The Global Warming Hype

[Infinite Grey]

At first this topic will appear to belong in Real Science, but the intent is to discuss the political and personal opinions regarding the subject matter, Global Warming.

Over the past decade perhaps longer; global warming has been a bit of a contraversal topic; recently on this forum there have been a few threads devoted to this, and in each case there has been a variety of opinions expressed. Ranging from support of the popular theory to condemnation of of; for a range of reasons - some are valid, others illustrate an acute misunderstanding of how the majority of scientists working the fields of Climate Change arrived to the idea that the most likely cause of global warming is the development of industry. So boys and girls, here is the evidence involved with the theory of Global Warming.

The global average air temperature near the Earth's surface rose 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the hundred years ending in 2005.

"most of the observed increase in globally averaged temperatures since the mid-twentieth century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations" ~ IPCC

Natural phenomena such as solar variation combined with volcanoes probably had a small warming effect from pre-industrial times to 1950 and a small cooling effect from 1950 onward.

Human Land Use.
Deforestation:
66% of CO2 emissions over the last 250 years have resulted from burning fossil fuels, 33% have resulted from changes in land use, primarily deforestation. For those that do not know, forests are not just there to look pretty; plant life act's like "air scrubbers" or filters, absorbing carbon dioxide and reducing the levels of greenhouse gases released into the atmosphere. Include the instances of biomass burnings that frequently accompany deforestation and you also get aerosols.

Terrestrial Albedo:
The albedo of an object is the extent to which it diffusely reflects light from the sun. It is therefore a more specific form of the term reflectivity. Albedo is defined as the ratio of diffusely reflected to incident electromagnetic radiation.

Which leads to Radiative force, the warming and cooling of an area.

What does this mean? It means Cities collect heat and warm the surrounding areas - due to the large quantities of cement, metal, glass and asphalt.

Livestock and land use:
70% of all land used for agriculture is used for liverstock, or 30% of non-ice covered land. 18% of anthropogenic greenhouse gas emissions are attributed to livestock and livestock-related activities.

• 9% of global carbon dioxide emissions
• 35-40% of global methane emissions (chiefly due to enteric fermentation and manure)
• 64% of global nitrous oxide emissions, chiefly as a result of fertilizer use

Aerosols:
These little bastards are fun, the villian in so many senerios, small particles or droplets suspended in the atmosphere. They can be responsible for warming AND cooling, but where do they come from? Well here are some the cheif hometowns:

• biomass burning such as slash and burn deforestation. Aerosols produced are primarily black carbon.
• industrial air pollution, which produces soot and airborne sulfates, nitrates, and ammonium
• dust produced by land use effects such as desertification

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"Anthropogenic warming of the climate system is widespread and can be detected in temperature observations taken at the surface, in the free atmosphere and in the oceans. Evidence of the effect of external influences, both anthropogenic and natural, on the climate system has continued to accumulate since the TAR [Third Assessment Report]."

There are external and internal phenomena, such as solar variations and volcanic activity; but the evidence suggests that human activity is responsible for the majority of the greenhouse effect.

Evidence for this conclusion includes:

• Estimates of internal variability from climate models, and reconstructions of past temperatures, indicate that the warming is unlikely to be entirely natural.
• Climate models forced by natural factors and increased greenhouse gases and aerosols reproduce the observed global temperature changes; those forced by natural factors alone do not.
• "Fingerprint" methods indicate that the pattern of change is closer to that expected from greenhouse gas-forced change than from natural change.
• The plateau in warming from the 1940s to 1960s can be attributed largely to sulphate aerosol cooling

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THIS BIT IS IMPORTANT
Detection vs. attribution:

Detection of a signal requires demonstrating that an observed change is statistically significantly different from that which can be explained by natural internal variability.

Attribution requires demonstrating that a signal is:

• unlikely to be due entirely to internal variability;
• consistent with the estimated responses to the given combination of anthropogenic and natural forcing
• not consistent with alternative, physically plausible explanations of recent climate change that exclude important elements of the given combination of forcings.

Detection does not imply attribution, and is easier than attribution. Unequivocal attribution would require controlled experiments with multiple copies of the climate system, which is not possible. Attribution, as described above, can therefore only be done within some margin of error. For example, the IPCC's Fourth Assessment Report says "it is extremely likely that human activities have exerted a substantial net warming influence on climate since 1750," where "extremely likely" indicates a probability greater than 95%.

Following the publication of the Third Assessment Report (TAR) in 2001, "detection and attribution" of climate change has remained an active area of research. Some important results include:

• A review of detection and attribution studies by the International Ad Hoc Detection and Attribution Group[9] found that "natural drivers such as solar variability and volcanic activity are at most partially responsible for the large-scale temperature changes observed over the past century, and that a large fraction of the warming over the last 50 yr can be attributed to greenhouse gas increases. Thus, the recent research supports and strengthens the IPCC Third Assessment Report conclusion that 'most of the global warming over the past 50 years is likely due to the increase in greenhouse gases.'"
• Multiple independent reconstructions of the temperature record of the past 1000 years confirm that the late 20th century is probably the warmest period in that time
• Two papers in Science in August 2005 resolve the problem, evident at the time of the TAR, of tropospheric temperature trends. The UAH version of the record contained errors, and there is evidence of spurious cooling trends in the radiosonde record, particularly in the tropics. See satellite temperature measurements for details; and the 2006 US CCSP report.

• Barnett and colleagues say that the observed warming of the oceans "cannot be explained by natural internal climate variability or solar and volcanic forcing, but is well simulated by two anthropogenically forced climate models," concluding that "it is of human origin, a conclusion robust to observational sampling and model differences"
• Bratcher and Giese observed conditions that "could be an indication of a climate regime shift to pre-1976 conditions." Bratcher and Giese conclude: "The results presented here do not preclude the possibility that anthropogenic sources of greenhouse gases have contributed to global warming. However the results do indicate that the human forced portion of global warming may be less than previously described."

Ice Core Records:
Ice core record shows that on some occasions temperature starts rising hundreds of years before CO2 increases. Such results confirm that the relationship between CO2 and climate can go in both directions: changes in CO2 concentrations affect climate, while changes in climate can affect CO2 concentrations.

They indicate that he earth had gone through many climate changes over its history, as result of a few natural factors; solar activity, change in orbit, volcanic activity and so on.

But the point is, that since the beginning of the industrial age, CO2 levels greatly exceed the range found in the ice core data. Isotopic analysis of atmospheric CO2 confirms that fossil fuel burning is the source of most of the CO2 increase, unlike during prior interglacial periods.

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Reference:

1. Working Group I: The Physical Basis for Climate Change. IPCC.
2. (2007) Working Group I: The Physical Basis for Climate Change (Summary for Policymakers). IPCC.
3. The Kyoto Protocol. UNFCCC.
4. (2007) Working Group I: The Physical Basis for Climate Change (Technical summary). IPCC.
5. a b c (2006) Livestock's Long Shadow. Food and Agricultural Organization of the U.N.
6. (2007) Working Group I: The Physical Basis for Climate Change (Front matter). IPCC.
7. Geerts, B.. Aerosols and Climate.
8. (2001) Working Group I: The Physical Basis for Climate Change (Summary for Policymakers). IPCC
9. Barnett, T.; et al. (May 2005). "Detecting and Attributing External Influences on the Climate System: A Review of Recent Advances". Journal of Climate
10. gavin (2007-08-11). Et Tu LT?. RealClimate.org.
11. gavin (2007-08-11). The tropical lapse rate quandary. RealClimate.org.
12. Wigley, Tom M. L.; et al. (2006-05-02). "Temperature Trends in the Lower Atmosphere - Understanding and Reconciling Differences (Executive Summary)". NOAA.
13. Barnett, Tim P.; et al. (2005-07-08). "Penetration of Human-Induced Warming into the World's Oceans".
14. Bratcher, Amy J.; Giese, Benjamin S. (2002-10-08). "Tropical Pacific Decadal Variability and Global Warming"
15. Geophysical Research Letters.
16. Lindzen, Richard S. (1997-08-05). "Can increasing carbon dioxide cause climate change?". Proceedings of the National Academy of Sciences
17. Indermühle, Andreas; Monnin, Eric; Stauffer, Bernhard; Stocker, Thomas F.; Wahlen, Martin (2000). "Atmospheric CO2 concentration from 60 to 20 kyr BP from the Taylor Dome ice core, Antarctica". Geophysical Research Letters 27.
18. Fischer, Hubertus; Wahlen, Martin; Smith, Jesse; Mastroianni, Derek; Deck, Bruce (1999). "Ice core records of atmospheric CO2 around the last three glacial terminations".
19. Skinner, L.C. (2006). "Glacial – interglacial atmospheric CO2 change: a simple “hypsometric effect” on deep-ocean carbon sequestration?". Climate of the Past Discussions 2.
20. Paillard, Didier (2000). "Glacial Cycles: Toward a New Paradigm". Reviews of Geophysics
21. Liou, K.N. (2002). An Introduction to Atmospheric Radiation (2nd ed). Academic Press.
22. Staley, D.O.; G.M. Jurica (1970). "Flux emissivity tables for water vapor, carbon dioxide and ozone". Journal of Applied Meteorology

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So, why do people believe that scientists just make this stuff up? What could there agenda possibly be? There is little money in cutting down on greenhouse gas emissions, and little thanks for possibly heralding the end of the world as we know it.

The bigger question I have to wonder, is why some people are so hell bent on insisting that nothing is wrong and our pollution isn't doing this. Is it personal?

[Brightshores]

Wow, great post.

Originally Posted by Infinite Grey

So, why do people believe that scientists just make this stuff up? What could there agenda possibly be? There is little money in cutting down on greenhouse gas emissions, and little thanks for possibly heralding the end of the world as we know it.

The bigger question I have to wonder, is why some people are so hell bent on insisting that nothing is wrong and our pollution isn't doing this. Is it personal?

Well - admitting that our pollution is doing this is tantamount to accepting personal responsibility for all of this. People in this day and age aren't generally into accepting responsibility and the attendant need to do something about it. It's a guilt thing, I think - if global warming doesn't exist or is a natural phenomenon, then nobody needs to feel guilty about it or worry about fixing it.

Denying global warming also is a nice guilt-free way for people to cheerfully drive enormous SUV's, leave the lights on, buy enormous amounts of things they don't need, and throw out huge amounts of crap into the environment without worrying about it. Many people are comfortable in the consumerist lifestyle - they simply don't want to change or give up the trappings of overconsumption.

[Nox_Mortus]

well a lot of people tend to dismiss it on more or less ideological reasons, they don't think industry should be regulated so they dismiss the need to regulate it. Or they don't really care about regulation but don't think businesses should have to spend money on it. Also it doesn't help that people like Al Gore make this whole thing over sensationalized which causes people to think that Global Warming is just a political trick to get people to vote a certain way.

[Belgalad]

Because if humans caused it, then they'd have to put down the keys to their hummers or else feel guilty about contributing to the End Of The World As We Know It.

That's why the opposition side has morphed since about 1990 from "No such thing!" to "Maybe, but even if does exist, it's insignificant and will affect nothing!" to "Ok, it exists, and it might be big, but it's not our fault!"

[Belgalad]

And, as an afterthought, may I copy that post with proper attribution onto my blog? I've been trying to find a concise, reference-filled global warming prior for a a few weeks now.

[Infinite Grey]

Originally Posted by Belgalad

And, as an afterthought, may I copy that post with proper attribution onto my blog? I've been trying to find a concise, reference-filled global warming prior for a a few weeks now.

I wouldn't call my post concise, go ahead and use it.

[Sequoia]

I would say that some of us remain convinced that there is MORE to global warming than CO2 emissions. There have been times in earth's history that it was MUCH warmer than it is today, as little as two thousand years ago.

And I don't think ANYONE is arguing that pollution is a good thing.

I recycle. I don't leave lights on. I certainly don't drive an SUV. And I completely oppose coal-burning plants, which contribute probably the majority of CO2. I support hybrid vehicles, and will support a reasonable alternative fuel source such as CNG (not crackpot scams like ethanol and hydrogen).

It's just that some of us don't believe that our pollution is the only thing causing the earth to warm. And I don't think that's an unreasonable position.

[Infinite Grey]

Originally Posted by Sequoia

I would say that some of us remain convinced that there is MORE to global warming than CO2 emissions. There have been times in earth's history that it was MUCH warmer than it is today, as little as two thousand years ago.

And I don't think ANYONE is arguing that pollution is a good thing.

I recycle. I don't leave lights on. I certainly don't drive an SUV. And I completely oppose coal-burning plants, which contribute probably the majority of CO2. I support hybrid vehicles, and will support a reasonable alternative fuel source such as CNG (not crackpot scams like ethanol and hydrogen).

It's just that some of us don't believe that our pollution is the only thing causing the earth to warm. And I don't think that's an unreasonable position.

No one with clue every said CO2 was the only cause, just likely the major cause.

[WokeUpDead]

Reality has a liberal bias.

[Philosophia]

Well said.