This process of carbon absorption and deposition is known as carbon sequestration. It then becomes deposited in forest biomass (that is, trunks, branches, roots and leaves), in dead organic matter (litter and dead wood) and in soils. Carbon is absorbed from the atmosphere through photosynthesis. A forest is considered to be a carbon sink if it absorbs more carbon from the atmosphere than it releases.Forest carbon is released when trees burn or when they decay after dying (as a result of old age or of fire, insect attack or other disturbance). A forest is considered to be a carbon source if it releases more carbon than it absorbs.Forests as carbon sources and carbon sinksįorests can act as either carbon sources or carbon sinks. Land-use changes include afforestation (that is, the creation of new forests where none exist) and deforestation (that is, the conversion of forests to non-forest land uses such as agriculture). This means tracking changes that result from forest growth, decomposition, disturbances (fire and insects), harvesting and land-use changes. Under the United Nations Framework Convention on Climate Change, Canada must monitor and report greenhouse gas (GHG) emissions and changes in the carbon stock in its managed forests. Since the industrial use of fossil fuels began, the net carbon balance has resulted in increases in the atmospheric CO 2 concentration from 280 parts per million to over 390 parts per million.Īs a major forest nation, Canada is working to understand how today’s changing climate will affect the global carbon balance, the health of the country’s ecosystems and the flow of goods and services provided to Canadian society.Ĭanada also has international reporting obligations. Defining carbon balanceĮarth’s carbon balance is calculated as the carbon emissions from human activities minus the carbon uptake by oceans and land systems. How well forests will continue to remove the proportion of carbon now being emitted by human activities will affect the future rate of carbon increase in the atmosphere. Carbon uptake by forests reduces the rate at which carbon accumulates in the atmosphere and thus reduces the rate at which climate change occurs.
Over the past four decades, forests have moderated climate change by absorbing about one-quarter of the carbon emitted by human activities such as the burning of fossil fuels and the changing of land uses. At a global scale, forests help maintain Earth’s carbon balance. This cycle is fundamental to life on Earth.įorests are a vital part of the carbon cycle, both storing and releasing this essential element in a dynamic process of growth, decay, disturbance and renewal. The “carbon cycle” refers to the constant movement of carbon from the land and water through the atmosphere and living organisms.
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