External Sources

• http://www.time.com/time/health/article/0,8599,2096055,00.html
• for: republicas against change

Who's Bankrolling the Climate-Change Deniers?

Not anymore. With the exception of Jon Huntsman — who barely registers in polls — you can't find a Republican presidential candidate who unequivocally believes in climate science, let alone one who wants to do anything about it. Instead of McCain — who has walked back his own climate-policy realism since the 2008 elections — we have Texas Governor Rick Perry, who told voters in New Hampshire over the weekend that "I don't believe manmade global warming is settled in science enough." And many Republicans agree with him: the percentage of self-identified Republicans or conservatives answering yes to the question of whether the effects of global warming were already being felt fell to 30% or less in 2010, down from 50% in 2007-08. Meanwhile, liberals and Democrats remained around 70% or more.

Read more: http://www.time.com/time/health/article/0,8599,2096055,00.html#ixzz1urhWLyHi

• http://environment.nationalgeographic.com/environment/global-warming/gw-causes/

What Causes Global Warming?

Scientists have spent decades figuring out what is causing global warming. They've looked at the natural cycles and events that are known to influence climate. But the amount and pattern of warming that's been measured can't be explained by these factors alone. The only way to explain the pattern is to include the effect of greenhouse gases (GHGs) emitted by humans.

To bring all this information together, the United Nations formed a group of scientists called the Intergovernmental Panel on Climate Change, or IPCC. The IPCC meets every few years to review the latest scientific findings and write a report summarizing all that is known about global warming. Each report represents a consensus, or agreement, among hundreds of leading scientists.

One of the first things scientists learned is that there are several greenhouse gases responsible for warming, and humans emit them in a variety of ways. Most come from the combustion of fossil fuels in cars, factories and electricity production. The gas responsible for the most warming is carbon dioxide, also called CO2. Other contributors include methane released from landfills and agriculture (especially from the digestive systems of grazing animals), nitrous oxide from fertilizers, gases used for refrigeration and industrial processes, and the loss of forests that would otherwise store CO2.

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In order to understand the effects of all the gases together, scientists tend to talk about all greenhouse gases in terms of the equivalent amount of CO2. Since 1990, yearly emissions have gone up by about 6 billion metric tons of "carbon dioxide equivalent" worldwide, more than a 20 percent increase.

• http://www.guardian.co.uk/science/2012/mar/03/michael-mann-climate-change-deniers

Death threats, intimidation and abuse: climate change scientist Michael E. Mann counts the cost of honesty

Mann became a target of climate deniers' hate because his research revealed there has been a recent increase of almost 1°C across the globe, a rise that was unprecedented "during at least the last 1,000 years" and which has been linked to rising emissions of carbon dioxide from cars, factories and power plants. Many other studies have since supported this finding although climate change deniers still reject his conclusions.

Mann's research particularly infuriated deniers after it was used prominently by the UN's Intergovernmental Panel on Climate Change (IPCC) in one of its assessment reports, making him a target of right-wing denial campaigners. But as the 46-year-old scientist told theObserver, he only entered this research field by accident. "I was interested in variations in temperatures of the oceans over the past millennium. But there are no records of these changes so I had to find proxy measures: coral growth, ice cores and tree rings."

By studying these he could trace temperature fluctuations over the past 1,000 years, he realised. The result was a graph that showed small oscillations in temperature over that period until, about 150 years ago, there was a sudden jump, a clear indication that human activities were likely to be involved. A colleague suggested the graph looked like a hockey stick and the name stuck. The results of the study were published in Nature in 1998. Mann's life changed for ever.

"The trouble is that the hockey stick graph become an icon and deniers reckoned if they could smash the icon, the whole concept of global warming would be destroyed with it. Bring down Mike Mann and we can bring down the IPCC, they reckoned. It is a classic technique for the deniers' movement, I have discovered, and I don't mean only those who reject the idea of global warming but those who insist that smoking doesn't cause cancer or that industrial pollution isn't linked to acid rain."

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In addition, Mann has been attacked by Ken Cuccinelli, the Republican attorney general of Virginia who has campaigned to have the scientist stripped of academic credentials. Several committees of inquiry have investigated Mann's work. All have exonerated him.
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 the harassment of scientists by politicians seeking distractions to avoid taking action, and the outright lies being spread about them."

"Words like those give me hope," says Mann.

• http://www.scientificamerican.com/article.cfm?id=science-behind-climate-change

The Physical Science behind Climate Change

For a scientist studying climate change, “eureka” moments are unusually rare. Instead progress is generally made by a painstaking piecing together of evidence from every new temperature measurement, satellite sounding or climate-model experiment. Data get checked and rechecked, ideas tested over and over again. Do the observations fit the predicted changes? Could there be some alternative explanation? Good climate scientists, like all good scientists, want to ensure that the highest standards of proof apply to everything they discover.

And the evidence of change has mounted as climate records have grown longer, as our understanding of the climate system has improved and as climate models have become ever more reliable. Over the past 20 years, evidence that humans are affecting the climate has accumulated inexorably, and with it has come ever greater certainty across the scientific community in the reality of recent climate change and the potential for much greater change in the future. This increased certainty is starkly reflected in the latest report of the Intergovernmental Panel on Climate Change (IPCC), the fourth in a series of assessments of the state of knowledge on the topic, written and reviewed by hundreds of scientists worldwide.

The physical science assessment focuses on four topics: drivers of climate change, changes observed in the climate system, understanding cause-and-effect relationships, and projection of future changes. Important advances in research into all these areas have occurred since the IPCC assessment in 2001. In the pages that follow, we lay out the key findings that document the extent of change and that point to the unavoidable conclusion that human activity is driving it.

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