Subscribe free to our newsletters via your
. Earth Science News .

Subscribe free to our newsletters via your

Bangladesh delta is key buffer against global warming, says study

by Staff Writers
Paris (AFP) Nov 14, 2007
The Bay of Bengal is an unexpected weapon against global warming as it helps store vast quantities of terrestrial carbon brought down by the Ganges-Brahmaputra river systems, a study says.

Rivers bring down to the sea carbon in the form of soil and vegetal debris, washed down from slopes, fields and banks. But little is known about what happens to this carbon-rich sediment once it reaches the river's mouth.

Some research -- conducted in the churning waters of the Amazon basin -- has suggested that 70 percent of this river-borne organic carbon returns to the atmosphere as gas, thus adding to the greenhouse effect from fossil fuels.

But research published on Thursday in the British science journal Nature says the picture is more complex.

A team led by Valier Galy of France's Nancy University estimates that around 70-85 percent of the terrestrial carbon that sweeps down the Ganges-Brahmaputra systems from the Himalayas settles to the sea floor rather than escapes to the atmosphere.

The reason: high rates of erosion in the Himalayas cause high rates of sedimentation in the so-called Bengal Fan in the Bay of Bengal. Between a billion and two billion tonnes of sediment are transported each year from the Himalayas to the Bengal coast.

As a result -- unlike at the mouths of the Amazon -- the thick, fast-growing sediments are not exposed to much oxygen, and this starves microbes of the fuel they need to biodegrade the organic matter.

Eventually, powerful currents transfer the sediments to deeper water, where they settle on the ocean bed, safely storing the carbon for potentially millions of years.

The finding sheds light on a previously unknown "sink," the term for a natural phenomenon that stores greenhouse gas rather than let it be released into the atmosphere. Sinks thus help cool Earth's surface.

By some estimates, around a third of the carbon that falls to the ocean floor is of terrestrial origin (the bulk of the remainder comes from dead plankton).

According to Galy's estimates, the Bengal basin is such an efficient burier of carbon that it could account for between 10 and 20 percent of the total terrestrial carbon stored on the ocean bed.

In two separate studies, released online by Nature on Wednesday, researchers in the Netherlands and New Zealand say they have identified two hardy species of methane-gobbling bacteria that could also play the role of a "sink."

The bugs, which live in the roasting-hot environment of mud volcanoes, were identified at a fumarole near Naples and at Tikitere, or Hell's Gate, in New Zealand.

The specialised "methanotrophic" germs, named Acidimethylosilex fumarolicum and Methylokorus infernorum respectively, could play a useful role in mopping up some of the methane burped from Earth's crust, say the authors.

Methane is the second biggest greenhouse gas by volume after CO2 but is many times more efficient than CO2 in trapping solar heat.

Email This Article
Comment On This Article

Related Links
Climate Science News - Modeling, Mitigation Adaptation

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

World body warns over ocean 'fertilisation' to fix climate change
London (AFP) Nov 12, 2007
Countries gathered under an international accord on maritime pollution have warned against offbeat experiments to tackle climate change by sowing the sea with chemicals to help soak up airborne carbon dioxide (CO2).

  • Emergency Response
  • Electronic Nose Could Detect Hazards
  • Court upholds jail term for Japanese architect
  • SkyPort Signs Contract With Cisco For Emergency Response Satellite Connectivity

  • Bangladesh delta is key buffer against global warming, says study
  • World body warns over ocean 'fertilisation' to fix climate change
  • TAU Professor Finds Global Warming Is Melting Soft Coral
  • Groups oppose "ocean fertilisation" in Philippines

  • Strange Space Weather Over Africa
  • KAGUYA Captures The Earth Rising Over The Moon
  • Earth Observation Essential For Geohazard Mitigation
  • SPOT - The World's First Satellite Messenger Now Shipping

  • Japan, China still stuck on energy sea spat
  • Baker Institute Study Shows Big Five Oil Companies Limit Exploration
  • Alternative fuels may boost pollution: report
  • Analysis: Poll finds energy tax support

  • Repellents Between Dusk And Bedtime Make Insecticide-Treated Bednets More Effective
  • Global Fund approves over 1 bln dlrs in new grants to fight disease
  • Bug-Zapper: A Dose Of Radiation May Help Knock Out Malaria
  • Failed AIDS vaccine may have increased infection risk

  • Together We Stand: Bacteria Organize To Survive Hostile Zones
  • Monkeys rampage in Indian capital
  • Changing Environment Organizes Genetic Structure
  • Time-Sharing Birds Key To Evolutionary Mystery

  • Record amount of waste dumped in China's Yangtze River
  • Britain the 'dustbin of Europe': official
  • Ignored and harassed, Indian scavengers demand better work life
  • UN demands deal to phase-out use of mercury

  • China now has 18 million more young men than women
  • Human Ancestors: More Gatherers Than Hunters
  • One-child Chinese families prefer it that way
  • Key To False Memories Uncovered

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement