In the past environmentalists, from Lord Stern to Sir Paul McCartney, have urged people to stop eating meat because the methane produced by cattle causes global warming.From Telegraph UK.
However a new study found that cattle grazed on the grasslands of China actually reduce another greenhouse gas, nitrous oxide.
…Klaus Butterbach-Bahl, of the Karlsruhe Institute of Technology in Germany, carried out the study in Inner Mongolia in China. He found that grassland produced more nitrous oxide during the spring thaw when sheep or cattle have not been grazing. This is because the greenhouse gas, also known as laughing gas, is released by microbes in the soil. When the grass is long snow settles keeping the microbes warm and providing water, however when the grass is cut short by animals the ground freezes and the microbes die.
Dr Butterbach-Bahl said the study overturned assumptions about grazing goats and cattle.
“It’s been generally assumed that if you increase livestock numbers you get a rise in emissions of nitrous oxide. This is not the case,” he said.
Wednesday, April 14, 2010
Running Out of Ideas: Methane Isn't the Problem Either.
Subscribe to:
Post Comments (Atom)
Posts
1 comment:
Meanwhile, water vapor is the biggest greenhouse gas by a factor of about 100.
"Water vapor constitutes Earth's most significant greenhouse gas, accounting for about 95% of Earth's greenhouse effect (5). Interestingly, many "facts and figures' regarding global warming completely ignore the powerful effects of water vapor in the greenhouse system, carelessly (perhaps, deliberately) overstating human impacts as much as 20-fold.
Water vapor is 99.999% of natural origin. Other atmospheric greenhouse gases, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and miscellaneous other gases (CFC's, etc.), are also mostly of natural origin (except for the latter, which is mostly anthropogenic).
Human activites contribute slightly to greenhouse gas concentrations through farming, manufacturing, power generation, and transportation. However, these emissions are so dwarfed in comparison to emissions from natural sources we can do nothing about, that even the most costly efforts to limit human emissions would have a very small-- perhaps undetectable-- effect on global climate."
Post a Comment