If adopted, this significant lifestyle change would also cut down on another animal problem: waste. Cow, pig and chicken excrement fester in lagoons, emitting methane—a short-lived but potent GHG. On the other hand, capturing that methane also offers an opportunity to create electricity. Biodigesters (covered tanks that employ bacteria to break down animal waste) produce abundant methane, says Albert Morales, executive vice president of Environmental Power, a purveyor of such systems. "The gas goes to a generator,'' he explains, "that generates power for the [electricity] grid."
Economists and other experts argue that offsetting coal-fired electricity generation may be the most promising use of such agricultural and forestry biofuels. While roughly 20 percent of the carbon in corn, for example, is recycled if turned into the motor fuel ethanol, as much as 95 percent of the carbon in the whole corn plant can be recycled if burned in electric power plants, McCarl says.
The pulp and paper industry, which creates large amounts of waste, is already utilizing such carbon recycling and generation. In fact, such manufacturers have become net exporters of energy in Canada by burning residue wood. This kind of efficiency could reduce GHG emissions in the U.S. alone "in the neighborhood of 300 million metric tons on an annual basis," McCarl says, "principally from burning biofuels for electricity and [from] forest management."
Forest management is the linchpin of any effort to combat climate change in these sectors, contributing the largest share of greenhouse gases. And it will not be as simple as building a fence around the world's forests. "We need to understand the dual role of forests of storing carbon and providing carbon to serve society's needs," Natural Resources Canada's Kurz says. "Choosing wood-based products has a much lower fossil fuel footprint than using some other building materials," such as concrete.
In Scandinavia, for example, forests cover more land now than in the previous century—thus increasing their carbon storage—while still being regularly harvested. "The more we can prolong the storage of wood products in human structures, the longer the carbon is kept out of the atmosphere. When we do get rid of it, we should burn it to offset fossil fuels, part of a cascading system of multiple uses," Kurz says. "Good forest management is typically also good carbon management."