Climate Scientists Urge Aggressive Action to Curb Global Warming

In what's being called "the most comprehensive report ever on climate change," the National Academy of Sciences urged aggressive action to curb global warming, including a cap-and-trade program and taxes on carbon emissions.

Three studies requested by Congress issued Wednesday provide the broad outlines for a national strategy to deal with climate change, The Los Angeles Times reported. Two more studies are still to come.

Bold actions are necessary because "climate change is occurring, the Earth is warming ... concentrations of carbon dioxide are increasing, and there are very clear fingerprints that link [those effects] to humans," said Pamela A. Matson of Stanford University, who chaired one of five panels organized by the academy.

The scientists recommended that the United States restrict its carbon emissions to a total of 170 billion to 200 billion tons of greenhouse gases from 2012 to 2050. That would add up to a nearly 80 percent reduction of carbon compared to current levels.

"That's a very challenging task," scientist Robert W. Fri told the Times. "At the current rate of 7 billion tons per year, we would use up the allotment well before 2050. Even if all available and emerging technologies could be deployed to their fullest technical potential, it is clear we will still need new and additional emission reduction options."

The report also pushed for an emissions trading program known as cap-and-trade, which would set a limit on the amount of greenhouse gases a company could release. Companies that go over their limits could buy credits from firms with lower emissions. The Obama administration supports cap-and-trade and Congress is expected to renew debate on the issue this summer.

Read the report here.