CO2 Emissions Are Rising. Or Falling. Actually, It’s Both.
This week in Nature Geoscience, a cadre of scientists going by the name Global Carbon Project will publish a meta-analysis of global carbon emissions. The study led to headlines like, “Global CO2 emissions to drop 2.8 pct in ‘09: report,” and many others more in the ominous vein of “Earth ‘heading for 6C (6 degrees Celsius)’ of warming.” So how did both headlines come from the same study?
This year’s dip is correct: “In 2009, it is likely that the global financial crisis will cause global emissions to actually fall by a couple of percent,” said Michael Raupach, co-author of the report and co-chair of the Global Carbon Project [Reuters]. But, he says, the carbon cut will be short-lived if the recession ends.
In that case, the researchers say, the world will return to its normal trend. Since 2000 emissions have been rising by an average 3.4 per cent every year, compared to one per cent in the 1990s [The Telegraph]. Overall, worldwide emissions rose by 29 percent from 2000 to 2008, and the scientists put forward that 6 degrees Celsius global warming figure as a worst-case scenario—what could happen if the overall rising trend continued unabated.
The timing of their warning seems clear. This week President Obama and Chinese President Hu Jintao talked climate during their meeting in China, with the world climate summit looming. The two committed their countries — the biggest emitters of the heat-trapping gases causing global warming — to backing a detailed political agreement at next month’s climate-change conference in Copenhagen. In their formula, rich countries would commit to reduction targets while developing ones would agree to meet softer goals that would be monitored [MSNBC].
The most troubling assertion of the Global Carbon Project study, however, might be this: The team believes that carbon sinks – the oceans and plants – are probably absorbing a slightly lower proportion of the carbon dioxide from fossil fuel emissions than they were 50 years ago, although researchers admit that uncertainty about the behaviour of sinks remains high [BBC News].