Jumping the 2 Degree Cap

A 2004 study published in Science by Stephen Pacala and Robert Socolow made the assertion that simply stabilizing CO2 emissions over the next 50 years would keep the world from experience dangerous climate change effects. Currently, there is general agreement in the goal to keep global average temperatures from rising 2 degrees Celsius above preindustrial levels, and to keep CO2 concentrations below 500 parts per million (ppm) in the atmosphere. However, a new study published by Steven J Davis of the University of California and Carnegie Institution of Washington, finds that Pacala and Socolow’s predictions may have been too optimistic, and that inaction over the past 9 years since the report was published have created a more dire situation for avoiding climate change.

Over the last several months, media outlets have been calling attention to the fact that the prospect of maintaining global average temperature increases to below 2 degrees C (3.6 degrees Fahrenheit) are simply no longer possible. Industrial countries would have already needed to begin drastically cutting CO2 emissions, starting back in 2010, and since little action has actually taken place over the last 2 years, the possibility of keeping enough CO2 out of the atmosphere to avoid topping the 2 degree cap is extremely unlikely. In fact, Davis’ study finds that if CO2 emissions stabilize at current levels for 50 years, CO2 concentrations in the atmosphere will reach 509 ppm in 2060 and increase to 540 ppm by 2100. So it appears that simply maintaining carbon levels aren’t going to cut it – reduction is necessary.

Even if emissions were reduced and the 2 degree celsius cap could be maintained, would that safeguard us from dangerous climate change effects? According to Paul Gilding, former Greenpeace head and writer of “The Great Disruption,” planning for 2 degrees “is an inadequate goal and a plan for failure.” In his book, Gilding states that few science groups believe 2 degrees is a safe limit, but rather it is merely politically realistic and simply “the best we can do.” So even being successful at maintaining the 2 degree limit is apparently failing to solve the problem.

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