I recently heard the term “carbon sequestration” in relation to climate change

I recently heard the term “carbon sequestration” in relation to climate change. What is it and how can it help stave off global warming?

—Bob Whelan, Pawtucket, RI

Carbon sequestration is simply the intake and storage of the element carbon. The most common example in nature is during the photosynthesis process of trees and plants, which store carbon as they absorb carbon dioxide (CO2) during growth. Because they soak up the carbon that would otherwise rise up and trap heat in the atmosphere, trees and plants are important players in efforts to stave off global warming.

Environmentalists cite this natural form of carbon sequestration as a key reason to preserve the world’s forests and other undeveloped lands where vegetation is abundant. And forests don’t just absorb and store large quantities of carbon; they also produce large quantities of oxygen as a by-product, leading people to refer to them as the “lungs of the earth.”

According to the Western Canada Wilderness Committee, the billions of trees in the boreal forest of the northern hemisphere that stretches from Russian Siberia across Canada and into Scandinavia absorb vast amounts of carbon as they grow. Likewise, the world’s tropical forests play an important role in naturally sequestering carbon. As such, environmentalists see preserving and adding to the world’s forest canopy as the best natural means for minimizing the impact of global warming caused by the 5.5 billion tons of carbon dioxide generated by factories and automobiles each year.

On the technological front, engineers are hard at work developing man-made ways to capture the carbon spewing from coal-fired power plants and industrial smokestacks and sequester it by burying it deep within the Earth or the oceans. The Bush administration has embraced carbon sequestration as a means to mitigate U.S. carbon dioxide emissions and is spending upwards of $49 million annually on research and development, hoping that the technology might play an important part in keeping greenhouse gas emissions out of the atmosphere. The U.S. is also funding related research in China in hopes of stemming the tide of Chinese CO2 emissions that are increasing quickly as that nation develops rapidly (China has already surpassed the U.S. as the largest coal consumer).

The Bush administration refused to sign onto the Kyoto Protocol, an international agreement adopted in Japan in 1997 calling on countries to limit their emissions of greenhouse gases. Instead, many environmentalists feel, they are pursuing carbon sequestration technology as a quick fix or “Band-Aid” approach that enables them to preserve the existing fossil fuel infrastructure instead of replacing it with clean renewable energy sources or efficiency gains. Essentially the technology involves disposing of carbon dioxide after it is produced, rather than trying to hold down its production in the first place. United Nations” studies suggest, however, that it might play a bigger role in fighting global warming this century than any other measure.