Global Warming & Climate Change
Steen Ulrik Johannessen/Agence France-Presse — Getty Images
Global warming has become perhaps the most complicated issue facing world leaders. 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.
Global emissions of carbon dioxide were at a record high in 2011 and were likely to take a similar jump in 2012, scientists reported in early December 2012 — the latest indication that efforts to limit such emissions are failing.
Over all, global emissions jumped 3 percent in 2011 and are expected to jump another 2.6 percent in 2012, researchers reported.
The new figures show that emissions are falling, slowly, in some of the most advanced countries, including the United States. That apparently reflects a combination of economic weakness, the transfer of some manufacturing to developing countries and conscious efforts to limit emissions, like the renewable power targets that many American states have set. The boom in the natural gas supply from hydraulic fracturing is also a factor, since natural gas is supplanting coal at many power stations, leading to lower emissions.
But the decline of emissions in the developed countries is more than matched by continued growth in developing countries like China and India, the new figures show. Coal, the dirtiest and most carbon-intensive fossil fuel, is growing fastest, with coal-related emissions leaping more than 5 percent in 2011, compared with the previous year.
Emissions continue to grow so rapidly that an international goal of limiting the ultimate warming of the planet to 3.6 degrees, established three years ago, is on the verge of becoming unattainable, said researchers affiliated with the Global Carbon Project, a network of scientists that tracks emissions.
Yet nations around the world, despite a formal treaty pledging to limit warming — and 20 years of negotiations aimed at putting it into effect — have shown little appetite for the kinds of controls required to accomplish that goal.
For almost two decades, the United Nations has sponsored annual global talks, the United Nations Framework Convention on Climate Change, an international treaty signed nearly 200 countries to cooperatively discuss global climate change and its impact. The conferences operate on the principle of consensus, meaning that any of the participating nations can hold up an agreement.
The conflicts and controversies discussed are monotonously familiar: the differing obligations of industrialized and developing nations, the question of who will pay to help poor nations adapt, the urgency of protecting tropical forests and the need to rapidly develop and deploy clean energy technology.
2012 Was Hottest Year Ever in U.S.
In January 2013, the National Climatic Data Center in Asheville, N.C., announced that 2012 was the hottest year ever in the contiguous United States since records began in 1895. The year 2012 brought a blistering March heat wave, a severe drought in the Corn Belt and a massive storm that caused broad devastation in mid-Atlantic states.
The temperature differences between years are usually measured in fractions of a degree, but 2012 blew away the previous record, set in 1998, by a full degree Fahrenheit.
If that does not sound so impressive, consider that 34,008 new daily high records were set at weather stations across the country, compared with only 6,664 new record lows, according to a count maintained by the Weather Channel meteorologist Guy Walton, using federal temperature records.
That ratio, which was roughly in balance as recently as the 1970s, has been out of whack for decades as the country has warmed, but never by as much as it was in 2012.
Scientists said that natural variability almost certainly played a role in last year’s extreme heat and drought. But many of them expressed doubt that such a striking new record would have been set without the backdrop of global warming caused by the human release of greenhouse gases.
Background
Scientists learned long ago that the earth’s climate has powerfully shaped the history of the human species — biologically, culturally and geographically. But only in the last few decades has research revealed that humans can be a powerful influence on the climate, as well.
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