of effort of the diminishing active population will go to take care of our elders, and the rest will be just to fix things up, deal with possible wars and see the economy crash, all that in a global pessimistic mood, which will cause depression and mental problems in a portion of the population and general crapiness.

3) Global warming is only one problem.

Mass-scale contamination from hundreds of toxins is catching up on us, and will reach a critical point at some day.


August

Residents gathered at the Burton Complex, an event center in Lake Charles, Louisiana, for assistance with evacuation. Photo: William Widmer, New York Times.

August 2020 saw media coverage of climate change or global warming increase slightly from the previous month, up 3% across 120 sources in 54 countries in newspaper, radio and television accounts. However, coverage was 45% lower than August 2019 continuing a downward trend in media portrayals of climate change that the Media and Climate Change Observatory (MeCCO) has documented beginning February 2020 when the global COVID-19 pandemic began to dominate public attention.


Watch the video: Why humans are so bad at thinking about climate change


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