The Big Fix
On June 23, 1988, NASA's chief climate scientist, James Hansen, traveled to Capitol Hill to testify before the Senate Committee on Energy and Natural Resources. As it happened, the temperature in Washington that day hit 98 degrees, overwhelming the air-conditioning system in the hearing room. Hansen told the sweltering lawmakers that the four warmest years on record had all occurred in the 1980s, that 1988 was on track to be the warmest year yet, and that, overall, global temperatures had risen by nearly half a degree over the previous three decades. He described the odds that this increase had occurred by chance as negligible-around the order of 1 percent. "The greenhouse effect has been detected," he said. "It is changing our climate now."
In the two decades since Hansen's Senate testimony, average global temperatures have risen by another half a degree. Just as he predicted, 1988 broke all previous temperature records. The 1988 record, however, has long since been overtaken: the 10 warmest years on record have now all occurred since 1995. (The very warmest was 2005, 2007 ranks fifth, and 2006 sixth.) Global warming is today widely recognized as one of the greatest dangers facing humanity -- United Nations Secretary General Ban Ki-moon has called it "the defining challenge of our age" -- as well as a threat to countless plant and animal species. And yet, over the past 20 years, no real progress has been made toward dealing with the problem. Indeed, just the opposite. Between 1988 and 2005, U.S. carbon dioxide emissions grew by almost 20 percent, from less than five billion tons to almost six billion tons a year, while global emissions during the same period climbed by 34 percent.
Over the past few years, I've interviewed scores of experts on climate change, including Hansen. A point that they have stressed to me over and over again is the extreme urgency of the situation. The time "is already five past midnight," said Konrad Steffen, a climatologist at the University of Colorado. (At the time of our conversation, I was visiting Steffen's research station on the Greenland ice sheet, which holds enough water, were it to melt, to raise global sea levels by 20 feet.)
What is crucial to understand, these scientists emphasize, is that the problems associated with rising temperatures become inevitable long before they are actually experienced. There is a time lag in the system; it takes several decades for the earth to respond fully to any change in greenhouse gas levels. Thus, global warming is always much farther along than it appears. Scientists have estimated that in addition to the one degree of warming that has already occurred, another degree of warming has, in effect, been built into the climate, and will take place even if greenhouse gas concentrations could -- somehow -- be held constant at today's levels.
"I've been involved in a number of fields where there's a lay opinion and a scientific opinion," Robert Socolow, codirector of Princeton's Carbon Mitigation Initiative, told me. "In most of the cases, it's the lay community that is more exercised, more anxious. But, in the climate case, the experts -- the people who work with the climate models every day, the people who do ice cores -- they are more concerned. They're going out of their way to say, ‘Wake up! This is not a good thing to be doing.'"
What will it take to change the situation? After 20 years of climbing temperatures, shrinking glaciers, accelerating sea-level rise, progressively more dire warnings, and increasingly inexcusable attempts at denial, what is finally going to compel the United States to act?
Clearly, presidential leadership will be key. Both senators John McCain and Barack Obama have repeatedly spoken about the need to combat global warming, and that is a hopeful sign. Both men support cap-and-trade programs to reduce CO2 emissions: Obama has called for cutting them to 80 percent below 1990 levels by 2050; McCain wants to reduce emissions by that date to 60 percent below 1990 levels.
"John McCain stood up to the president and sounded the alarm on global warming five years ago," a McCain ad declares. "Today, he has a realistic plan that will curb greenhouse gas emissions. A plan that will help grow our economy and protect our environment." Obama, speaking after touring a solar-powered facility in Nevada this summer, said, "What we are seeing here... is that a green, renewable energy economy isn't some pie-in-the-sky, far-off future. It is now. It is creating jobs, now. It is providing cheap alternatives to $140-a-barrel oil, now. And it can create millions of additional jobs and entire new industries if we act now."
A growing number of corporate and religious leaders are also speaking out in favor of carbon limits. By now, just about everyone has seen the ads, sponsored by Al Gore's Alliance for Climate Protection, that show the Reverend Al Sharpton and the televangelist Pat Robertson joking about how they disagree about everything except the need to save the planet. In May, Alcoa, General Electric, National Grid, and Pacific Gas & Electric joined with groups like the Natural Resources Defense Council and Environmental Defense to urge the Senate to approve the Lieberman-Warner Climate Security Act, which would have for the first time, imposed a cap on U.S. carbon emissions.
"A ‘yes' vote for the Climate Security Act represents historic leadership to advance bipartisan solutions to climate change," the coalition wrote in a May letter to members of the Senate. "A ‘no' vote will slow progress and maintain the status quo, which only increases the risk of unavoidable consequences."
Meanwhile, when oil hit $140 a barrel this summer, it seemed finally to bring home to Americans a message that decades of warnings from environmentalists had failed to: finite resources don't last forever. Lately the news has been filled with stories of Americans rethinking gas-guzzling cars, long commutes, and hard-to-heat McMansions. A recent report by Cambridge Energy Associates, a private company that advises corporations and governments on energy and environmental matters, notes that "for the first time since the 1970s and early 1980s the number of miles driven by Americans has clearly begun trending downward." In July, at the G8 meeting in Hokkaido, Japan, the United States for the first time agreed to a numerical target for emissions reductions, pledging, along with the world's other industrialized nations, to cut CO2 emissions in half by 2050.