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

he Yukon Territory, built up over thousands of years. They looked at pollen from birch trees (the genus Betula), since this is "a pioneer species that can rapidly colonize open ground following disturbance," the study says. The researchers found that around 15,000 years agothe same time that mammoth populations dropped, and that hunters arrived in the areathe amount of birch pollen started to rise quickly.

To estimate how much additional area the birch might have covered, they started with the way modern-day elephants affect their environment by eating plants and uprooting trees. If mammoths had effects on vegetation similar to those of modern elephants , then the fall of mammoths would have allowed birch trees to spread over several centuries, expanding from very few trees to covering about one-quarter of Siberia and Beringiathe land bridge between Asia and Alaska. In those places where there was dense vegetation to start with and where mammoths had lived, the main reason for the spread of birch trees was the demise of mammoths, the model suggests.

Another study, published last year, shows that "the mammoths went extinct, and that was followed by a drastic change in the vegetation," rather than the other way around, Doughty says. "With the extinction of this keystone species, it would have some impact on the ecology and vegetationand vegetation has a large impact on climate."

Doughty and colleagues then used a climate simulation to estimate that this spread of birch trees would have warmed the whole planet more than 0.1 degrees Celsius (0.18 degrees Fahrenheit) over the course of several centuries. (In comparison, the planet has warmed about six times more during the past 150 years, largely because of people's greenhouse gas emissions.)

Only some portionabout one-quarterof the spread of the birch trees would have been due to the mammoth extinctions, the researchers estimate. Natural climate change would have been responsi
'/>"/>

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:7/10/2014)... major cities in New Mexico, nearly every public golf ... than precious potable water supplies. Across the U.S. Southwest ... courses receive treated effluent. Reusing the effluent increases the ... and homeowners alike fertilize their lawns during the growing ... New Mexico State University turfgrass expert has a new ...
(Date:7/10/2014)...  Unisys Corporation,s (NYSE: UIS ) subsidiary in ... announced that it has been selected by the Dutch Custodial ... Basic Provision Biometrics solution for penitentiaries across The ... with a solution based on its open standards-based LEIDA ... contract is up to seven years, with the new system ...
(Date:7/10/2014)... Sweden , July 7, 2014 ... its first major design win (DW). A Chinese Top 5 ... the planned start of mass production in October 2014.   ... a Chinese Top 5 smartphone OEM, which has a planned ... and a target sales volume for this phone of 3 ...
Breaking Biology News(10 mins):'Tailored' water -- the latest in lawn care 2Unisys Delivers New Basic Provision Biometrics Solution to Dutch Custodial Institutions Service 2Unisys Delivers New Basic Provision Biometrics Solution to Dutch Custodial Institutions Service 3FPC Wins DW for 1021 Touch Sensor for Flagship Smartphone from Chinese Top 5 Smartphone OEM 2
... (DOE) National Renewable Energy Laboratory (NREL) and collaborators released ... Radiation Database, a web-based technical report that provides critical ... in the U.S. and its territories. ... 2006-2010 for the first time. It also features improved ...
... new motivations to serve their kids vegetables. A new ... by simply serving vegetables with dinner, the main course would ... thoughtful and attentive. , "Most parents know that vegetables ... American dinners," said lead author Brian Wansink, PhD, the John ...
... A new review of existing studies points toward a potential ... or tooth decay. The review, published in the December ... trials, spanning the 1920s to the 1980s, on approximately 3,000 ... was associated with an approximately 50 percent reduction in the ...
Cached Biology News:NREL updates solar radiation database 2New review associates vitamin D with lower rates of tooth decay 2New review associates vitamin D with lower rates of tooth decay 3
(Date:7/11/2014)... DUBLIN , July 11, 2014 ... in part) in, into or from any jurisdiction where to ... of such jurisdiction.  Shire plc ("Shire" or the ... Bloomberg article this afternoon.  Shire confirms it has held a ... being made by Shire without the prior agreement or approval ...
(Date:7/11/2014)...  Researchers have pioneered a revolutionary new way ... called Virtual Finger, allows scientists to move through ... synapses using the flat surface of their computer ... studies orders of magnitude more efficient, saving time, ... many areas of experimental biology. The software and ...
(Date:7/10/2014)... July 10, 2014 Understanding the need ... cell lines, and the gap that currently exists in ... expand its industry-leading portfolio of validated ion channel and ... channel-expressing cell lines, as ion channels control many critical ... this activity creates the potential to treat a variety ...
(Date:7/10/2014)... July 10, 2014 EvoDerma ’s NOOME ... This rejuvenating device now comes with a second treatment cup ... time. , The new cup is thinner on the edges ... to target rough, thin and uneven surfaces on the face, ... for a stimulating treatment on areas such as the cheeks ...
Breaking Biology Technology:Shire plc - Statement re: Media Speculation 2Virtual Finger Enables Scientists To Navigate And Analyze 3D Images Of Complex Biological Structures 2Virtual Finger Enables Scientists To Navigate And Analyze 3D Images Of Complex Biological Structures 3Leader in Ion Channel Research Announces Newly Validated and Re-Engineered Cells 2Leader in Ion Channel Research Announces Newly Validated and Re-Engineered Cells 3Introducing a New Bonus Treatment Cup for EvoDerma’s NOOME Anti-Aging Motion 2
... curiosity and re-stimulates scientific interest through compelling stories at technology's ... in the midst of a subdued background with simple tutorials ... offered to encourage further inquiry and study. , ... ...
... years the only way to shape metal has been ... nanotechnology, metalworking involves carving metals with electron beams or ... developed a method to self-assemble metals into complex configurations ... bacterial cell by guiding metal particles into the desired ...
... Laboratories, Inc.,(NYSE: FRX ), an international manufacturer ... 2009 First Quarter financial results,before the U.S. stock ... that,day, at 10:00 AM EDT, Forest will host ... Chief Operating Officer and Frank Perier, Senior,Vice President ...
Cached Biology Technology:"Brave New Reality" Provides a Wide Spectrum of High Tech News and Easy Science. 2"Brave New Reality" Provides a Wide Spectrum of High Tech News and Easy Science. 3Metals shape up with a little help from friends 2Metals shape up with a little help from friends 3Forest Laboratories, Inc. Sets Date and Conference Call for Fiscal 2009 First Quarter Earnings 2
... protein assay reagents package is used for determining ... and detergents. The RC DC protein assay is ... for 500 standard assays: 250 ml RC reagent ... alkaline copper tartrate solution, 2 L dilute Folin ...
... SureLINK Bioconjugation Kit provides a powerful ... carbohydrates and nuceleic acids. The kit provides ... with reagents for quantifying conjugation efficiencies. It ... fluorophores, biotin and other tags with a ...
...
MAb to HLA, Class II-DR+DP Dry Ice: No Preservative: NaN3 Availability When Not in Inventory: 14-21 Business Days...
Biology Products: