By Neva Knott
It’s Autumn. It’s a time of change for trees. The growing season is coming to a close, though in walking around one can see some species are just now coming to fruit or seed. Leaves are beginning to turn and fall. As I watch colors move from green to gold and orange, I’m reminded of what trees do, how they function as part of the system of nature. Humans breathe out, and trees breathe in. It is the most basic symbiotic relationship. Trees breathe carbon dioxide and store—or sequester—it, keeping it out of the atmosphere. Just today, I read a New York Times report on the severity of global warming. As I reflect on this changing season, I see a solution to climate change—reforestation, planting trees.
The relationship between trees and global warming is much like shade and open areas on a hot day. When the sun is blazing, people and animals become too hot, and seek shade under a tree to cool. Same thing for the planet. The sun is beating down, and trees help with cool-down. The grass under the tree’s canopy remains green; the sidewalks of tree-lined streets are cool, and the homes there stay comfortable even in mid-afternoon. Stream-side trees keep water cool enough for fish to live. City trees invert the heat island effect—that sensation of bricks and concrete giving of warmth at the end of a hot day. While trees are working to cool things, they are also taking up carbon dioxide emitted by all the driving and industry of humans going about the day.
As trees grow, they accumulate carbon; yet, as they are logged, burn, or die and decompose, they release carbon back into the atmosphere. This process is called the carbon cycle. Carbon sequestration occurs when the carbon taken in is stored in the wood, leaves, roots, and soil of the tree. It is this capacity for storage of carbon that has become the important focus of carbon reduction forestry programs. Carbon sequestration also helps forests themselves. Global warming creates drier summers that lower the soil moisture available to trees, makes forests more habitable to pests, and increase susceptibility to wildfires.
As it stands now, the earth’s overall ecosystem is taxed by the amount of carbon emitted from driving and industry, using wood for fire fuel, and clearing land for development and agriculture. Without the amount of human-created carbon emitted into the atmosphere, the cycle maintains balance in the amount of carbon released, used, and stored. Climate change is attributed in part to an imbalance in the carbon cycle. Oregon’s emissions measure about 68 million metric tons per year. This averages to about 17 metric tons per capita, in contrast with the world average of about four metric tons. Changes in forestry management can help create carbon sequestration necessary to counteract climate change caused by excessive carbon emissions. For example, mature trees in forested areas of the United States sequester about 56 per cent of all US carbon emissions.
In the fall of 2011, Oregon State University scientist David Turner and his team published a study of carbon sequestration in Oregon’s forests. The study covers the area affected by the 1993 Northwest Forest Plan, legislation that requires a decrease in timber harvest to protect habitat, mainly for the Spotted Owl. The NWFP applies to western Washington, Oregon, and California, and includes both public and private lands. Turner’s team remarked, “An unintended consequence of the NWFP has been a change in the regional forest carbon balance [which is] so important in the context of climate change.” The team found that private forests are now close to carbon-neutral, storing about as much carbon as they release into the atmosphere. The big bonus is that public forests in the study area have become a carbon sink, or storage area, keeping more carbon than they output. Given that 84 per cent of Oregon’s greenhouse gases are CO2, the ability to store carbon quickly and efficiently is an important function of the state’s forests.
Here in Oregon, we pride ourselves on clean rivers, big trees, and healthy salmon runs, all of which come from healthy forests. Even so, Oregon forests are suffering the effects of over-logging, wildfires, and are generally degraded, just like anywhere else. Several governmental agency programs exist, each with a payment structure for planting trees and restoration work. These alliances are creating a system of ecological and economic renewal in areas of the state hard-hit by the limits on logging through the NWFP. The science of carbon sequestration is now being put to economic use.
The Bureau of Land Management Stewardship Program issues 10-year contracts, paying for forest restoration work such as thinning and blowdown removal. Many of these contracts work to decrease fire fuels. The Oregon Forest Resource Trust works to establish forests where there are none through afforestation and reforestation. Oregon’s Tree Farm Plan is a cost-share program that helps private owners develop and fund long-range sustainability plans for their forests. The Conservation Reserves Program pays agricultural landowners to improve stream riparian areas by planting trees.
Oregon forestry leaders are continuously looking for ways to blend forest health, timber harvest, and the economic growth of the state.
These programs all operate under the scientific findings that chopping down forests contributes greatly to climate change, by emitting stored carbon, and by destroying the carbon sequestration process. All efforts to leave existing trees standing and to grow more trees—afforestation, reforestation, sustainable harvesting—significantly decrease carbon release into the atmosphere as a greenhouse gas. All of these actions can create economic benefits to the communities in and surrounding the forests, thus alleviating rural poverty and serving as a vehicle for social and economic development.
As Dr. Turner’s study suggests, the potential for carbon sequestration is a money-making one. Carbon trading, also known as carbon-offsets marketing, is a system in which carbon producers—polluters—pay forest growers for the service of carbon sequestration. The basic idea is that the sequestration provided creates balance with the pollution. This system is increasingly becoming a revenue stream.
In Oregon, The Climate Trust is the only offsets trading firm. It operates as a non-profit to managing partnerships and projects set up to create carbon offset trades. Forest projects must sequester 50, 000 tons or more over the lifetime of the project—this equates to about 150 acres of forested land.
To date, the Deschutes River Riparian project is the only Oregon project with The Climate Trust. Encouragingly, the Trust has $6 million available for funding projects in the state.
Publically owned forests, such as those studied by Dr. Turner and his team, currently cannot participate in the carbon market. Policy-makers are debating an offsets program for federal forestlands, and hopefully it will change soon. I asked Peter Weisberg of The Climate Trust about barriers to and the future of carbon offsets. He stated that prices are still low—about $10 per credit is being paid, and one credit represents one ton of carbon stored. Weisberg looks to increase in price as a way to get more projects going.
People and forests are symbiotic in nature. This symbiosis unites us—all of us—around the world, and creates universal hope for global cooling.
As I look out my window, I see foliage that I know will be gone in a month, leaving my view barren and cold. Autumn, and then it’s tree-planting season—November through spring.