Developing nations are now the world's biggest polluters

The latest report from the United Nations climate change body, released Tuesday, makes clear the good, the bad, and the ugly about one of the world's most intractable problems. As things stand today, the world will be hard pressed to limit greenhouse-gas emissions and avoid the worst effects of global warming during the rest of the century. That's the ugly. In the twenty-odd years since global warming leapt on the international stage at the Earth Summitat Rio de Janiero global greenhouse-gas emissions have not only kept growing, they're growing at an ever-faster clip. That's the bad. Now, the world's hopes for limiting temperature increases and minimizing catastrophes such as rising sea levels and devastating droughts depend to a large extent on what steps developing economies take to fundamentally change the way they use energy. And that, curiously enough, could be the good. On Tuesday, the final, full draftreport from Working Group III of the International Panel on Climate Change came out. (U.N. officials had released tidied up, trimmed down summari esof that latest consensus among climate scientists over the weekend.) The report's purpose is not to dive into all the contentious and sometimes controversial science behind climate change, but rather to lay out what the world can do about it. And in dense, committee-edited prose, the sprawling report makes clear that the world is still headed very much in the wrong direction. "The current trajectory of global annual and cumulative emissions of [greenhouse gases] is inconsistent with widely discussed goals of limiting global warming at 1.5 to 2 degrees Celsius above the pre-industrial level," the report found. "We need to decrease the [carbon dioxide] in the atmosphere, and to do that, we need to bring emissions down dramatically, but right now global emissions are increasing," explained Gernot Wagner, an environmental economist at the Environmental Defense Fund, which advocates market-based solutions for climate change. undefined "This is a freakishl y big problem. " While computer models show that the world could conceivably slash carbon emissions and stabilize temperatures, that would require prompt, unanimous, radical action by nearly all nations. That, to say the least, is unlikely: "The assumptions needed to have a likely chance of limiting warming to 2 degrees are very difficult to satisfy in real world conditions," the report found. That is due, in large part, to the fact that global greenhouse gas emissions just keep rising, despite growing awareness in most countries that pumping more carbon dioxide and other greenhouse gases into the atmosphere leads to rising temperatures. Global emissions rose an average of 2.2 percent per year from 2000 to 2010, up sharply from an annual average growth rate of 1.3 percent from 1970 to 2000. Global emissions keep rising because over the last decade, the center of gravity of the world economy has shifted away from developed, relatively efficient economies such as Europe and the United States toward fast-growing, relatively inefficient economies such as China and India. The problem is compounded, in part, because factories in countries such as China now produce a host of goods for export that rich countries use to make themselves; that means that, in essence, the rich world has outsourc eda portion of its own greenhouse-gas emissions to developing countries. Since the last big UN climate report came out in 2007, developing countries have passed developed countries to become the biggest emitters of greenhouse gases. The global emissions total in 2010 hit 49.5 billion tons of carbon dioxide equivalent (which translates other greenhouse gases such as methane into carbon dioxide), the highest level to date, the report found. That makes it more difficult, and more expensive, to meet climate goals. "If you're trying to stabilize 2 degrees Celsius in this century, then every five years it's going to get more difficult, because the rate of decrease has to be greater and there's already a larger accumulated stock in the atmosphere," said Robert Stavins, a climate-policy expert at Harvard University's Belfer Center and a contributor to the latest IPCC report. Going forward, that means that the developing world will have to bear the brunt of responsibility for curbing emissions, if the world is to come anywhere close to its target of limiting carbon concentrations in the atmosphere to around 450 parts per million (compared with just over 400 parts per million today).