The Copenhagen Accord fell far short of expectations heading into the talks. And its backers acknowledge that the national emissions pledges won’t meet the accord’s goal of keeping global temperature increases below 2 degrees Celsius. That’s the level many scientists call needed to avert the most catastrophic climatic changes.
But the Peterson Institute paper finds that the Copenhagen deal isn’t all that bad a start to meeting the 2 degree threshold, which will ultimately depend on what countries do after 2020.
Author Trevor Houser looks at emissions increases under “business as usual” projections, which means no new emissions-cutting policies enacted beyond what was in place in mid-2009. Under that scenario, global greenhouse emissions soar from 45 billion tons in 2005 to 56 billion tons in 2020 and 113 billion tons by 2100, launching temperatures more than 4 degrees higher.
But if countries follow through on their Copenhagen pledges, 2020 emissions would be between 49.7 billion and 51.5 billion tons, and even a bit lower if $100 billion in international climate financing the accord calls for materializes.
The paper cites a recent analysis that found a global emissions peak by 2020 of 40-48 billion tons is needed in order to keep the long-term 2 degree goal in view. Houser then does some “back of the envelope” analysis to see what would have to happen after 2020 given the Copenhagen commitments.
The conclusion? A lot would have to go right, but Houser notes that the Copenhagen deal at least keeps the temperature goal in play, writing that “if countries follow through on their pledges and follow on with more aggressive action, it looks like keeping global temperature increases below 2 degrees Celsius is still within reach.”
“Of course, the more countries ratchet up mid-term action, the better the chances get,” he adds.