MEDIA ADVISORY
For immediate release
November 29, 2006

ESA Statement on Massachusetts et al. vs. U.S. Environmental Protection Agency
The Certainty of Global Climate Change

In response to the U.S. Environmental Protection Agency’s (EPA) argument in the U.S. Supreme Court case, Massachusetts et al. vs. U.S. EPA et al. that it would not regulate carbon dioxide due in part to scientific uncertainty, Alan Covich, President of the Ecological Society of America, the nation’s premier scientific society of ecological scientists, expressed dismay over the agency’s disregard for the widespread scientific consensus on the facts and effects of climate change. Covich said, “ESA strongly supports the scientific arguments regarding the certainty of climate change made by Massachusetts et al. as legitimate and accurate.”

The case currently before the Supreme Court was brought by a group of states, cities, and nonprofits that argued that, under the Clean Air Act (CAA), carbon dioxide is a pollutant and contributor to climate change and as such, the EPA must regulate carbon dioxide emissions. EPA argues, however, that it does not have the authority to regulate carbon dioxide and even if it had, the agency would not regulate carbon dioxide due in part to scientific uncertainty. The court’s decision will determine whether the CAA mandates that EPA regulate carbon dioxide, which may be a watershed decision for US action regarding climate change.

The CAA states that absolute scientific certainty is not necessary for regulation of a pollutant. Instead, the pollutant must “reasonably be anticipated to endanger public health or welfare.” [Section 202(a)(1)] In arguing that carbon dioxide cannot reasonably be anticipated to endanger public health or welfare due to scientific uncertainty, EPA chose only the points highlighting the absence of certainty from the 2001 National Research Council Report on climate change, but disregarded a general scientific consensus that climate change is indeed occurring. While certain facets of climate are less certain than others, current scientific understanding verifies and supports the following statements:

• The physics of the greenhouse effect are well understood by scientists. Certain atmospheric gases (including carbon dioxide) absorb radiation, causing a warming effect, and that greater concentrations of these gases will lead to an increase in surface temperatures. ¹
• It is certain that human activities have increased the concentrations of carbon dioxide in the atmosphere above levels in the geologically recent historical record, which has led to the recent global climate change. Carbon dioxide levels remained constant from the period 1000-1750, then increased more than 25% in the last 150 years.^{1 , 2} This had caused average global surface temperatures to rise approximately 0.6ºF; global average sea level to rise 0.1-0.2 meters; and ice extent in the Arctic to decrease by about 40%.^{2 , 3}
• It is virtually certain that greenhouse gas emissions, continued at the current rate, will cause additional warming. At the current emissions rate, carbon dioxide levels will double by 2100, leading to a likely temperature increase of 2.7-10.4ºF. ^{2 , 3}
• Climate change will increase threats to human health, especially in developing countries and lower income populations. Further increases in surface and ocean temperatures will cause an increase in drought, flood, and hurricane intensities, disrupt agricultural production, and expand the range of disease vectors. ^{2 , 3}
• The ecological effects of climate change are already observable and have been well-documented. Ecosystem disruptions including fire, drought, invasion of species, habitat shifts and coral bleaching events result in reduced biodiversity, increased extinction risk, and loss of ecosystem services. ^{2 , 3}
• The exact timing and magnitude of climate change depend on climate inertia and future emission rates. The elevated greenhouse gases currently in the atmosphere will continue to change the climate for an unknown period, even if all emissions are capped immediately. However, capping carbon dioxide emissions will significantly increase the timing of climate stabilization.^{2 , 4}
• It is likely that significant, intense, and abrupt events caused by climate change (such as local heat waves, intense droughts, or floods) will occur. The absence of a complete understanding of certain global processes may prevent predictions of events, including thermohaline circulation reduction, significant losses to Antarctic ice sheet, and altered Asian monsoons. ^{2 , 3}

Although current scientific understanding, by definition, constantly changes, these statements represent the latest information and are supported by a wide group of climate scientists. Many other scientific bodies, including the American Geophysical Union (AGU), the Geological Society of America (GSA), and the joint National Academies of Science (NAS), have issued similar statements:
AGU: www.agu.org/sci_soc/policy/positions/climate_change.shtml;
GSA: www.geosociety.org/aboutus/position10.htm;
NAS: nationalacademies.org/onpi/06072005.pdf

Said Covich, “Communication and widespread awareness of climate change information remains essential not only to conservation of natural resources, but also to the general well-being of the nation. The recognition of these facts by the Court in Massachusetts et al. vs. U.S. EPA et al. will provide significant support to the certainty of climate change that the administration cannot ignore.”

The Ecological Society of America is the world's largest professional organization of ecologists, representing 10,000 scientists in the United States and around the globe. Since its founding in 1915, ESA has promoted the responsible application of ecological principles to the solution of environmental problems through ESA reports, journals, research, and expert testimony to Congress. ESA publishes four print journals and one online-only, open-access journal Ecosphere and convenes an annual scientific conference. Visit the ESA website at www.esa.org or find experts in ecological science at www.esa.org/pao/rrt.

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