Exponential population growth combined with finite resources is the fundamental source of the planet's energy and climate problems, said Richard Allmendinger, Cornell professor of earth and atmospheric sciences, in a talk, "Energy and Global Warming: Flip Sides of the Same Crisis," at Baker Laboratory March 28.

Solutions must simultaneously address climate and energy crises and include energy conservation and efficiency, carbon dioxide capture and sequestration, and new carbon-free energy technologies, he said. "We must ultimately also bring population growth under control," he added.

He warned that the planet will have 9.4 billion people by 2050, up from more than 6.5 billion today -- although if current fertility rates continue at a constant rate, that 2050 figure could be as high as 12 billion. In the same time span, energy demands will double, and production of oil and natural gas will probably peak. Nontraditional fossil fuels that will replace oil and gas -- coal reserves, tar sands, oil shale and gas hydrates -- have a far higher environmental cost, raising the stakes even higher.

Allmendinger emphasized that an earth sciences perspective shows how the planet functions in the absence of humans, providing a better appreciation of the human impact.

On a per capita basis, the United States consumes twice as much energy as Eurasia and about four times more than China and India. "By conservative estimates, the world will need to double its energy supply by 2050 to sustain current growth," he said.

To make matters worse, new oil discoveries have been declining steadily since the 1960s, he said, because "80 percent of the world's oil and gas reserves are now state controlled, leaving private companies with a small resource base.

"In addition, many prospective exploration sites are now off limits for legitimate environmental reasons, and deflated prices in the 1980s and 1990s have reduced the economic incentive to explore. "Under those conditions, major oil companies found it easier to increase their reserves by buying other companies and their reserves," he noted.

Turning to such nontraditional hydrocarbons as gas hydrates, which may be immensely abundant, incur problems of access. "Gas hydrates are mostly located in difficult terrain underneath the ocean floor or in permafrost," said Allmendinger. "Exploitation of these resources carries considerable environmental risk, both from unintended release of greenhouse gases and from the possibility of triggering massive undersea slides, which have been associated with tsunamis in the North Atlantic about 5,000 years ago."

Coal will, in all probability, take over when oil and gas peak, he said, because the countries with the biggest energy needs in the next 50 years (China, India and the United States) also have the largest supplies of coal. China already is building a new coal-fired power plant every seven to 10 days. However, burning coal produces carbon dioxide, further exacerbating global warming, warned Allmendinger.

Allmendinger stressed four strategies:

Graduate student Kanika Arora is a writer intern at the Cornell Chronicle.