Global CO2 emissions rising faster than worst-case scenarios

One of the small consolations of the Great Recessions was that global greenhouse-gas emissions had dipped slightly, giving the world a few years’ breathing room to figure out how to tackle global warming. But the Copenhagen climate talks fizzled, the world didn’t take advantage of the lull, and the grace period’s now over. According to new data from the Department of Energy’s Oak Ridge National Lab, global carbon-dioxide emissions just saw their biggest one-year rise, a 6 percent jump in 2010.

The striking thing is that emissions are now rising faster than the worst-case scenarios envisioned by the IPCC in its 2007 report. What would this mean for global warming? The chart on the right, from a 2009 study by MIT’s Joint Program on the Science and Policy of Climate Change, lays out the possibilities. If emissions keep growing at their current pace, then the average prediction from MIT’s modeling is that the world could heat up 5.2°C by 2100. But that’s just the average. There’s a 9 percent chance that global surface temperatures could rise more than 7°C — truly uncharted territory. And as we keep adding carbon-dioxide into the air, the odds that we’ll be able to dodge a drastic rise in temperatures become very, very low.

What would that big of a temperature leap do to the planet? Earlier this year, Climate Progress’s Joe Romm put together an excellent post going through the scientific literature on likely impacts from the IPCC’s worst-case emissions scenario. We’d be facing much higher land temperatures — as much as a 5.5°C (10°F) rise in parts of the United States — plus a six-foot sea-level rise by 2100, along with large species loss, many more extreme weather events, and a big hit to the world’s food supply. Arctic temperatures could rise as much as 11°C (20°F), which would, among other things, speed up the melting of Greenland’s ice sheet.

In any case, you can pick through the Energy Department’s emissions data here. About 41 percent of the carbon increase last year came from China, with 12 percent of the leap coming from the slowly recovering U.S. economy (overall U.S. emissions, however, are still lower than they were before the financial crisis).

Interestingly, as the AP’s Seth Borenstein points out, there does seem to be one small bright spot. The developed countries that ratified the 1997 Kyoto Protocol (not including the United States) have managed to cut their carbon-dioxide emissions and are on pace to meet their goals of an 8 percent cut below 1990 levels. But I’d advise caution here: There’s growing evidence that many European nations have been “outsourcing” their emissions to countries like China, and when those embedded emissions from imports get factored in, Europe doesn’t look quite as virtuous. But that’s another reminder that any attempt to tackle global warming has to be, well, global.