Scientists and policymakers have generally settled on 2°C as the amount of global temperature increase, over pre-industrial levels, the climate can take without creating truly dangerous upheavals. Because the effect of carbon in the atmosphere is cumulative, staying below that threshold requires a hard limit on the amount of carbon the world emits between now and 2100. We’ve already blown through a bit over half of that “carbon budget.” Last week’s World Energy Outlook 2014 from the International Energy Agency (IEA) projects that, on our current course, we’ll chew through the rest by 2040.The bottom line is we cease all CO2 emissions by 2040, which won't happen. So 2 degrees Celsius is not going to happen.
While IEA projects that renewables will grow aggressively between now and 2040, overtaking coal as the globe’s leading source of electricity, and that coal and oil use will effectively plateau by that point, fossil fuel use — and thus carbon emissions — will remain about 75 percent of the world’s energy consumption. That, according to IEA, puts us on course for roughly 3.6°C of global warming by 2100.and climbing. It will be rough for our grandchildren dealing with a nearly 4 degree Celsius increase in atmospheric temperatures. It's just my opinion, but I believe they're lowballing it.
There is a ray of hope, however. Obama has made commitments at the G20 meetings for 3 billion dollars to help small countries with the fight against global warming. And he got commitments from Canada and other countries as well. This and the agreement with China about reducing emissions may turn out to be a critical moment that might bring us to the 2 degree Celsius limit. I have to say I've been pretty depressed about what will happen, but this does give me some degree of optimism.
The big obstacle are the Republicans in the U.S. Congress. May they not prevail.