Why bother reducing my carbon footprint? That's probably what many people asked after reading about a new study that predicts that even if carbon emissions were drastically reduced, droughts and other severe climate changes tied to the emissions would persist for 1,000 years.
So why drive less? Why buy a hybrid? Why promote renewable energy?
Because doing nothing, or doing less, would mean even more dire consequences, the study's authors and other scientists argue.
"If we don't slow down or stop emissions, the climate changes will get much larger and quite intolerable," Kevin Trenberth, head of climate analysis at the National Center for Atmospheric Research, said in an interview with msnbc.com.
The more dire scenarios for global warming envision water wars, food shortages or famine due to drought and the loss of huge swaths of farmland, torrential rains and severe flooding in some regions and rising oceans.
What the study, published Tuesday, and some earlier ones have done is raise the bar for policy changes. Many scientists now say that while it's crucial for individuals to reduce their carbon footprints, bigger strategies that can only come from government are necessary.
"This is a global problem and while individuals can do some, it needs concerted national leadership and international agreements," said Trenberth, who was not involved in the study.
Former Vice President Al Gore reinforced that notion Wednesday, testifying before the Senate Foreign Relations Committee about how the United States might rejoin international climate talks after the former Bush administration rejected mandatory carbon curbs in favor of voluntary action and technological fixes.
Susan Solomon, the lead author of the study and a researcher at the National Oceanic and Atmospheric Administration's Earth System Research Laboratory in Boulder, Colo., said that while climate change is slow, it's unstoppable.
Scientist writes to Obama
James Hansen, director of NASA's Goddard Institute for Space Studies, is one of the nation's more militant scientists when it comes to cutting carbon emissions.
Hansen, long known for pushing policy recommendations when most scientists have been reluctant to do so, has become a lightning rod for warming skeptics. Last month he took his activism to a new level, writing a letter to then President-elect Barack Obama in which he said that even stronger plans to fight warming, including Obama's, were much too weak.
"Policies being discussed in national and international circles now, which focus on 'goals' for emission reduction and 'cap and trade,' have the same basic approach as the Kyoto Protocol," Hansen wrote, referring to the 1997 international climate treaty, which has h ad mixed results. " This approach is ineffectual and not commensurate with the climate threat. It could waste another decade, locking in disastrous consequences for our planet and humanity."
Hansen told msnbc.com that he sent the letter via U.S. mail as well as through a colleague, John Holdren, who Obama appointed as his chief science adviser. He said he doesn't expect the mailed version to get through but hopes that Holdren will follow through once he's confirmed.
Holdren could not be reached for comment.
Drastic measures
Hansen had three recommendations, all of which are controversial:
- Phase out coal plants that don't capture or store carbonHansen says this is essential to counter warming. "Coal emissions must be phased out rapidly," he wrote to Obama. of America's electricity comes from power plants that burn coal. While Obama has championed "clean coal," the technology to capture and store CO2 is not yet proven.
- Tax carbon instead of capping itObama endorses a "cap-and-trade" system in which companies whose emissions are above established limits pay companies whose emissions are below the cap. Hansen rejects the system, saying it's full of loopholes and benefits consultants and traders. "A carbon cap that makes one more stinking millionaire on the backs of the public is going to infuriate the public," he wrote Holdren. "Me too." Hansen argues a tax would be much easier to impose and collect.
- Make nuclear power research and development a prioritySince they're carbon-free and produce vast amounts of electricity, nuclear power plants should be on the table if their costs and waste can be reduced, Hansen said. "One of the greatest dangers the world faces is the possibility that a vocal minority of anti-nuclear activists could prevent phase-out of coal emissions," he wrote.
Planning for basics like water
Even a course as drastic as Hansen's wouldn't eliminate warming, which means people must prepare to live in a warmer world.
"It is correct that we have to live with some climate change, and so we must plan for it and adapt to the changes in a way that is not disruptive," said Trenberth. "We are not planning adequately for the changes that are already emerging."
He expects water resources to be "one of the big pressure points on societies." So water managers, for example, will have to find ways to save water in times of plenty for use in times of drought, Trenberth said.
Engineering our way out?
Some scientists have suggested drastic solutions — geoengineering projects that include launching balloons that would release sulfates to mimic the cooling effects of volcanic dust.
Trenberth, for one, is "not a fan of geoengineering at all." First, he said, there's "the ethical question of who makes the decision to alter climate deliberately on behalf of all mankind and all nations, some of which may benefit from global warming — think of Siberia and Russia for instance."
"Secondly, any such endeavor has major uncertainties on whether it will work," he said.