When it comes to climate change, Americans are a skeptical lot: According to Pew Research Institute surveys, just 40 percent of us believe that global warming is a major threat to the country (compared, for example, with 70 percent of the Japanese and around 55 percent in most of Europe). But suffice it to say that the doubters do not include the attendees at the American Geophysical Union conference last December. Two weeks before Christmas, about 3,000 of them jammed into San Francisco’s Moscone Center to hear James Hansen, the world’s most prominent climate scientist and the indisputable rock star of the movement, deliver a keynote speech on an issue he’s devoted himself to for the past three decades—the “global-warming time bomb.”
There was a bit of a setback. As the last audience members were getting seated, an event organizer came onstage to announce that Hansen had apparently mixed up his dates and had not yet arrived in the city. The organizer urged everyone to return tomorrow—same time, same place. Twenty-four hours later, those 3,000 people were back in their seats, and then rising out of them, to applaud as the 72-year-old grandfather and self-described “reticent Midwestern scientist” took the stage with a sheepish grin and the assurance that he had simply overscheduled and was “healthy as a horse.”
Hansen then launched into a story that originated in his own front yard in Bucks County, Pennsylvania. For years, Hansen and his grandchildren have tended the milkweed on their land, hoping to host the offspring of the monarch butterflies that used to hatch on the plants every summer. Over the past two years, the butterfly population has declined to the point where, last year, Hansen spotted a lone male butterfly with a broken wing on his property. He was devastated. “The milkweeds wilting in the hot summer sun were like the moldering wedding cake in Great Expectations,” he later wrote. “How silly, right? We were only being stood up by an insect.”
But for Hansen, that insect’s failure to show up is one more casualty, among many, of a phenomenon he has been talking about since 1982, when he first testified before Congress about his work. Yet it wasn’t until this past May, after a wild year of mudslides, typhoons, droughts, floods and wildfires, among other weather calamities, that the federal government unequivocally verified most of Hansen’s warnings. “Climate change, once considered an issue for a distant future, has moved firmly into the present,” stated a study issued by the National Climate Assessment. Along with the altered migration pattern of various species in response to changing seasons (cue Hansen’s beloved monarchs), the report—the largest on the topic ever undertaken—cited effects ranging from rising sea levels, melting glaciers and an increase in extreme weather of all varieties to an uptick in seasonal allergies and insect-borne diseases. And, like Hansen, the scientists concluded that these grim outcomes are the fault of human beings. Why? Because we refuse to stop burning carbon-producing fossil fuels.
Hansen grew up in Denison, Iowa, one of seven children of a waitress and a tenant farmer who eventually moved the family into town so he could become a bartender. With the aid of a scholarship and money saved from a paper route, Hansen attended the University of Iowa, where he studied math, physics and astronomy in the 1960s under the legendary space scientist James Van Allen.
Curiously enough, Earth wasn’t even Hansen’s original planet of choice: He specialized in Venus—Earth’s brighter, sexier sister planet—and wrote his doctoral thesis on its atmosphere. In 1981, he became the director of NASA’s Goddard Institute for Space Studies, where he spearheaded the Pioneer Venus Project, which deployed two spacecraft to explore the solar winds on Venus and to map its surface. But after he and his colleagues noticed alarming changes in the Earth’s atmosphere, Hansen resigned from the Venus experiment (“a planet changing before our eyes is more interesting and important,” he explained) in order to better understand what was happening to his own planet.
Hansen’s first groundbreaking climate-change paper, co-published in 1981, made several dramatic predictions—all of which have since materialized. Among his prophesies were that the Arctic’s fabled Northwest Passage would open (via melting), the 1980s would get hotter, the number of drought-prone regions would increase and glaciers would start to melt and sea levels would rise. Most controversial of all was his contention that all of these changes stemmed from humans and their carbon-burning fuels.
Hansen submitted his paper four times—three times to the journal Science, and once to Nature—before Science finally accepted it for the August 1981 issue. The paper’s significance, however, was immediately apparent: Just days after it was published, the New York Times reported his findings on page one. This exposure led to Hansen’s being called to testify before Congress. Before long, he was a regular fixture at congressional committee hearings.
But the testimony that put him—and his cause—permanently on the map occurred on June 23, 1988. As severe drought engulfed the country and Washington, D.C., sweltered in record 101 degree heat, Hansen was on Capitol Hill, politely but firmly explaining to the Senate Committee on Energy and Natural Resources that the whole world was going to get even hotter and more prone to extreme weather if no effort was made to stem the rampant use of fossil fuels. As Hansen left the committee room, he told a group of waiting reporters, “It’s time to stop waffling and say that the evidence is pretty strong that the greenhouse effect is here.” The line was quoted in newspapers and on news programs throughout the world and almost overnight Hansen became a folk hero.