Of course, transportation shows how difficult it will be to achieve the long-term goal of nearly eliminating greenhouse gas emissions from all sectors. "Decarbonizing will require a dramatic change in the energy supply infrastructure," notes David L. Greene, a transportation analyst at Oak Ridge National Laboratory in Tennessee. Options include hydrogen fuel cells, electric hybrids fueled with biomass or electric cars that plug into the grid. "There is not enough biofuel," Greene adds. "So you will need hydrogen or electricity to decarbonize surface transport, plus strong policies to ensure that the carbon emissions from producing these energy carriers are sequestered."
Such carbon capture and storage will be critical to any efforts to combat climate change, particularly if coal continues to play a large power generation role. Unfortunately, sequestration has yet to be demonstrated on a large scale. Significant government funding will be required to prove this technology, admits James Connaughton, chairman of the White House Council on Environmental Quality. "This report underscores the need for collective action, underscores the need for action across all sectors of the economy, and underscores the need for some breakout technologies in fossil fuel power generation as well as in the area of fuels," he says. "The goal is reducing emissions and growing economies."
The report also provides estimates of what such changes might cost. These estimates range from an actual improvement of overall economic health to a loss of as much as 3 percent of global gross domestic product by 2030, depending on what level of greenhouse gases in the atmosphere is targeted. But "costs may be substantially lower under the assumption that revenues from carbon taxes or auctioned permits under an emission trading system are used to promote low-carbon technologies," the report notes; associated health benefits, such as decreased particulate pollution from cars, could make stringent action economically beneficial.
"The IPCC report demonstrates that costs can be manageable if action begins soon and is clearly articulated," IEA's Bradley adds. "Because of the long-lived nature of the energy supply capital those investment decisions are needed now."
That will require leadership on both domestic and international levels from the U.S., the world's largest developed emitter, which has yet to commit to international reduction targets or even a preferred level of atmospheric concentrations of greenhouse gases. "The U.S. taking a step is the next major thing to happen," says Billy Pizer, a senior fellow at the Washington, D.C.-based think tank Resources for the Future. "I don't know if it's going to happen in this administration but I think it's possible. It is not impossible to imagine this president coming up with a proposal."
Voluntary measures, like those the U.S. government currently employs, will not be enough. "Voluntary measures will not work, though they have some very modest impact," says Charles Kolstad, an economist at the University of California, Santa Barbara. "Countries need to take actions that provide incentives to individuals and businesses to reduce carbon—a price needs to be put on carbon."
According to the report and its authors, whatever action governments undertake will need to be faster than the sluggish flow of Bangkok traffic. "Mitigation efforts over the next two to three decades will have a large impact on opportunities to achieve lower stabilization levels," the report says. In transportation, it offers mandatory fuel economy standards and better infrastructure planning as ways to both avoid the nightmare of catastrophic climate change and urban gridlock.
"The short term is efficiency," Argonne's Plotkin says. And in the longer term? "Urban form has a big effect on how people travel and also what kinds of public transportation you can have. This is a long term thing but you have to start somewhere soon."