To curb the rate of climate change and maintain ecosystem services, the increase in surface air temperature must remain below 1.5 degrees Celsius, according to a recently published paper led by Shufen (Susan) Pan, an assistant professor in Auburn University’s International Center for Climate and Global Change Research and School of Forestry and Wildlife Sciences.
Along with colleagues from the Chinese Academy of Sciences, the AU team (Susan Pan, Hanqin Tian, Shree Dangal, Jia Yang, Bo Tao, Chaoqun Lu, Wei Ren, etc) found that global Net Primary Productivity, which measures the ability of terrestrial systems to satisfy human demand for food, fiber, wood, and bio-fuels, would level off and begin to decline at any increase above 1.5 degrees. This is a significant finding that supports the Copenhagen Accord and has the possibility to inform global policy on climate adaptation in the future.
Previously, world experts agreed in 2009 on a goal to reduce emissions enough to keep surface air temperature changes under 2 degrees C, a benchmark supported by G-8 leaders. However, the Copenhagen Accord, which called for the US and 185 other nations to commit to various mitigation and adaptation strategies, suggested for the first time that this 2-degree goal would not be sufficient. When the Copenhagen Accord was accepted, it included provision for a review in 2015 of the need to potentially aim for this 1.5 degrees C threshold. The paper is available online at http://dx.plos.org/10.1371/journal.pone.0112810.