U.S. Fish and Wildlife Service
According to the U.S. Department of Energy, in the past 60 years, the amount of anthropogenic carbon dioxide (CO2) emitted to the atmosphere, primarily because of expanding use of fossil fuels for energy, has risen from pre-industrial levels of 280 parts per million to present levels of over 365 ppm. Predictions of global energy use in the next century suggest a continued increase in carbon emissions and rising concentrations of CO2 in the atmosphere unless major changes are made in the way we produce and use energy - in particular, how we manage carbon.
The Earth’s natural carbon cycle moves CO2 into and out of the atmosphere. The oceans and land vegetation release and absorb over 200 billion metric tons of carbon into and out of the atmosphere each year. When the cycle is balanced, atmospheric levels of CO2 remain relatively stable. However, human activities are adding about 7 billion metric tons of carbon into the atmosphere every year, which is about 3 to 4 percent of the amount exchanged naturally. The oceans and land vegetation are absorbing about half of these emissions; the other half remain airborne for 100 years or longer. Land use changes have increased the unbalancing effects by replacing carbon sinks (e.g., natural vegetation, un-tilled soil) with landscape features that store carbon less efficiently (e.g., tilled soil, harvested crops).
A warming trend has been recorded on Earth since the late 19th century, with the most rapid warming occurring over the past two decades. The global temperature record shows an average warming of about 1 degree F over the past century. The ten warmest years have occurred since 1983, with seven of them since 1990. Recent evidence shows the 20th century was the warmest in the last 1,000 years. The 1990s were the warmest decade and 1998 was the single warmest year in the past millennium. If emissions of greenhouse gases continue unabated, scientists say we may change global temperatures and our planet's climate at an unprecedented rate for our society and those to come. Many fear the accumulation of greenhouse gases in the atmosphere is likely to cause long-term changes to the Earth's temperature, rainfall, snowfall, and other aspects of our climate.
Recent concerns over global warming have led scientists to identify ways to reduce greenhouse emissions. One way is to mitigate the increased emission of greenhouse gasses into the atmosphere by sequestering carbon in our land. Carbon sequestration refers to the concept of long-term storage of carbon in the terrestrial biosphere (e.g., trees, wetlands, prairies, etc), underground, or in the oceans so that the buildup of carbon dioxide (the principal greenhouse gas) in the atmosphere will reduce or slow. Carbon "sinks" such as wetlands, rangeland, and forests can make a substantial contribution to reducing net greenhouse gas emissions. Current efforts by the U.S. Fish and Wildlife Service to restore and protect wetland, prairie, forest, and savanna ecosystems are making an impact in this regard.
For additional information on carbon sequestration, visit these sites:
Growing Carbon: A New Crop that Helps Agricultural Producers and the Climate Too
This new brochure from the Soil and Water Conservation Society discusses the opportunities producers have to help efforts to slow climate change, to build a cushion against its harmful effects, and perhaps to grow a new cropcarbon.
Pots of Gold
For years farmers in the Upper Midwest have been plowing up prairie potholes, the tiny seasonal wetlands that dot their fields. But now that scientists have discovered that potholes can reduce greenhouse-gas emissions, farmers and businessmen are eyeing the wetlands as the region's newest cash crop.
This site outlines the U.S. Department of Energy's (Office of Science) carbon sequestration efforts.
- Carbon Sequestration in Terrestrial Ecosystems, CSiTE
The U.S. Department of Energy’s Office of Science - Biological and Environmental Research established CSiTE, a research consortium, to perform fundamental research that will lead to acceptable methods to enhance carbon sequestration in terrestrial ecosystems as one component of a carbon management strategy.