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Yes Warming – big threat

Global Warming is an existential threat – empirical evidence proves.

Britt 05 - Managing Editor of LiveScience and Senior Science Writer for (Robert Roy Britt: “Global Warming Likely Cause of Worst Mass Extinction Ever” at: RC)
The new study, reported Thursday in the online version of the journal Science, found no evidence for impacts. It indicates the culprit was probably atmospheric warming linked to greenhouse gases from erupting volcanoes. "Animals and plants both on land and in the sea were dying at the same time, and apparently from the same causes - too much heat and too little oxygen," said University of Washington paleontologist Peter Ward, lead author of the latest paper. It is the second study in less than two months to reach a similar conclusion. Ward and his colleagues examined Permian-Triassic vertebrate fossils, including 126 skulls from reptiles and amphibians. They found evidence for a gradual extinction over about 10 million years leading up to the boundary between the Permian and Triassic periods, then a sharp increase in extinction rate at the boundary that then lasted another 5 million years. That's not what you'd expect from a catastrophic asteroid impact, which theorists say could obliterate a lot of life instantly and set up a global winter that would kill off other species in mere months or years. A search for material expected to be left by an asteroid or comet impact in the same layers of Earth turned up nothing. If there was an impact, it was a relatively minor contributor to the extinction, Ward's team contends. The work provides a glimpse of what can happen when the climate heats up over long periods, Ward said. The evidence for a warming planet back then is pretty solid based on studies of continuous volcanic eruptions in an area known as the Siberian Traps. As the planet warmed, large amounts of frozen methane gas under the ocean might have been released to trigger runaway greenhouse warming, Ward said. "It appears that atmospheric oxygen levels were dropping at this point also," he said. "If that's true, then high and intermediate elevations would have become uninhabitable. More than half the world would have been unlivable." Atmospheric oxygen, now at about 21 percent of the content of air at sea level, dropped to around 16 percent during the Great Dying, evidence suggests. The effect would be like trying to breathe atop a 14,000-foot mountain. "It got hotter and hotter until it reached a critical point and everything died," Ward said. "It was a double-whammy of warmer temperatures and low oxygen, and most life couldn't deal with it." A study out of the University of Vienna, announced in December, also found no evidence for a large space rock collision near the time of the Great Dying.

Yes Warming – big threat

Global warming is real – 99.99% of scientists agree

Baker 7/19/10 (David R. staff writer for the San Francisco Chronicl, Climategate' fallout may impact legislation
"Despite multiple denials from people in the field, this has really hurt," said Daniel Kammen, a UC Berkeley professor who contributes to reports by the Intergovernmental Panel on Climate Change. The accuracy of the IPCC's reports, long considered the most authoritative on global warming, came under fire during Climategate.

"Even though the science of climate change hasn't changed, the public perception of it has," Kammen said. "You have less than 50 percent of people strongly believing in something that 99.99 percent of climate scientists agree on."

Overwhelming ev that climate change is real – fossil fuel emissions

Suzuki 7/19/10 (David, Chair of the David Suzuki Foundation, is an award-winning scientist,Environmentalist, Science deals blow to deluded climate change deniers,
It must be difficult, if not downright embarrassing, to be a climate change denier these days. After all, the scientists they’ve attacked have been exonerated, London’s Sunday Times newspaper ran a retraction and apology for an article deniers were using to discredit climate change science, and more and more denier “experts” are being exposed as shills for industry or just disingenuous clowns. (Naomi Oreskes’s excellent book Merchants of Doubt offers insight into how the deniers operate.) Meanwhile, evidence that fossil fuel emissions contribute to dangerous climate change just keeps building. We use the term deniers deliberately. People who deny overwhelming scientific evidence without providing any compelling evidence of their own and who remain steadfast in their beliefs even as every argument they propose gets shot down do not demonstrate the intellectual rigour to be called skeptics. Mean-while, evidence of the harm our fossil fuel addiction causes beyond climate change mounts every day, as oil spews into the Gulf of Mexico and as industry and governments spend huge sums of money to keep us hooked. Of course, the deniers will ignore the evidence. Nothing would please us more than if they were right. Life really would be easier if fossil fuels like oil and coal did not cause environmental damage or pose risks to life on our small planet. But this is the real world, with real scientific evidence pointing to the urgent need to make changes in the way we live and get energy. We have many ways to confront the threat of catastrophic climate change, from individual efforts to conserve energy and pollute less to government initiatives to encourage research and development into clean energy technology. And then we have the spectacle of the fossil fuel industry and petro-fuelled governments doing all they can to prolong our addiction to nonrenewable and polluting sources of energy as oil continues to gush into the Gulf of Mexico, threatening bird, marine, and human life, as well as local economies.
Warming causes a shift in oxygen levels threatening the existence of the human race

Hoegh-Guldberg 6/19/10 - professor at The University of Queensland and the director of its Global Change Institute, (Hoegh-Guldberg: “Could unbridled climate changes lead to human extinction?” RC)

'We may see sudden, unexpected changes that have serious ramifications for the overall well-being of humans, including the capacity of the planet to support people. This is further evidence that we are well on the way to the next great extinction event,' says Hoegh-Guldberg. 'The findings have enormous implications for mankind, particularly if the trend continues. The earth's ocean, which produces half of the oxygen we breathe and absorbs 30 percent of human-generated carbon dioxide, is equivalent to its heart and lungs. This study shows worrying signs of ill-health. It's as if the earth has been smoking two packs of cigarettes a day!,' he added. 'We are entering a period in which the ocean services upon which humanity depends are undergoing massive change and in some cases beginning to fail', he added. The 'fundamental and comprehensive' changes to marine life identified in the report include rapidly warming and acidifying oceans, changes in water circulation and expansion of dead zones within the ocean depths. These are driving major changes in marine ecosystems: less abundant coral reefs, sea grasses and mangroves (important fish nurseries); fewer, smaller fish; a breakdown in food chains; changes in the distribution of marine life; and more frequent diseases and pests among marine organisms. Study co-author John F. Bruno, associate professor in marine science at The University of North Carolina, says greenhouse gas emissions are modifying many physical and geochemical aspects of the planet's oceans, in ways 'unprecedented in nearly a million years'.

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