Mitigation of Climate Change in Brief

On April 12, 2014, the Intergovernmental Panel on Climate Change ("IPCC") published the third of three Working Group reports entitled Climate Change 2014: Mitigation of Climate Change. This report constitutes, along with a Synthesis Report due October 2014, the IPCC's Fifth Assessment Report on climate change ("AR5"). The aim of AR5 is primarily to guide the United Nations to prepare a new treaty to limit emissions in 2015.

AR5 shows that global emissions of greenhouse gases have risen to unprecedented levels despite a growing number of policies to reduce climate change. Never-theless, many pathways to substantial emissions reductions are yet available.

AR5 includes data up to 2010 and incorporates scientific literature about risks related to climate change, adaptation, and mitigation strategies (i.e., a human intervention to reduce the sources or enhance sinks of greenhouse gases). In essence, the report says emissions need to be cut off within a wide range of human activity, including energy production and use, industry, transport, buildings, agriculture, forestry and other land use, and urbanization.

About half of cumulative anthropogenic carbon dioxide emissions between 1750 and 2010 have occurred in the last 40 years. The report reveals that globally, economic and population growth continue to be the most important drivers of increases in carbon dioxide emissions from fossil fuel combustion. So, without additional efforts to reduce greenhouse gases emissions, baseline scenarios would result in global mean surface temperature increases between 3.7 and 4.8°C in 2100, when compared to pre‐industrial levels. 

IPCC experts are clear: The more we delay mitigation efforts through 2030, the more difficult it will be. Indeed, with drastic technological measures and changes in behavior, it would still be possible to limit the increase in global mean temperature to 2°C above pre-industrial levels. Nonetheless, to get there, greenhouse gas emissions will have to be cut by 40 percent to 70 percent, compared with 2010 levels, by midcentury, and to near zero by the end of this century. 

In addition to cutting greenhouse gases, AR5 provides that climate change can also be reduced with some significant measures in energy supply and highlights some recommendations, such as decarbonizing (i.e., reducing the carbon intensity of) electric generation, carbon dioxide capture and storage technologies, and, of course, deployment at significant scale of renewable energies.