A new climate analysis by scientists at the Massachusetts Institute of Technology and elsewhere, which focuses on probability outcomes, finds that even moderate reductions in greenhouse gas emissions now will significantly lower the risks of dramatic, future climate change.
The analysis also indicates that, to avoid a temperature increase of more than 2 degrees C (3.6 degrees F.) above preindustrial levels — an oft-discussed goal — these emissions reductions had better come soon. If not, say the researchers, dramatic changes in climate driven by feedback loops will become difficult — and perhaps impossible — to control.
The analysis lays out climate salvation in terms of odds. We still have around a 50-50 chance, it says, of stabilizing climate and avoiding a temperature increase of much more than 2 degrees C. (That's supposed to be encouraging, by the way.) Generally, scientists think that keeping temperature increases to no more than that will avoid dramatic sea level rise, as well as a disruption of agriculture and natural ecosystems.
Here's what needs to happen in order to fall on the right side of that 50-50 odds ratio, say the authors:
In the US, we need to cut emissions at least by the amount laid out in the current versions of the climate bills before Congress. (The House bill aims to cut emissions by 17 percent by 2020; the Senate version by 20 percent in the same period.