The world's climate is changing, humans are causing it, and the United States should put a price on carbon soon to stanch emissions of the greenhouse gases responsible. That's the conclusion of three congressionally requested reports from the National Academies' National Research Council (NRC).
"This is our most comprehensive report ever on climate change," said Ralph Cicerone, president of the National Academy of Sciences (NAS), at a briefing today to discuss the effort, more than 2 years in the making and involving 90 scientists. It "analyzes the reality of climate change and how should the nation respond. ... It emphasizes why the United States should act now."
One reason is the strength of the climate science, said environmental scientist Pamela Matson of Stanford University in Palo Alto, California, chair of the NRC panel on advancing the science of climate change. "Climate change is occurring, Earth is warming," she said. "These climate changes are largely caused by human activities. ... Climate change is already having consequences."
Matson's words may echo the 2007 report of the Intergovernmental Panel on Climate Change (IPCC) that has taken considerable flak lately. But the new reports, totaling 823 pages, draw from the past 5 years of research that was completed too late to be included by IPCC. They also drew on earlier NAS efforts and more than a score of reports from the U.S. Global Change Research Program.
The three NRC panels also feature a set of players rather different from those who compromised IPCC. Economist Gary Yohe of Wesleyan University in Middletown, Connecticut, an IPCC veteran, recalls how the inaugural meeting of the panel on adapting to the impacts of climate change was his first such gathering in a decade in which three-quarters of his fellow panel members were unfamiliar to him.
After the science panel concluded that the evidence is strong enough to warrant immediate action, the second panel—on limiting the magnitude of future climate change—recommended what to do. Although that panel, chaired by economist Robert Fri of Resources for the Future in Washington, D.C., was asked only to provide "policy-relevant [but not policy-prescriptive] input," it recommended, in Fri's words, that "the United States set a future greenhouse gas emissions target in the form of an emissions budget."
The panel suggests that a "reasonable representative range for a domestic emissions budget" would correspond "roughly to a reduction of emissions from 1990 levels by 80 to 50percent" by 2050. The 80% reduction would be similar to the 2050 goal favored by the Obama Administration and by some members of Congress.
The most cost-effective way to achieve such emission reductions is carbon pricing, the report says, whether a cap-and-trade system, a carbon tax, or something else or a combination of the two. Whatever the specific means for achieving the goal, "meeting that emissions budget is a challenging task," said Fri. "We can't get there by just deploying what we know how to do," he said. New technologies must be developed along with increasing energy efficiency, expanding low-carbon energy sources, expanding nuclear energy in a viable way, and retrofitting old technology.
Adapting to the impacts of climate change, the subject of the third NRC report, has gotten short shrift so far, said panel chair Thomas Wilbanks of Oak Ridge National Laboratory in Tennessee. As a result, he said, "we emphasize process rather than specific actions" to adapt to those changes that are now inevitable. There is little experience with adaptation around the world, he noted, and it is usually going to be specific to particular locations. Adaptation research has also been meager. Simple actions with side benefits would come first, he said, but contingency planning should begin for effects so severe, such as a meter or more of sea-level rise along the Gulf Coast, that people and their infrastructure will have to be moved.