Global Climate Change: Carbon Sequestration

One of the more promising ways of reducing the rate of rise of the air’s CO₂ content is to encourage land management policies that promote plant growth, which removes CO₂ from the atmosphere and sequesters its carbon, first in vegetative tissues and ultimately in soils. Some of these policies deal with managed forests and agro-ecosystems, while others apply to natural ecosystems, such as unmanaged forests and grasslands. In all instances, however, questions abound. Can carbon inputs to soils really be enhanced or carbon losses reduced? Can carbon storage in recalcitrant fractions of soil organic matter be increased, making it possible to successfully maintain new stores of sequestered carbon for long periods? And what if global warming runs wild? Will the ensuing rise in temperature stimulate plant and microbial respiration rates, returning even more CO₂ to the air than is removed by photosynthesis and leading to a negative net ecosystem exchange of carbon? These important questions rank high on the priority lists of many research organizations concerned about the planet’s future climate and the sustainability of the biosphere.