By comparison, global carbon levels averaged a yearly rise of just under 2 parts per million from 2000 to 2010, and increased by less than 1 part per million in the 1960s. The 2012 rise makes it that much more unlikely that global warming can be limited to the 2 degree Celsius threshold most scientist agree is the bare minimum necessary to avoid truly catastrophic levels of climate change. The Associated Press has the report:
Carbon dioxide levels jumped by 2.67 parts per million since 2011 to total just under 395 parts per million, says Pieter Tans, who leads the greenhouse gas measurement team for the National Oceanic and Atmospheric Administration.
That’s the second highest rise in carbon emissions since record-keeping began in 1959. The measurements are taken from air samples captured away from civilization near a volcano in Mauna Loa, Hawaii.
More coal-burning power plants, especially in the developing world, are the main reason emissions keep going up – even as they have declined in the U.S. and other places, in part through conservation and cleaner energy.
At the same time, plants and the world’s oceans which normally absorb some carbon dioxide, last year took in less than they do on average, says John Reilly, co-director of Joint Program on the Science and Policy of Global Change. Plant and ocean absorption of carbon varies naturally year to year.
There is a limited “budget” of carbon the world can dump into the atmosphere while still maintaining a reasonable chance of staying under the 2 degree limit: 565 gigatons by 2050 to keep our chances at 75 percent, to be precise. At our current trends — and as 2012′s jump can attest — we’re set to burn through that budget in 16 years, rendering our chances of staying under 2 degrees of warming alarmingly thin. Getting back on track will require keeping the overwhelming majority of the fossil fuel available to us in the ground.
Otherwise, we face destructively high sea level rise, water supplies for hundreds of millions of people threatened by climate shifts, global crop declines, bleached coral reefs around the world, a rise in ocean acidification threatening marine ecosystems, and a host of other crises.