Climate

In 1100's, temperatures in Greenland dropped 7 degrees F in 80 years; cause of Viking's departure?
May 31, 2011 06:40 AM - Reuters

A cold snap in Greenland in the 12th century may help explain why Viking settlers vanished from the island, scientists said on Monday. The report, reconstructing temperatures by examining lake sediment cores in west Greenland dating back 5,600 years, also indicated that earlier, pre-historic settlers also had to contend with vicious swings in climate on icy Greenland. "Climate played (a) big role in Vikings' disappearance from Greenland," Brown University in the United States said in a statement of a finding that average temperatures plunged 4 degrees Celsius (7F) in 80 years from about 1100. Such a shift is roughly the equivalent of the current average temperatures in Edinburgh, Scotland, tumbling to match those in Reykjavik, Iceland. It would be a huge setback to crop and livestock production.

Melting ice roads in Arctic could have big impact
May 30, 2011 08:08 AM - Timothy Gardner, Reuters, WASHINGTON

Global warming will likely open up coastal areas in the Arctic to development but close vast regions of the northern interior to forestry and mining by mid-century as ice and frozen soil under temporary winter roads melt, researchers said. Higher temperatures have already led to lower summer sea ice levels in the Arctic and the melting has the potential to increase access for fishermen, tourists and oil and natural gas developers to coastal regions in coming decades. The melting has also led to hopes that shorter Arctic shipping routes between China and Europe will open. The Arctic is increasingly a region of deep strategic importance to the United States, Russia and China for its undiscovered resource riches and the potential for new shipping lanes. The U.S. Geological Survey says that 25 percent of the world's undiscovered oil and natural gas lies in the Arctic. But the warming also will likely melt so-called "ice roads", the temporary winter roads developers now use to access far inland northern resources such as timber, diamonds and minerals, according to a study published on Sunday in the journal Nature Climate Change.

Did Quiet Sun Cause Little Ice Age After All?
May 27, 2011 10:36 AM - Govert Schilling, Science AAAS

BOSTON—For decades, astronomers and climatologists have debated whether a prolonged 17th century cold spell, best documented in Europe, could have been caused by erratic behavior of the sun. Now, an American solar physicist says he has new evidence to suggest that the sun was indeed the culprit.

Two Greenland Glaciers Lose Enough Ice to Fill Lake Erie
May 25, 2011 10:03 AM - Editor, Science Daily

ScienceDaily (May 24, 2011) — A new study aimed at refining the way scientists measure ice loss in Greenland is providing a "high-definition picture" of climate-caused changes on the island. And the picture isn't pretty. In the last decade, two of the largest three glaciers draining that frozen landscape have lost enough ice that, if melted, could have filled Lake Erie.

Drought in China significantly cuts hydroelectric output
May 25, 2011 06:07 AM - David Stanway, Reuters, BEIJING

The worst drought to hit central China in half a century has brought water levels in some of the country's biggest hydropower producing regions to critical levels and could exacerbate electricity shortages over the summer. The official Xinhua news agency said on Wednesday that the water level at the world's biggest hydropower plant at the Three Gorges Dam in Hubei province has fallen to 152.7 meters, well below the 156-m mark required to run its 26 turbines effectively. Total capacity at the Three Gorges hydropower project amounts to 18.2 gigawatts, the equivalent of about 15 third-generation nuclear reactors and more than a third of Hubei's total. It generated 84.4 billion kilowatt-hours of electricity in 2010, delivering power as far afield as Shanghai on the eastern coast. The water level is expected to fall further to around 145 meters by June 10, when planned discharges are scheduled to end. The drought has struck at the time of year when China's hydropower output would normally surge. Hydro output bottoms out in January and February and peaks over the summer. During six months of last year, from May to October, 20 percent of China's electricity generation was hydropower.

Waste Heat Recovery: The Next Wave of Clean Tech
May 24, 2011 03:32 PM - Jason Gold, CEO, KGRA Energy, LP

The terms renewable energy and clean technology conjure up images of photovoltaic panels baking in the desert sun, wind turbines rotating lazily in the wind, and large dams generating hydro-power. However, there is another important and growing clean energy technology that the average consumer hasn't heard of yet: waste heat recovery. Waste heat recovery employs a process that has been around since the 1960s called the organic Rankine cycle (ORC), which easily integrates into existing manufacturing infrastructures. ORC units capture heat that is currently being released into the atmosphere and converts it into useable CO2-free electricity. This technology has a small footprint, approximately the size of a tractor trailer flatbed and interest in systems that use this energy generating skid is on the rise as companies look to maximize the efficiency of existing investments and infrastructures. The market for waste heat recovery is virtually limitless. According to researchers at University California Berkley, the U.S. currently consumes about 100 quadrillion BTUs of energy per year. However, between 55 and 60 quadrillion BTUs are currently vented into the atmosphere as waste heat. With ORC technology these emissions are harnessed on-site to generate useable CO2-free electricity that is fed directly back into a manufacturing process. Pulp and paper, lumber, refinery, cement and power plant operations are especially well-suited for waste heat recovery systems since they consume large amounts of electricity and maintain consistent waste heat streams with temperatures between 400° and 800°F.

Farm states suffer expanded drought
May 20, 2011 06:29 AM - Carey Gillam, Retuers, KANSAS CITY, Missouri

A dire drought that has plagued Texas and parts of Oklahoma expanded across the key farming state of Kansas over the last week, adding to struggles of wheat farmers already dealing with weather-ravaged fields. Harvest in Kansas, the top U.S. wheat-growing state, is set to begin within weeks. But a report issued Thursday by a consortium of climatologists said the three most severe levels of drought spread across the state over the last week, with the most dire conditions concentrated in the key wheat-growing south-central and southwest parts. "It is pretty bad," said Kansas state climatologist Mary Knapp. "For a lot of these areas... the last significant rainfall was in July of last year." Kansas now has 50 percent of the state suffering severe levels of drought or worse, up from 41 percent last week, according to the Drought Monitor report. Just three months ago, less than 4 percent of Kansas was suffering severe drought or worse. The drought is eroding production potential at a time when every bushel counts.

High Atmospheric CO2 Levels May Cause Mass Extinctions in the Oceans
May 19, 2011 09:20 AM - David A Gabel, ENN

One of the greatest causes of global climate change is the human emissions of greenhouse gases, specifically carbon dioxide (CO2). These emissions are released into the atmosphere, but much of it gets absorbed into the world's oceans. A new study, published in the Proceedings of the National Academy of Sciences, looked at prehistoric ocean sediment and found a disturbing trend. Periods of high CO2 concentrations have historically coincided with mass extinctions of marine organisms.

The Salty Seas of Earth
May 19, 2011 08:16 AM - Andy Soos, ENN

Final preparations are under way for the June 9 launch of the international Aquarius/SAC-D observatory. The mission's primary instrument, Aquarius, will study interactions between ocean circulation, the water cycle and climate by measuring ocean surface salinity. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L). In addition to Aquarius, the observatory carries seven other instruments that will collect environmental data for a wide range of applications, including studies of natural hazards, air quality, land processes and epidemiology. Although the vast majority of seawater has a salinity of between 3.1% and 3.8%, seawater is not uniformly saline throughout the world. Where mixing occurs with fresh water runoff from river mouths or near melting glaciers, seawater can be substantially less saline. The most saline open sea is the Red Sea, where high rates of evaporation, low precipitation and river inflow, and confined circulation result in unusually salty water. The salinity in isolated bodies of water (for example, the Dead Sea) can be considerably greater still.

Louisiana flooding continues, peak nears
May 18, 2011 06:26 AM - Kristen Hays, Reuters, LIVONIA, Louisiana

Floodwater released from a key Mississippi River spillway surged through the Louisiana bayou on Tuesday, and levees protecting the state's two biggest cities held as river flows neared their peak. The U.S. Army Corps of Engineers opened the Morganza Spillway on Saturday in an effort to spare the downstream cities of New Orleans and Baton Rouge from the Mississippi River's record flooding. Towns and crop lands along the Atchafalaya River basin that are in the path of the diverted floodwaters could see as much as 20 feet of water in coming days. Flooding has reached places like Butte LaRose and St. Landry Parish at the northern end of the basin, putting some houses underwater. In towns like Krotz Springs and Morgan City to the south, construction crews have erected miles of flood barriers, assisted by National Guard troops and even prison inmates, as they await the rising water. The floodwater is making its way south from the spillway more slowly than the Corps originally forecast, in part due to drought-parched soil that is soaking up some of the water, Louisiana Governor Bobby Jindal said at a press briefing.

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