WASHINGTON – The United States has to lead the global fight on climate change by breaking with business-as-usual and setting tough standards for the amount of greenhouse gases it emits into the atmosphere, US scientists said Wednesday.
In one of three multi-hundred-page reports on climate change by the National Research Council, scientists said the United States should set a budget that would limit greenhouse gas emissions to a total of between 170 and 200 gigatons of carbon dioxide equivalent between 2012 and 2050.
That limit would correspond to a reduction of US emissions from 1990 levels by 80 to 50 percent, depending whether the upper or lower “budgetary level” is chosen, and would require “a major departure from business-as-usual emission trends,” the report said.
US emissions have been rising at a rate of one percent per year for the past three decades, and in 2008 reached around seven gigatons of carbon dioxide equivalent.
Even if emissions stuck at the 2008 rate and if the higher budget target of 200 gigatons was chosen, the US would exceed its emissions budget by 2041.
The NRC report urged the US to lead the way on reducing emissions so that other nations will follow, the scientists said.
“Although limiting emissions must be a global effort to be effective, strong US actions to reduce emissions will help encourage other countries to do the same,” they said.
The cap-and-trade system — where a total level of allowable domestic emissions is set, companies are given emissions quotas, and the small polluters can sell their surplus to firms that exceed theirs — was one of the most effective ways of reducing emissions, the report said.
Cap-and-trade was declared dead by Republican Senator Lindsey Graham two months ago, but a climate bill prop
osed this month by Democratic Senator John Kerry and Independent Joe Lieberman proposed setting up just such a system, even though it did not call it by name.
The senators' plan would cut US carbon emissions by 17 percent by 2020 from 2005 levels, going up to 83 percent by 2050.
The scientists warned, though, that putting a price on carbon would only work if the United States also improves energy efficiency, speeds up the development of renewable energy sources, develops new-generation nuclear power, and retrofits, decommissions or replaces facilities that belch greenhouse gases into the air.
One of the other reports issued as part of what the NRC calls its most comprehensive climate change study to date reaffirms US scientists' strong belief that climate change is occurring and is caused largely by human activities.
Climate change skeptics last year seized on a leak of thousands of emails and other documents from researchers at the University of East Anglia in Britain, which appeared to show scientists saying global warming was not as serious as previously thought.
A few months later, another scandal rocked the world of climate science, when the UN's Intergovernmental Panel on Climate Change (IPCC) was accused of basing a report about ice disappearing from the world's mountain peaks on a student essay and an article in a mountaineering magazine.
The third report released Wednesday urges US policymakers to take steps to reduce the country's vulnerability to climate change impacts that cannot be avoided, while stressing that adapting to climate change was not an alternative to limiting it.
The trilogy of reports were released as the US and more than 190 other nations continue to hammer out the details of a successor treaty to the Kyoto Protocol, which set a target of industrialized nations cutting emissions blamed for global warming by an average of five percent by the end of 2012 from 1990 levels.
The United States was the only major nation to reject the treaty, arguing it was unfair because it made no demands of fast-growing economies such as China, now the world's top carbon emitter.
