http://www.physorg.com/news195309866.htmlA cooler Pacific may have severely affected medieval Europe, North America
June 9, 2010
In the time before Columbus sailed the ocean blue, a cooler central Pacific Ocean has been connected with drought conditions in Europe and North America that may be responsible for famines and the disappearance of cliff dwelling people in the American West.
moreNASA: Easily the hottest spring — and Jan-May — in temperature record
Plus another record 12-month global temperature
June 10, 2010
NASA 5-10
Lmonth tied May 1998 as the hottest on record in the NASA dataset. More significantly, following fast on the heels of easily the hottest April — and hottest Jan-April — on record, it’s also the hottest Jan-May on record [click on figure to enlarge].
Also, the combined land-surface air and sea-surface water temperature anomaly for March-April-May was 0.73°C above the 1951-1980 mean, blowing out the old record of 0.65°C set in 2002.
The record temperatures we’re seeing now are especially impressive because we’ve been in “the deepest solar minimum in nearly a century.” It’s just hard to stop the march of manmade global warming, well, other than by reducing greenhouse gas emissions, that is.
Most significantly, the 12-month global temperature grew to 0.66°C — easily the highest on record.
http://www.sciencedaily.com/releases/20 ... 131318.htmArctic Climate May Be More Sensitive to Warming Than Thought, Says New Study
ScienceDaily (June 30, 2010) — A new study shows the Arctic climate system may be more sensitive to greenhouse warming than previously thought, and that current levels of Earth's atmospheric carbon dioxide may be high enough to bring about significant, irreversible shifts in Arctic ecosystems.
http://www.sciencedaily.com/releases/20 ... 131322.htmScienceDaily:
Hunting Weapon 10,000 Years Old Found in Melting Ice Patch
ScienceDaily (June 30, 2010) — To the untrained eye, University of Colorado at Boulder Research Associate Craig Lee's recent discovery of a 10,000-year-old wooden hunting weapon might look like a small branch that blew off a tree in a windstorm.
Nothing could be further from the truth, according to Lee, a research associate with CU-Boulder's Institute of Arctic and Alpine Research who found the atlatl dart, a spear-like hunting weapon, melting out of an ice patch high in the Rocky Mountains close to Yellowstone National Park.
Lee, a specialist in the emerging field of ice patch archaeology, said the dart had been frozen in the ice patch for 10 millennia and that climate change has increased global temperatures and accelerated melting of permanent ice fields, exposing organic materials that have long been entombed in the ice.
"We didn't realize until the early 2000s that there was a potential to find archaeological materials in association with melting permanent snow and ice in many areas of the globe," Lee said. "We're not talking about massive glaciers, we're talking about the smaller, more kinetically stable snowbanks that you might see if you go to Rocky Mountain National Park."
As glaciers and ice fields continue to melt at an unprecedented rate, increasingly older and significant artifacts -- as well as plant material, animal carcasses and ancient feces -- are being released from the ice that has gripped them for thousands of years, he said.
Over the past decade, Lee has worked with other researchers to develop a geographic information system, or GIS, model to identify glaciers and ice fields in Alaska and elsewhere that are likely to hold artifacts. They pulled together biological and physical data to find ice fields that may have been used by prehistoric hunters to kill animals seeking refuge from heat and insect swarms in the summer months.
"In these instances, what we're finding as archaeologists is stuff that was lost," Lee said. "Maybe you missed a shot and your weapon disappeared into the snowbank. It's like finding your keys when you drop them in snow. You're not going to find them until spring. Well, the spring hasn't come until these things started melting for the first time, in some instances, in many, many thousands of years."
The dart Lee found was from a birch sapling and still has personal markings on it from the ancient hunter, according to Lee. When it was shot, the 3-foot-long dart had a projectile point on one end, and a cup or dimple on the other end that would have attached to a hook on the atlatl. The hunter used the atlatl, a throwing tool about two feet long, for leverage to achieve greater velocity.
Later this summer Lee and CU-Boulder student researchers will travel to Glacier National Park to work with the Salish, Kootenai and Blackfeet tribes and researchers from the University of Wyoming to recover and protect artifacts that may have recently melted out of similar locations.
"We will be conducting an unprecedented collaboration with our Native American partners to develop and implement protocols for culturally appropriate scientific methods to recover and protect artifacts we may discover," he said.
Quick retrieval of any organic artifacts like clothing, wooden tools or weapons is necessary to save them, because once thawed and exposed to the elements they decompose quickly, he said.
An estimated 10 percent of Earth's land surface is covered with perennial snow, glaciers and ice fields, providing plenty of opportunities for exploration, Lee said. However, once organic artifacts melt out of the ice, they could be lost forever.
"Ninety-five percent of the archaeological record that we usually base our interpretations on is comprised of chip stone artifacts, ground stone artifacts, maybe old hearths, which is a fire pit, or rock rings that would have been used to stabilize a house," Lee said. "So we really have to base our understanding about ancient times on these inorganic materials. But ice patches are giving us this window into organic technology that we just don't get in other environments."
http://www.realclimate.org/index.php/ar ... #more-4719The Key to the Secrets of the Troposphere
Filed under:
* Climate Science
— rasmus @ 13 August 2010
Last year's climate summit in Copenhagen was a political disaster. Leaked US diplomatic cables now show why the summit failed so spectacularly. The dispatches reveal that the US and China, the world's top two polluters, joined forces to stymie every attempt by European nations to reach agreement.
more
What Carbon Cycle? College Students Lack Scientific Literacy, Study Finds
ScienceDaily (Jan. 7, 2011) — Most college students in the United States do not grasp the scientific basis of the carbon cycle -[HILITE]- an essential skill in understanding the causes and consequences of climate change, [/HILITE]according to research published in the January issue of BioScience.
Atlantic currents have seen 'drastic' changes: studyAtlantic currents have seen 'drastic' changes: study
January 4, 2011 The cold northern Labrador Current may be having a declining influence on the Atlantic Ocean
A woman celebrates after participating in the annual Coney Island Polar Bear Club New Year's Day swim in New York.
Scientists have found evidence of a "drastic" shift since the 1970s in north Atlantic Ocean currents that usually influence weather in the northern hemisphere, Swiss researchers say.
Scientists have found evidence of a "drastic" shift since the 1970s in north Atlantic Ocean currents that usually influence weather in the northern hemisphere, Swiss researchers said on Tuesday.
The team of biochemists and oceanographers from Switzerland, Canada and the United States detected changes in deep sea Atlantic corals that indicated the declining influence of the cold northern Labrador Current.
They said in the US National Academy of Science journal PNAS that the change "since the early 1970s is largely unique in the context of the last approximately 1,800 years," and raised the prospect of a direct link with global warming.
The Labrador Current interacts with the warmer Gulfstream from the south.
They in turn have a complex interaction with a climate pattern, the North Atlantic Oscillation, which has a dominant impact on weather in Europe and North America.
Scientists have pointed to a disruption or shifts in the oscillation as an explanation for moist or harsh winters in Europe, or severe summer droughts such as in Russia, in recent years.
One of the five scientists, Carsten Schubert, of the Swiss Federal Institute of Acquatic Sciences and Technology (EAWAG), underlined that for nearly 2,000 years the sub polar Labrador current off northern Canada and Newfoundland was the dominant force.
However that pattern appeared to have only been repeated occasionally in recent decades.
"Now the southern current has taken over, it's really a drastic change," Schubert told AFP, pointing to the evidence of the shift towards warmer water in the northwest Atlantic.
The research was based on nitrogen isotope signatures in 700 year old coral reefs on the ocean floor, which feed on sinking organic particles.
While water pushed by the Gulfstream is salty and rich in nutrients, the colder Arctic waters carried by the Labrador current contain fewer nutrients.
Changes could be dated because of the natural growth rings seen in corals.
"The researchers suspect there is a direct connection between the changes in oceanic currents in the North Atlantic and global warming caused by human activities.
continuesClimate change to continue to year 3000 in best case scenarios: research
January 9, 2011
New research indicates the impact of rising CO2 levels in the Earth's atmosphere will cause unstoppable effects to the climate for at least the next 1000 years, causing researchers to estimate a collapse of the West Antarctic ice sheet by the year 3000, and an eventual rise in the global sea level of at least four metres.
The study, to be published in the Jan. 9 Advanced Online Publication of the journal Nature Geoscience, is the first full climate model simulation to make predictions out to 1000 years from now. It is based on best-case, 'zero-emissions' scenarios constructed by a team of researchers from the Canadian Centre for Climate Modelling and Analysis (an Environment Canada research lab at the University of Victoria) and the University of Calgary.
"We created 'what if' scenarios," says Dr. Shawn Marshall, Canada Research Chair in Climate Change and University of Calgary geography professor.
"What if we completely stopped using fossil fuels and put no more CO2 in the atmosphere? How long would it then take to reverse current climate change trends and will things first become worse?" The research team explored zero-emissions scenarios beginning in 2010 and in 2100.
The Northern Hemisphere fares better than the south in the computer simulations, with patterns of climate change reversing within the 1000-year timeframe in places like Canada. At the same time parts of North Africa experience desertification as land dries out by up to 30 percent, and ocean warming of up to 5°C off of Antarctica is likely to trigger widespread collapse of the West Antarctic ice sheet, a region the size of the Canadian prairies.
Researchers hypothesize that one reason for the variability between the North and South is the slow movement of ocean water from the North Atlantic into the South Atlantic. "The global ocean and parts of the Southern Hemisphere have much more inertia, such that change occurs more slowly," says Marshall. "The inertia in intermediate and deep ocean currents driving into the Southern Atlantic means those oceans are only now beginning to warm as a result of CO2 emissions from the last century.
The simulation showed that warming will continue rather than stop or reverse on the 1000-year time scale."
http://www.npr.org/templates/story/stor ... Id=9162438[hilite]It turns out that two-thirds of world's largest cities — cities with more than five million people — are at least partially in these low areas. [/hilite]That's important, because people are increasingly moving to cities.
Once the Amazon rainforests burn down things should start to get interesting.Tero wrote:I'm selling all my beach front property now.
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