Climate Change & Natural Resources
Frequently Asked Questions: Natural Resources
Q: How do forests store carbon?
A: Forests are natural reservoirs of carbon storage. Trees remove carbon dioxide from the air during the photosynthetic process. Sunlight and carbon dioxide gas are converted into carbon, some of which is stored as fiber in tree trunks and branches, foliage, and roots. During the process, some carbon dioxide is released back into the atmosphere. But more carbon is absorbed by trees than is transpired. Worldwide, forests store an astounding quantity of carbon derived from the atmosphere. At maturity, about 50 percent of a tree’s dry weight is carbon. The overall biomass of a forest and its soils acts as a “carbon sink,” effectively sequestering, or storing carbon.
Q: What is the importance of forests to atmospheric carbon dioxide?
A: The Intergovernmental Panel on Climate Change (IPCC) estimates that out of the total 2.48 trillion tons of carbon stored in the global terrestrial ecosystem, 1.15 trillion tons is stored in forests. Boreal or northern forests alone account for close to 25 percent of total carbon stored in vegetation and soils in the Earth’s biosphere.
Q: Isn’t stored, or sequestered, carbon in forests eventually returned to the atmosphere?
A: Forest carbon is eventually returned to the atmosphere. The forest’s fibers, or biomass, eventually decays, is burned, or otherwise returns carbon gas into the air. Forest carbon storage can be extended as fibers are harvested for consumer goods such as building products, furniture, and other uses. The Intergovernmental Panel on Climate Change (IPCC) generally divides terrestrial sequestration approaches into those that store carbon for a century or longer, such as forests, and those that cycle carbon over shorter periods, such as rangeland and other land uses.
Q: How have the world’s forests changed over recent centuries?
A: Forests are naturally dynamic and change over time. Natural climate changes over the millennia prompt forests to advance and recede and change the species makeup over a given area. In recent centuries, however, human influences over forests have become much more profound. Research suggests that only half of the world’s forests cover remains from the last post-glacial era. Harvesting and land-use changeover to agricultural purposes drives much of the loss. In North America, a great deal of acreage has returned to forest cover over the past century. But tropical and subtropical deforestation remains a major concern to climatologists. An estimated 9.6 billion acres of forested lands remain worldwide.
Q: How have Montana’s forests changed over recent centuries?
A: Forests are naturally dynamic and change over time. Studies indicate that forest species have gradually changed elevations and geographic distributions in response to natural changes in climate. According to industry sources, Montana forests are at about 96 percent of the coverage found by early explorers --- about 23 million acres. But the species and age profile has changed over that period. The watercourse riparian forests in much of the eastern portion of the state differ from those found 200 years ago, for example, due largely to flood and fire controls of the modern era. And, of course, wooded bottomlands have been inundated by the waters of Fort Peck Reservoir and other water impoundments. Many of the trees of western Montana forests are succession species following timber harvest and fire. Many of these forests are decades away from the mature climax species found by early-day loggers. Fire suppression efforts over the past century have also allowed certain species and fuel types to dominate in some districts.
Q: How do major fire events in Montana and elsewhere contribute to carbon dioxide build-up in the atmosphere?
A: Forest fire events in Montana and elsewhere do contribute carbon dioxide to the atmosphere. According to the state of Oregon, the 2002 Biscuit Fire there burned almost a half million acres and emitted about one-fourth of the state’s atmospheric carbon contribution that year. According to some estimates, worldwide burning of forested lands contributes about 1 billion metric tons of carbon into the atmosphere per year. This figure is comparatively small compared to the estimated 8 billion metric tons contributed per year through the burning of fossil fuels. Still, most climatologists and silviculturalists think forest fire carbon contributions are an important area of study. Recent studies compare post-fire regeneration and carbon storage capabilities of various tree species as they mature against the carbon dioxide loss of the original fire event.
Q: How do Montana’s forests fit into Climate Change forecasts?
A: Montana’s forests are currently measured as net carbon sinks, sequestering more than 23 million metric tons of CO2 from the atmosphere. The Montana Climate Change Action Plan has forecast that the state’s forests will continue to sequester similar quantities of CO2 through the year 2020. However, recommendations to enhance the state’s forest resources could raise levels of forest sequestration if successfully acted upon.
Q: How will natural or human-induced climate changes likely affect Montana’s forests?
A: The forecast for Montana’s forests remains unclear. As the climate warms, the growing season for many forests may lengthen. And some studies indicate that forests worldwide may benefit from increased atmospheric carbon dioxide levels. But fire seasons in Montana may also lengthen. Moisture patterns may also change, with some forests receiving more and others less. The timing of moisture events may also affect forests, with spring runoff occurring earlier and drought stresses and insect infestations remaining major factors.
Q: How can Montana landowners and citizens help improve forest health?
A: The Montana Climate Change Action Plan offers several recommendations to enhance the health of the state’s forestry resources. Key recommendations include:
- Reduce conversion of forested lands to developed uses.
- Expand the forest land base through planting on historically forested and non-forested lands and aggressively replanting following fire and/or harvest.
- Launch an aggressive urban tree planting program.
- Improve management practices on private and state-owned forested lands to increase carbon stocks.
- Enhance the use and durability of wood products in building materials.
Montanans should consider these recommendations as they make decisions in their personal and working lives.
- Select wood products over synthetic substitutes whenever possible.
- If you are a property owner, consider planting trees. Consult a local forestry professional for species recommendations appropriate for your site. If you have trees on your property, manage the stands for good health and optimal carbon storage.
- If you are planning to develop property, preserve trees at every opportunity.
- Take an interest in the health and carbon sequestration possibilities of public forests. About 60 percent of Montana’s forested lands are public and should be managed for the enjoyment and betterment of the public.
