Intergovernmental Panel on Climate Change Releases Second Report in Series

On March 30, Working Group II (WGII) of the Intergovernmental Panel on Climate Change (IPCC) released its report on climate change’s risk to human society. The Summary for Policymakers of WGII encompassed three years of labor, the work of 309 climate scientists and close to 2,000 experts from across the globe, as well as 12,000 peer-reviewed scientific papers, all compiled into one, succinct report. The report aims to evaluate “how patterns of risks and potential benefits are shifting due to climate change . . . how impacts and risks related to climate change can be reduced and managed through adaptation and mitigation . . . [and] needs, options, opportunities, constraints, resilience, limits, and other aspects associated with adaptation.”

As the scientific intergovernmental body responsible for publishing information relevant to the implementation of the United Nations Framework Convention on Climate Change (UNFCCC), the IPCC's reports are considered the global benchmark in climate change understanding. Last September, Working Group I (WRI) of the IPCC met in Stockholm and released the group’s fifth Assessment Report (AR5). WRI, which deals with the physical science of climate change, detailed the changes to the climate that can be expected from the likely 2 degrees Celsius (3.6 degrees Fahrenheit) rise in temperature by the end of the century. These changes include increased ice sheet melting, sea level rise, droughts, heat waves, and changes to precipitation patterns. [See EESI's article on last IPCC release]

The WGII report centered on the fact that climate risks are happening now and future impacts are more immediate than once believed. According to Stanford University Professor Chris Field, co-chair of WGII, “the climate changes that have already occurred have been widespread and have really had consequences. It is not the case that climate change is a thing of the future.”

Whereas the WGII report of 2007 contained less certainty in the area of food and water availability due to climate change, this update states that global wheat and maize production are already seeing reductions due to heat stress. All warming scenarios show the global stock of fish declining in the next hundred years and many species are especially at risk due to their sensitivity to ocean acidification. Shrinking glaciers will reduce vital water supply this century, disproportionately impacting the rural poor.

The scientists also found that the increase in greenhouse gas emissions will impact human health and well-being. Under-nutrition and water-borne diseases are expected to increase due to a lack of access to food and clean water. Climate change could also indirectly increase the risk of violent conflicts and displacement of people by exacerbating already stressed environments. A report by the Pentagon, released earlier in March, further supported this claim by stating, “the pressures caused by climate change will influence resource competition while placing additional burdens on economies, societies, and governance institutions around the world . . . that will aggravate stressors abroad such as poverty, environmental degradation, political instability, and social tensions.”

The report also states that a temperature increase of 2 degrees Celsius would cause losses in global income of between 0.2 to 2 percent, with a higher likelihood of losses at the 2 percent end of the range. The report notes that economic losses from climate change are difficult to asses and could actually be much higher.

U.S. Secretary of State John Kerry summed up the report's gist when he said, “Read this report and you can’t deny the reality: unless we act dramatically and quickly, science tells us our climate and our way of life are literally in jeopardy . . . let’s make our political system wake up and let’s make the world respond.”