Methane sediments do not contribute to climate change?

Methane sediments do not contribute to climate change? It is methane itself from the swamp that warms the Earth.

It is the expansion of the marshes rather than the melting of frozen methane layers that causes methane to be sprayed on the atmosphere - this is the new announcement by the international team led by the Institute of Research. Save Scripps Ocean at UC San Diego.

This finding is thought to be a relief for scientists and climate-conscious people from the fear that rapid global warming may have been the cause of methane melting in the past and Here this will repeat in the context of the increasingly hot Earth. By measuring the amount of carbon isotopes in methane from the air bubbles retained in the ancient ice, researchers have determined that the methane ceiling nearly 12,000 years ago, chemically, has related to the expansion of the marshes. Wetlands, where large amounts of methane are produced in the process of microbial decomposition of organic bodies, have expanded throughout the Earth's warming history.

"This is good news for the problem of global warming, because it proves that methane classes don't react to warming by releasing large amounts of methane into the atmosphere," said Vasilii Petrenko, a University of Colorado doctorate. , Boulder state said.

And the results appeared in Science on April 24.

Scientists have long been concerned about the possibility of a climate change going on that will melt the permafrost at the North Pole, and the warming of ocean water a day will cause methane emissions, this gas will in turn accelerate the warming of the Earth. Most methane is currently in solid form, in the form of methane layers in deep sea sediments and in permafrost. Low temperatures and great pressure of the ocean keep these methane layers stable and prevent them from escaping into the atmosphere.

The horizontal alignment of the ice layers shows that ice formation takes thousands of years in the Pakitsoq ice region.Earth learners often surveyed Greenland ice seams to gather ancient climate data.(Photo: Scripps Ocean Research Institute, UC San Diego)

Scientists estimate that the melting of 10% of sediments will cause a greenhouse effect equivalent to 10 times the amount of atmospheric carbon dioxide present. Meanwhile, warming takes place over the past century as a result of an increase of 30% in carbon dioxide in the atmosphere.

The research team, led by Scripps learners at Earth and Jeff Severinghaus, collected large samples of tapes that were unprecedented in climate change studies. The researchers cut 15 tons of ice from an area called Pakitsoq on the west bank of the Greenland ice sheet to sample the ancient atmosphere. Methane exists with low density in the air, and only one billionth contains carbon-14 isotopes, which the researchers need for analysis. In fact, the amount of carbon-14 isotopes in methane is very high, and the team concludes that the existing methane gas cannot come from hard methane layers.

'This is an important study because it once again confirms that swamp and moisture will change rapidly when there are sudden climate changes,' Severinghaus said. 'This clarifies the fact that the greatest effects of climate change in the future may be harmful to water resources and drought, rather than the harmful effects of rising temperatures. "

Methane gas has risen right after the climate change between the Younger Dryas and Money Boreal zones. During this event, the temperature in Greenland increased by 10 ° C (18 ° F) within 20 years. The amount of methane increased by 50% in 150 years, from 500 ppb (ie 1 billion molecules in the air, there are 500 methane molecules) to 750 ppb.

Together with Petrenko and Severinghaus, researchers from the Australian Nuclear Science & Technology Organization (ANSTO), Oregon State University, New Zealand National Water and Climate Research Institute, Danish Technical University , and the Commonwealth Scientific and Industrial Research Organization based in Australia also made contributions to the report.

The research was supported by the National Science Foundation, the Packard Foundation, the American Chemical Society, the ANSTO Southern Hemisphere Climate Documentation Project, and the New Zealand Science and Technology Foundation.

References:
Vasilii V. Petrenko, Andrew M. Smith, Edward J. Brook, Dave Lowe, Katja Riedel, Gordon Brailsford, Quan Hua, Hinrich Schaefer, Niels Reeh, Ray F. Weiss, David Etheridge, and Jeffrey P. Severinghaus.14 Measure CH4 in Greenland ice: Study the last CH4 sources at the end of the Glacier.Journal of Science, 2009;324 (5926): 506 DOI: 10.1126 / science.1168909