ripple: Global Warming- Science

Global warming has become perhaps the most complicated issue facing world leaders. On the one hand, warnings from the scientific community are becoming louder, as an increasing body of science points to rising dangers from the ongoing buildup of human-related greenhouse gases — produced mainly by the burning of fossil fuels and forests. On the other, the technological, economic and political issues that have to be resolved before a concerted worldwide effort to reduce emissions can begin have gotten no simpler, particularly in the face of a global economic slowdown.

Global talks on climate change opened in Cancún, Mexico, in late 2010 with the toughest issues unresolved, and the conference produced modest agreements. But while the measures adopted in Cancún are likely to have scant near-term impact on the warming of the planet, the international process for dealing with the issue got a significant vote of confidence.

The agreement fell well short of the broad changes scientists say are needed to avoid dangerous climate change in coming decades. But it laid the groundwork for stronger measures in the future, if nations are able to overcome the emotional arguments that have crippled climate change negotiations in recent years. The package, known as the Cancún Agreements, gives the more than 190 countries participating in the conference another year to decide whether to extend the frayed Kyoto Protocol, the 1997 agreement that requires most wealthy nations to trim their emissions while providing assistance to developing countries to pursue a cleaner energy future.

At the heart of the international debate is a momentous tussle between rich and poor countries over who steps up first and who pays most for changed energy menus.

In the United States, on Jan. 2, 2011, the Environmental Protection Agency imposed its first regulations related to greenhouse gas emissions. The immediate effect on utilities, refiners and major manufacturers will be small, with the new rules applying only to those planning to build large new facilities or make major modifications to existing plants. Over the next decade, however, the agency plans to regulate virtually all sources of greenhouse gases, imposing efficiency and emissions requirements on nearly every industry and every region.

President Obama vowed as a candidate that he would put the United States on a path to addressing climate change by reducing emissions of carbon dioxide and other greenhouse gas pollutants. He offered Congress wide latitude to pass climate change legislation, but held in reserve the threat of E.P.A. regulation if it failed to act. The deeply polarized Senate’s refusal to enact climate change legislation essentially called his bluff.

But working through the E.P.A. has guaranteed a clash between the administration and Republicans that carries substantial risks for both sides. The administration is on notice that if it moves too far and too fast in trying to curtail the ubiquitous gases that are heating the planet it risks a Congressional backlash that could set back the effort for years. But the newly muscular Republicans in Congress could also stumble by moving too aggressively to handcuff the Environmental Protection Agency, provoking a popular outcry that they are endangering public health in the service of their well-heeled patrons in industry.