Global warming, in a way, made environmental activist Bill McKibben ill with dengue fever, he said in delivering in the 2011 Jill and Ken Iscol Distinguished Environmental Lecture April 21 in Kennedy Hall's Call Auditorium.

A few years ago in Bangladesh, McKibben was hospitalized in a dengue fever ward packed with shivering people. "I thought, this is not fair," he recalled. That's because dengue fever thrives in the "warm, wet world" created by global warming, he explained. As a result, in the past decade the mosquito-spread viral disease has "spread like wildfire" through Asia and South America" because of the burgeoning mosquito populations.

McKibben, the Schumann Distinguished Scholar at Middlebury College, is founder of 350.org, an international environmental group that organized the 2010 Global Work Party rally, convening more than 7,000 events in 181 countries.

The question of fairness, he said, arises because global warming is the result of greenhouse gases, particularly carbon dioxide (CO2) that is trapped in the Earth's atmosphere largely due to the burning of fossil fuels. Americans, he noted, "produce about 25 percent of the world's CO2," despite having only 4 percent of the world's population. But Bangladesh's carbon dioxide (CO2) output is negligible.

"I don't know how to do the moral math, except that one bed in four in that dengue clinic seems to me like it's on us," McKibben said.

He cited a 2008 NASA study asserting that any atmospheric CO2 concentration greater than 350 parts per million (ppm) "is not compatible with the planet on which civilization developed and to which life on Earth is adapted."

"We were both thrilled and horrified," McKibben said. Horrified, because the concentration was already at 390 ppm, making it clear that global warming is "a deep and present emergency to be tackled with everything that we have." But, he added, "suddenly, we had a tool with which to work": The number 350, which "means the same thing everywhere in the world."

The thermal radiation trapped by CO2 and other greenhouse gases in the atmosphere is "enough to knock every physical system on Earth pretty much out of kilter," McKibben warned. So far, he said, "we've raised the temperature of the Earth about 1 degree centigrade," and another 1-degree increase is coming.

To get environmental policy changed, he said "is not fundamentally a problem of education" but of countering the fossil fuel industry's power, political clout and money. Since we can't match their money, McKibben said, "we're going to have to find a different currency to work in. And that currency is bodies, spirit, creativity."

McKibben urged the audience to encourage local businesses to break ties with the U.S. Chamber of Commerce, which he called "the biggest player politically in the country," and sign petitions opposing its views. Last year, McKibben said, the Chamber of Commerce spent more on campaigns than the Democratic and Republican National Committees combined, and "94 percent of their campaign contributions went to climate-deniers."

He said: "Time is short, and the stakes are high. "I look forward to fighting side by side with you in the years ahead."

The annual Iscol lecture, presented by the David R. Atkinson Center for a Sustainable Future, brings prominent scholars, newsmakers, scientists and leaders to campus to discuss crucial environmental issues.

Joseph Mansky '12 is a writer intern for the Cornell Chronicle.