The facts are in. They have been for more than a decade. Science overwhelmingly shows us that global warming is happening, and it's getting worse — fast — because of us.

Who says? The majority of climate scientists throughout the world agree that human activity like fossil fuel combustion and deforestation is the main cause of global warming, and that this warming will continue if greenhouse gas emissions aren't reduced. This idea has been endorsed by at least 30 scientific societies and academies of science, including all the national academies of science of the major industrialized countries. According to the Intergovernmental Panel on Climate Change, a Nobel Prize-winning scientific body tasked by the United Nations with assessing the risk of human-caused climate change, “An increasing body of observations gives a collective picture of a warming world and other changes in the climate system. . . . There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.” Using computer climate models, climatologists have established that the recent trend of an increasing global average air temperature, especially since the mid-20 th century, is unprecedented and unnatural. And it's harming life.

Still, there are those who reject the science. A network composed largely of corporate lobbyists, front groups and free-market organizations whose immediate economic interests favor warming-causing fossil-fuel industries insist — despite all the evidence to the contrary — that current climate change hasn't been “proven” to be mainly caused by humans. These “global warming deniers” are funded in large part by Exxon Mobil and other entities that oppose the regulation of global warming pollution.

From the beginning of his administration, oil man former President George W. Bush consistently appointed former lobbyists, executives and others from the fossil fuel industry to key decision-making posts within the federal government. The result was the suppression of important scientific findings on global warming, creating a huge impediment not only to passing measures to help fight global warming but even to simply acknowledging its impacts. Many leading researchers, including NASA's top climate scientist Dr. James Hansen, cite enormous political pressure from political appointees to downplay or even change the results of their scientific research. And in 2007, even after acknowledging that the polar bear deserves federal protection due to global warming, the administration put a gag order on government scientists traveling abroad to prevent discussion of climate change, Arctic sea ice and polar bears.

The Center had substantial success in compelling the Bush administration to acknowledge the science and impacts of global warming. Our long-running battle to protect the polar bear under the Endangered Species Act due to global warming, along with petitions and lawsuits for the protection of numerous other warming-threatened species, forced the administration to acknowledge that climate change is already posing a threat to life on Earth. We also had great success in enforcing the Global Change Resource Act to compel the administration's long-suppressed release of the National Assessment, a comprehensive summary of global warming-caused changes to our country's environment, economy and human health and safety. In fact, all the Center's work to fight global warming — from petitioning and litigating for warming-threatened species to enforcing key laws like the California Environmental Quality Act to opposing too-low national fuel economy standards — have played an enormous role in putting climate change on the political map, making it that much harder for those who would deny it to suppress the truth.

Going forward, we'll continue to press for all government agencies to use the best available science in all decision-making, as well as for restoration of the openness, transparency and integrity in science that should be the hallmark of our federal agencies.

American pika image © Larry Master,