from AARPMagazine.org

It’s becoming a legacy issue for older Americans: what type of planet are we leaving our children? One of the nation’s top reporters on the environment reveals the latest science behind climate change

KANGERLUSSUAQ, GREENLAND

I’m staring up at the crumbling edge of the frozen white cap cloaking most of this vast Arctic island. The ice is thousands of years old, yet melting relentlessly in the bright May sunshine, sending a torrent of gray water to the sea. With me is Joe McConnell, a snow scientist who just spent three weeks drilling samples from the ice sheet, which extends over an area four times the size of California and is almost two miles high at its peak.

McConnell, 49, an expert on the world’s frozen places, is from—of all places—the Desert Research Institute in Reno, Nevada. That incongruity isn’t so jarring when he explains that many of the world’s driest communities, from the Andes to the American Southwest, are home to the billion-plus people who get much of their water from mountain snow and glaciers.

The ice-gouged, U-shaped valleys around us, now covered with lichens and shrubs, show that the earth’s climate has changed naturally for billions of years, ever since there’s been an atmosphere. Great warmings and coolings have sent ocean levels rising and falling as enormous amounts of water were locked in glaciers or released like the flows we see here in Greenland.

But the current warming trend is happening much faster than previous hot spells, says McConnell, and none of the forces that usually affect climate—such as variations in the sun’s strength—are in sync with this recent change. Should these patterns continue, he believes, the consequences are clear. “If Greenland melted, it’d raise sea levels by twenty feet,” he explains. “There goes most of the Mississippi embayment. There go the islands in the South Pacific. Bangladesh is obliterated. Manhattan would have to put up dikes.” A similar amount of ice is vulnerable in western Antarctica, another focus of McConnell’s work. While this would most likely be a slow-motion sea change taking many centuries, gases being pumped into the atmosphere by cars, planes, factories, and power plants could raise the odds of such a shift.

“There’s definitely a lot of melting going on,” McConnell says, flinching as a crack echoes from the warming white ice cliff above and a towering slab tilts.

Welcome to life on the frontlines of climate change.

For nearly 20 years I’ve been reporting on the extraordinary idea that humans, mainly by burning billions of tons of fossil fuels, are nudging the planet’s thermostat by adding to the atmosphere’s see-through blanket of carbon dioxide and other “greenhouse gases,” which traps some of the sun’s energy. This quest has taken me from the shrinking sea ice at the North Pole to the burning forests of the Amazon, from the fraught political battlegrounds of Washington to the tenuous sands of the Maldives, a string of islets in the Indian Ocean where a sea level rise of a couple of feet—a real prospect in a warming century—could render the country uninhabitable. In all my time covering this issue, I’ve never seen the debate as heated as it is now, with talk show hosts, politicians, moviemakers, and novelists alternately claiming human-caused warming is a planetary emergency or a hoax.

But beneath the volleys of sound bites are real people with real concerns. When I give talks on global warming, quite a few of my over-50 peers in the audience remark that this is, at its heart, an issue of legacy. It is our children’s climate, and our grandchildren’s, that is being shaped by the building greenhouse effect. One disturbing part of that legacy is this: while half the gas billowing from smokestacks and tailpipes is typically absorbed by the oceans or plants each year, the rest remains stashed in the air for a century or longer, building like unpaid credit card debt.

NEW YORK CITY

In the intellectual equivalent of a pro-wrestling “smackdown,” two teams of combatants enter a plush, packed auditorium on the Upper East Side for a debate titled “Global Warming Is Not a Crisis,” staged by a group called Intelligence Squared U.S.

The climate-change debunkers include Richard S. Lindzen, 67, a meteorologist at the Massachusetts Institute of Technology who claims that human-caused warming is inconsequential, and Michael Crichton, 64, the novelist and moviemaker. Crichton stirred the climate debate with a 2004 novel, State of Fear, in which the bad guys were radical environmentalists trying to scare the world about global warming in order to line their pockets. Opposed are three climate scientists: one from NASA, one from a leading university, and one from a private group called the Union of Concerned Scientists. Most of the night focuses on their differences, mainly concerning the value of quick, aggressive cuts in greenhouse gas emissions.

Richard C.J. Somerville, 66, a veteran University of California, San Diego, climatologist, attacks the “not a crisis” position. “[A crisis] does not mean catastrophe or alarmism,” he says. “It means a crucial or decisive moment, a turning point, a state of affairs in which a decisive change for better or worse is imminent. Our task tonight is to persuade you that global warming is indeed a crisis in exactly that sense. The science warns us that continuing to fuel the world using present technology will bring dangerous and possibly surprising climate changes by the end of this century, if not sooner.”

But Crichton insists that pressing real-time problems trump an iffy, long-term one. “Every day 30,000 people on this planet die of the diseases of poverty,” he tells the crowd. “A third of the planet doesn’t have electricity. We have a billion people with no clean water. We have half a billion people going to bed hungry every night. Do we care about this? It seems that we don’t. It seems that we would rather look a hundred years into the future than pay attention to what’s going on now.”

What’s largely lost in the sparring—Crichton’s team prevails in an audience vote—is that the debate has not been about whether humans are contributing to rising temperatures. Crichton and Lindzen, both of whom consider former vice president Al Gore and his allies alarmists, readily agree that human-generated greenhouse gases warm the earth. Indeed, the list of people accepting the need to cut these gases includes former foes of environmentalists. One convert is evangelist Pat Robertson, who said on his 700 Club TV program last year that “it is getting hotter and the ice caps are melting and there is a buildup of carbon dioxide in the air.… We really need to do something on fossil fuels.” Another conservative taking warming seriously is former speaker of the House Newt Gingrich. “The evidence is sufficient,” he said in April, “that we should move toward the most effective possible steps to reduce carbon loading of the atmosphere.”

What’s driving the change in attitudes is a steadily growing body of scientific evidence on human activities and warming. A report released earlier this year by the Intergovernmental Panel on Climate Change—made up of hundreds of the world’s leading climate experts—said with 90 percent certainty that most of the warming since 1950 has been driven by the buildup of carbon dioxide and other greenhouse gases. The report concluded with “high confidence” that human-caused climate change was already affecting regional conditions from the poles to the Tropics, and that hundreds of millions of people could be harmed by coastal flooding, dwindling water supplies, and shifting weather patterns within a few decades. The changes could also drive many species toward extinction, particularly those with rapidly shrinking habitats, such as polar bears. Warming in this century, by many estimates, could be between three and eight times the warming in the 20th century, when the planet’s average temperature rose just over one degree Fahrenheit in all. The United States was among 113 countries that endorsed the report.

The new report also predicts a mix of consequences, not all bad. More rainfall and longer growing seasons will likely benefit higher latitudes for decades, while less rainfall and harsher droughts are likely in some of the world’s poorest places—most notably, Africa. An open-water Arctic Ocean in summers, while posing a threat to polar bears, could create new intercontinental shipping lanes thousands of miles shorter than existing ones.

What the debate comes down to is not whether changes are coming but when they’ll occur—and how severe they’ll be. There is serious scientific disagreement about such vital questions as how fast and far temperatures, seas, and storm strength could rise. Warmer waters, for example, could lead to more Katrina-strength hurricanes. Yet new studies find that hurricanes might be torn apart by wind conditions associated with, yes, rising temperatures. This uncertainty is not humanity’s friend, experts say, especially as the global population crests in coming decades, putting ever more people at risk of flooding, famine, and other climate-driven threats.