Navigation Links
Man-made global warming started with ancient hunters
Date:6/30/2010

WASHINGTON Even before the dawn of agriculture, people may have caused the planet to warm up, a new study suggests.

Mammoths used to roam modern-day Russia and North America, but are now extinctand there's evidence that around 15,000 years ago, early hunters had a hand in wiping them out. A new study, accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union (AGU), argues that this die-off had the side effect of heating up the planet.

"A lot of people still think that people are unable to affect the climate even now, even when there are more than 6 billion people," says the lead author of the study, Chris Doughty of the Carnegie Institution for Science in Stanford, California. The new results, however, "show that even when we had populations orders of magnitude smaller than we do now, we still had a big impact."

In the new study, Doughty, Adam Wolf, and Chris Fieldall at Carnegie Institution for Sciencepropose a scenario to explain how hunters could have triggered global warming.

First, mammoth populations began to dropboth because of natural climate change as the planet emerged from the last ice age, and because of human hunting. Normally, mammoths would have grazed down any birch that grew, so the area stayed a grassland. But if the mammoths vanished, the birch could spread. In the cold of the far north, these trees would be dwarfs, only about 2 meters (6 feet) tall. Nonetheless, they would dominate the grasses.

The trees would change the color of the landscape, making it much darker so it would absorb more of the Sun's heat, in turn heating up the air. This process would have added to natural climate change, making it harder for mammoths to cope, and helping the birch spread further.

To test how big of an effect this would have on climate, Field's team looked at ancient records of pollen, preserved in lake sediments from Alaska, Siberia, and t
'/>"/>

Contact: Maria-Jose Vinas
mjvinas@agu.org
202-777-7530
American Geophysical Union
Source:Eurekalert

Page: 1 2 3

Related biology news :

1. Going green on hold: Man-made activities can affect blue haze, worlds weather
2. Persistent man-made chemical pollutants found in deep-sea octopods and squids
3. Man-made changes bring about new epoch in Earths history
4. Discovery of how coral reefs adapt to global warming could aid reef restoration
5. High-yield agriculture slows pace of global warming, say Stanford researchers
6. Large majority of Americans still believe in global warming, Stanford poll finds
7. Ecological Society of America explores global warming at its 95th Annual Meeting
8. Stanford pollster to discuss latest survey on global warming
9. Bodys own proteins may lead the way in global fight against tuberculosis
10. Small mammals -- and rest of food chain -- at greater risk from global warming than thought
11. New global coffee research initiative announced
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:8/22/2014)... birds and the bees. But that old expression ... The fertilization process for flowering plants is particularly ... and female reproductive cells. New research from an ... and including Carnegie,s Wolf Frommer, David Ehrhardt, and ... process that guides flowering plant fertilization. It is ...
(Date:8/21/2014)... reduction in smog-producing toxins in past decade, GTA ... study shows that while the Greater Toronto Area ... that contribute to smog, the city continues to ... Smog, which can cause or aggravate health problems ... produced by a set of complex photochemical reactions ...
(Date:8/21/2014)... -- Nxt-ID, Inc. (OTCQB: NXTD), a biometric authentication company ... that its shares of common stock and the warrants ... proposed underwritten public offering of common stock and warrants ... Market, subject to closing of its proposed underwritten public ... trade under the symbol "NXTD" and "NXTDW," respectively. ...
Breaking Biology News(10 mins):Calcium and reproduction go together 2Despite a significant reduction in smog-producing toxins, the Greater Toronto Area still violates Canada's standards for ozone air pollution 2Nxt-ID Approved for NASDAQ Capital Market Listing 2Nxt-ID Approved for NASDAQ Capital Market Listing 3
... Technological University (NTU) may be onto an ocean of discovery ... the mantis shrimp. The research is likely to lead ... and military body armour many times stronger. These findings ... top scientific journal, and focused on the mantis shrimp,s ability ...
... one half and the deaths of young children have declined ... of the world,s poorest countries have achieved spectacular progress in ... countries have been dropping twice as fast in recent years ... Rwanda and the United Republic of Tanzania, the rate of ...
... June 12, 2012 - The Reed Elsevier Environmental Challenge shortlist ... access to safe water and sanitation. The winning project will ... World Water Week in Stockholm and featured in the ... winner will receive a prize of $50,000 with a second ...
Cached Biology News:NTU researchers study little mighty creature for scientific breakthrough 2NTU researchers study little mighty creature for scientific breakthrough 3Good news: Fewer maternal and child deaths 2Good news: Fewer maternal and child deaths 3Good news: Fewer maternal and child deaths 4Good news: Fewer maternal and child deaths 5Good news: Fewer maternal and child deaths 6Good news: Fewer maternal and child deaths 7Reed Elsevier Environmental Challenge shortlists 2012 projects 2
(Date:8/22/2014)... 22, 2014 Ophthalmic drug delivery ... and challenging endeavors as the anatomy, physiology and ... to the foreign substances. Ocular drug delivery technologies ... medication and minimal use of needles; also it ... and provides specific targeting within the ocular globe. ...
(Date:8/22/2014)... Nerium International, the go-to, buzzworthy ... spotlight again. Nerium will showcase its signature NeriumAD® ... Contouring Cream to Hollywood’s elite at the official ... 66th Primetime Emmy® Awards. , Developed from cutting-edge ... trials show that NeriumAD night cream dramatically reduces ...
(Date:8/21/2014)... at the Institute for Molecular Medicine Finland (FIMM), ... developed a novel "man and machine" decision support ... aid was described in PLOS One ... based on computer vision algorithms similar to those ... of only the diagnostically most relevant areas. Tablet ...
(Date:8/21/2014)... SPRING, N.Y. , Aug. 21, 2014 /PRNewswire/ ... the launch of their Nutraceutical "TELO-20 for Dogs" ... and only Telomere-lengthening supplement in the world for ... ends of every chromosome in the body. A ... world,s leading experts in Telomere Science and Aging, ...
Breaking Biology Technology:Ocular Drug Delivery Technologies Market: Global Industry Analysis, Size, Share, Growth, Trends and Forecast 2014 - 2020 2Ocular Drug Delivery Technologies Market: Global Industry Analysis, Size, Share, Growth, Trends and Forecast 2014 - 2020 3Ocular Drug Delivery Technologies Market: Global Industry Analysis, Size, Share, Growth, Trends and Forecast 2014 - 2020 4Nerium International Joins Television’s Biggest Stars at Backstage Creations Giving Suite at the 66th Primetime Emmy Awards 2Nerium International Joins Television’s Biggest Stars at Backstage Creations Giving Suite at the 66th Primetime Emmy Awards 3A novel 'man and machine' decision support system makes malaria diagnostics more effective 2Telomere Biosciences Announces: TELO-20 for Dogs, the World's First Telomere-Lengthening Supplement for Dogs, to Promote Healthy Aging and Longevity 2Telomere Biosciences Announces: TELO-20 for Dogs, the World's First Telomere-Lengthening Supplement for Dogs, to Promote Healthy Aging and Longevity 3
... June 16, 2011 For a successful bioscience company ... From research institutions and knowledgeable workforce to suppliers and ... bring innovative solutions to today,s modern scientific challenges. Yet, ... challenge. Costs associated with R&D are high. Complexity in ...
... 2011 Dendreon Corporation (Nasdaq: DNDN ) today announced ... in London on June 21, 2011 at 9:30 a.m. GMT (4:30 ... available for replay from Dendreon,s website, www.dendreon.com .  If you ... archived on the site following the presentation. To access the replay, ...
... designed to trigger your emotions and your mind through your ... trigger a few more? What if you could smell or ... favorite characters on TV? Is it possible? Would audiences enjoy ... consumers in a new way? These questions formed the ...
Cached Biology Technology:Ohio's Bioscience Industry Thrives With World-Class Industry Collaboration 2Ohio's Bioscience Industry Thrives With World-Class Industry Collaboration 3Ohio's Bioscience Industry Thrives With World-Class Industry Collaboration 4Coming to TV screens of the future: A sense of smell 2Coming to TV screens of the future: A sense of smell 3