Termites not to blame for methane.
Termites not to blame for methane
As concern builds over the threat of global warming global warming, the gradual increase of the temperature of the earth's lower atmosphere as a result of the increase in greenhouse gases since the Industrial Revolution. , scientists are trying to understand why atmospheric levels of methane, a greenhouse gas greenhouse gas
Any of the atmospheric gases that contribute to the greenhouse effect.
greenhouse gas , have more than doubled in the last two centuries. Researchers in the early 1980s suggested termites may deserve partial blame for the increase, but a comprehensive study downplays their role.
"Although the uncertainties are still very large, the weight of the scientific evidence is shifting toward the conclusion that termites are not an important global sources of methane," report M. Aslam K. Khalil and R.A. Rasmussen at the Oregon Graduate Center in Beaverton along wth Australian colleagues. They describe their work in the March 20 JOURNAL OF GEOPHYSICAL RESEARCH Journal of Geophysical Research is a publication of the American Geophysical Union. JGR was formerly titled Terrestrial Magnetism from its founding by the AGU's president Louis A. .
The researchers measured gases emitted by six termite termite or white ant, common name for a soft-bodied social insect of the order Isoptera. Termites are easily distinguished from ants by comparison of the base of the abdomen, which is broadly joined to the thorax in termites; in ants, there is species in Australia and reviewed the published data concerning how much food termites consume. They estimate termites worldwide emit about 12 X [10.sup.12] grams per year of methane, which amounts to about 2 percent of the methane released by all global sources each year. This number agrees with results from lab measurements and a field study in Africa.
In 1982, researchers from the National Center for Atmospheric Research The National Center for Atmospheric Research (NCAR) is a non-governmental U.S.-based institute whose stated mission is "exploring and understanding our atmosphere and its interactions with the Sun, the oceans, the biosphere, and human society. in Boulder, Colo., sparked the debate over termites when they reported estiamtes based on laboratory work that termites emit 150 X [10.sup.12] grams each year, which would constitute about 30 percent of the world's annual methane emissions. They also suggested that human activities such as deforestation deforestation
Process of clearing forests. Rates of deforestation are particularly high in the tropics, where the poor quality of the soil has led to the practice of routine clear-cutting to make new soil available for agricultural use. have boosted termite populations, which could explain part of the rise in methane concentrations.
Khalil says the earlier study overestimated the amount of food consumed by termites each year and did not take into account methane absorption by the ground near their mounds, a fact discovered only during field experiments. According to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
3. Khalil, the methane buildup in the atmosphere stems not from a population explosion in termites but from increasing numbers of rice fields, cattle and sheep.