New report calls for “deep decarbonization” to stay within 2°C limit

Flickr user: mr_wood

Many countries have publicly gone on record as supporting the goal of limiting future climate change to 2°C. Although that creates some risks for future generations, it avoids some of the potentially catastrophic changes that would come with a 4°C rise.

Given what we know about the sensitivity of the climate to added greenhouse gasses, it's possible to calculate how much more carbon dioxide we can admit while still having a reasonable chance of staying within the 2°C envelope. What's striking about these calculations is how many large changes we'll have to make in order to get there. According to Jeffrey Sachs of Columbia University's Earth Institute, the per-capita emissions would have to drop from five tons annually (where they are now) to 1.6 tons by 2050.

To accomplish this, Sachs says that all nations will have to undergo a process he calls "deep decarbonization," which is part of the title of a report he's helped organize and deliver to the UN today. Pathways to Deep Decarbonization, prepared by researchers in 15 different countries, looks into what's needed to achieve sufficient cuts in our carbon emissions. The report finds that current government pledges aren't sufficient, and the technology we need to succeed may exist, but most of it hasn't been proven to scale sufficiently.