With global warming now an accepted fact of 21st-century existence, we are finally starting to think seriously about how we as a nation might turn it around, or at least slow it down. Global warming is largely due to the buildup of carbon dioxide and other gases in the atmosphere, leading to the well-known greenhouse effect (the trapping of heat in the atmosphere that should be escaping). The carbon dioxide results from a variety of human activities, such as emissions from coal-fired power plants, automobiles and airplanes, deforestation and land conversion.
One way to counter this buildup is by sequestering carbon in trees and other plants that breathe it in and store most of it in their cells. The more forested land we have, and the bigger the trees, the more carbon we can pull out of the atmosphere.
Many industries are now planting trees to offset their carbon emissions, but while this seems to be a simple solution, closer scrutiny reveals a more complicated picture. In many states, forestland has actually been increasing in recent decades, as trees fill in abandoned farmland. Yet according to U.S. Forest Service data, 23 of the lower 48 states had a net loss of forestland between 1997 and 2002. And even now, all the forestland in the United States offsets only about 10 percent of the carbon produced by industrial emissions. This percentage could be greatly increased via low-cost policies encouraging reforestation of deforested land, protecting existing forestland from development, and managing those lands to increase carbon stores.
Although investments in energy efficiency and clean energy will provide the only long-term solutions to climate change, forest sequestration can buy us time to develop those alternatives. Under our current policies, however, the United States—which is home to only 4 percent of the world’s population but produces nearly a quarter of the world’s carbon emissions—faces a very uncertain future.
Between 1982 and 1997, net forest acreage grew by 3.6 million acres, according to the U.S. Department of Agriculture’s National Resource Inventory. But this small shift masks much larger landscape changes. During the same period, more than 8 million acres of forestland were converted to agricultural uses, and 12 million acres were developed or converted to “other rural land.” Meanwhile, however, 23 million acres of new forestland took root on abandoned agricultural land, though the tree cover on these properties isn’t nearly as full as it was on the acreage we lost.
And as forests and farmland continue to be lost to development nationwide, the carbon sequestered there is released into the atmosphere. This is a particular problem here in the Southeast, where big timber companies are selling off their forestlands to take advantage of rising real-estate prices. A recent report by Environment North Carolina, “Losing Our Natural Heritage: Development and Open Space Loss in North Carolina,” found that the state has lost 2.37 million acres of cropland and forestland to development over the past 20 years (about 325 acres every day).
At present, however, those losses are being offset by the large numbers of abandoned farms that are growing back in trees. As a result, we, too, have seen a net increase in forestland over the last few decades. But this net gain won’t last. Over the next 20 years, North Carolina can expect to lose another 2 million acres of farms and forests (about 100,000 acres per year). In 2005, the state lost 1,000 farms, and between 2002 and 2005 North Carolina lost roughly 6,000 farms and more than 300,000 acres of farmland (again, mostly to urban sprawl).
Here in Western North Carolina, where farms and forestland are rapidly being converted into second homes and gated communities, we are at least blessed with a fairly large base of public land that serves as a big carbon sink for the Southern Appalachians. Proper appreciation of the role these public forests play in carbon sequestration could lead to new management scenarios valuing their ability to protect our fragile global environment more than their short-term resource potential. Federal, state and local tax incentives and assistance for landowners can also help. But much will depend on the will of our political leaders and on a public that understands and cares about the issue.
The U.S. Farm Bill, now being developed in the House and Senate, could provide significant incentives for protecting forests while helping farmers reforest degraded lands. The N.C. General Assembly’s recent approval of $128 million in conservation funding is encouraging, as are local-ordinance efforts in Western North Carolina to protect ridgelines and green space.
As individuals, however, our biggest impact still lies in what we choose to drive, eat and live in. These are simple choices, really, and you don’t even need to know what “sequestration” means in order to make them.
[Brent Martin runs The Wilderness Society’s Western North Carolina office in Franklin.]
To learn more about forest carbon, see The Wilderness Society’s report, “U.S. Forest Carbon and Climate Change: Controversies and Win/Win Policy Approaches,” available on-line at www.wilderness.org/Library/Documents/ForestCarbon.cfm