The Carbon Cycle: Implications for Climate Change and Congress
Abstract
Huge quantities of carbon are actively exchanged between the atmosphere and other storage pools, including the oceans, vegetation, and soils on the land surface. The exchange, or flux, of carbon among the atmosphere, oceans, and land surface is called the global carbon cycle. Comparatively, human activities contribute a relatively small amount of carbon, primarily as carbon dioxide (CO2), to the global carbon cycle. Despite the addition of a relatively small amount of carbon to the atmosphere, compared to natural fluxes from the oceans and land surface, the human perturbation to the carbon cycle is increasingly recognized as a main factor driving climate change over the past 50 years. If humans add only a small amount of CO2 to the atmosphere each year, why is that contribution important to global climate change? The answer is that the oceans, vegetation, and soils do not take up carbon released from human activities quickly enough to prevent CO2 concentrations in the atmosphere from increasing. Humans tap the huge pool of fossil carbon for energy, and affect the global carbon cycle by transferring fossil carbon which took millions of years to accumulate underground into the atmosphere over a relatively short time span. As a result, the atmosphere contains approximately 35% more CO2 today than prior to the beginning of the industrial revolution (380 ppm vs 280 ppm). As the CO2 concentration grows it increases the degree to which the atmosphere traps incoming radiation from the sun (radiative forcing), warming the planet.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 13, 2008
- Accession Number
- ADA490756
Entities
People
- Peter Folger
Organizations
- Library of Congress