December 20, 2006, 4:54 AM CT

Tropical Glaciers Vanishing Dramatically!

Not just the poles, the Equator is having its turn now! The global warming seems to be having its impact on the Equator now. Rivers of ice at the Equator are found to be melting away in this new century.

The great glaciers of Mount Kenya are found to have retreated through years, shrinking to white stains on the rocky landscapes of the 16,897-foot peak.

With the tropical glaciers, some 200 miles due south of the Mount Kilimanjaro are found to be disappearing astonishingly, to the west, in the heart of equatorial Africa, the ice caps atop Uganda's Rwenzoris are shrinking fast.

Almost every glacier of more than 300 of those studied worldwide is retreating dramatically! This is published in the journal Geophysical Research Letters' October issue by international glaciologists.

They think that this worldwide phenomenon is 'essentially a response to post-1970 global warming!'.........

Posted by: Tyler      Permalink         Source

December 13, 2006, 6:27 PM CT

Soil Nutrition And Carbon Sequestration

USDA Forest Service (FS) scientists from the FS Southern Research Station (SRS) unit in Research Triangle Park, NC, along with colleagues from Duke University, published two papers in The Proceedings of the National Academy of Science (PNAS) that provide a more precise understanding of how forests respond to increasing atmospheric concentrations of carbon dioxide (CO2), the major greenhouse gas driving climate change.

Building on preliminary studies reported in Nature, the researchers found that trees can only increase wood growth from elevated CO2 if there is enough leaf area to support that growth. Leaf area, in turn, is limited by soil nutrition; without adequate soil nutrition, trees respond to elevated CO2 by transferring carbon below ground, then recycling it back to the atmospheric through respiration.

"With sufficient soil nutrition, forests increase their ability to tie up, or sequester carbon in woody biomass under increasing atmospheric CO2 concentrations," says Kurt Johnsen, SRS researcher involved in the project. "With lower soil nutrition, forests still sequester carbon, but cannot take full advantage increasing CO2 levels. Due to land use history, many forests are deficient in soil nutrition, but forest management -- including fertilizing with nitrogen -- can greatly increase growth rate and wood growth responses to elevated atmospheric CO2".........

Posted by: Tyler      Permalink         Source

December 11, 2006, 9:36 PM CT

Plant One Tree And Save The Earth

Can planting a tree stop the sea level from rising, the ice caps from melting and hurricanes from intensifying?

A new study says that it depends on where the trees are planted. It cautions that new forests in mid- to high-latitude locations could actually create a net warming. It also confirms the notion that planting more trees in tropical rainforests could help slow global warming worldwide.

In the first study to investigate the combined climate and carbon-cycle effects of large-scale deforestation in a fully interactive three-dimensional climate-carbon model, researchers from Lawrence Livermore National Laboratory, Carnegie Institution and Universite Montpellier II observed that global forests actually produce a net warming of the planet.

The study provides a holistic view of the deforestation issue. "This is the first comprehensive assessment of the deforestation problem" said Govindasamy Bala, lead author of the research that will be presented on Dec. 15 at the American Geophysical Society annual meeting in San Francisco.

The models calculated the carbon/climate interactions and took into account the physical climate effect and the partitioning of the carbon dioxide release from deforestation among land, atmosphere and ocean.

Forests affect climate in three different ways: they absorb the greenhouse gas carbon dioxide from the atmosphere and help to keep the planet cool; they evaporate water to the atmosphere and increase cloudiness, which also helps keep the planet cool; and they are dark and absorb a lot of sunlight, warming the Earth. Climate change mitigation strategies that promote planting trees have taken only the first effect into account.........

Posted by: Tyler      Permalink         Source

December 11, 2006, 4:53 AM CT

Birth Pangs of Earth's Crust

Forsyth and Saal, professors of geology at Brown University, were returning from a research cruise to map an area of seafloor near the Galapagos Islands last April, along with seven Brown graduate students and four undergraduates. The cruise route took the ship right by a highly studied section of the mid-ocean ridge called the East Pacific Rise. The area had experienced an episode of seafloor spreading in 1991 and was being closely monitored as part of the RIDGE2000 program sponsored by the National Science Foundation.

A team of scientists headed by Maya Tolstoy, a geologist at Columbia's Earth Institute, had placed an array of ocean-bottom seismometers (OBS) at the spot in 2003 and collected data from the vibration-recording devices at least once a year. With ship-time at a premium, it's common for a research ship to make a quick stop to download such data.

The task should have been simple. The seismometers are anchored to the seafloor by a mechanism that will release them and allow them to float to the surface when triggered by an acoustic signal. The crew and scientists scoop up the microwave-oven-sized devices and return them to shore, replacing them with new ones that will monitor seismic activity for the next year. It's uncommon for an OBS to be lost due to mechanical malfunction.........

Posted by: Tyler      Permalink         Source

December 11, 2006, 4:38 AM CT

Isotopes Score One for Traditional Theory

One great beauty of plate tectonics theory is that it explains so a number of geological phenomena at one time. But plate tectonics could not explain the location of a number of volcanic islands - Hawaii, the Azores or the Galapagos Islands, often called "hotspots" - far from the edge of tectonic plates. To deal with those observations, geologists invoked the concept of "plumes" - areas where buoyant sections of mantle material rose, melted and developed into concentrated upwellings of magma, forming seamounts and island chains.

A running battle has evolved over the last 30 years concerning hotspots: One camp claims it is not necessary to invoke mantle plumes to explain such volcanic islands, and the other camp - a sizeable portion of the geological community - supports mantle plumes as the most internally consistent explanation for a wide variety of data.

A study published this week in the journal Nature raises the bar for plume opponents by finding a close connection between modeled and observed ratios of uranium-series isotopes across eight island locations. The study strongly supports upwelling of mantle material as the source of these islands. Moreover, the detailed data allow scientists to estimate the change in temperature, speed and size of mantle plumes at the locations studied.........

Posted by: Tyler      Permalink         Source

December 5, 2006, 8:56 PM CT

Southern Ocean Could Slow Global Warming

The Southern Ocean may slow the rate of global warming by absorbing significantly more heat and carbon dioxide than previously thought, as per new research.

The Southern Hemisphere westerly winds have moved southward in the last 30 years. A new climate model predicts that as the winds shift south, they can do a better job of transferring heat and carbon dioxide from the surface waters surrounding Antarctica into the deeper, colder waters.

The new finding surprised the scientists, said lead researcher Joellen L. Russell. "We think it will slow global warming. It won't reverse or stop it, but it will slow the rate of increase."

The new model Russell and her colleagues developed provides a realistic simulation of the Southern Hemisphere westerlies and Southern Ocean circulation.

Prior climate models did not have the winds properly located. In simulations of present-day climate, those models distorted the ocean's response to future increases in greenhouse gases.

"Because these winds have moved poleward, the Southern Ocean around Antarctica is likely to take up 20 percent more carbon dioxide than in a model where the winds are poorly located," said Russell, an assistant professor of geosciences at The University of Arizona in Tucson.........

Posted by: Tyler      Permalink         Source

December 5, 2006, 8:37 PM CT

Measuring Carbon Without Destroying Trees

USDA Forest Service (FS) scientists have provided the first proof of concept for a method that allows researchers to study below-ground carbon allocation in trees without destroying them. In the latest issue of the journal Plant, Cell and Environment, Kurt Johnsen and fellow scientists at the FS Southern Research Station unit in Research Triangle Park, NC, describe a reversible, non-destructive chilling method that stops the movement of carbon into root systems.

The photosynthetic process of plants has been estimated to account for almost half of the carbon circulating in the Earth's systems. Reliable data has been developed on carbon cycling in the above-ground processes of trees, but how much carbon is actually moved and stored below the ground has not yet been determined. Most methods to study below-ground processes involve destroying the roots as well as the mycorrhizal communities that live symbiotically with root systems.

"Below-ground carbon allocation is one of the least understood processes in tree physiology," says Johnsen. "Being able to accurately measure it is essential for modeling forest and ecosystem productivity and carbon sequestration, but most methods disturb the root-mycorrhizal continuum that plays an essential role in nutrient transport".........

Posted by: Tyler      Permalink         Source

December 5, 2006, 4:59 AM CT

Rise In California Temperatures

Increasing temperatures in California during the next 45 years could negatively affect the amount of almonds, walnuts, oranges, avocados and table grapes that Americans put on their tables.

As per new research in the journal Agricultural and Forest Meteorology, production losses in some of California's most popular crops could be as high as 40 percent by mid-century.

In the study, scientists from Lawrence Livermore National Laboratory reviewed the impact of climate change on six major perennial crops in California: wine grapes, almonds, table grapes, oranges, walnuts and avocados. Each of these crops is typically planted only once every 25-40 years. However, so that climate can change considerably in the lifetime of individual vines or trees.

Using more than 20 climate models, the authors assessed the response of these crops to projected changes in temperature (an increase of 2 degrees to 4 degrees Celsius) and precipitation.

"Climate change should be an important factor in selecting perennial varieties and deciding whether and where they should be planted in California," said David Lobell, the lead author of the paper who collaborated with researchers at the Carnegie Institution, Stanford University and UC Merced. "This study indicates that warmer temperatures will tend to reduce yields of these crops in their current locations."........

Posted by: Tyler      Permalink         Source

December 1, 2006, 4:27 AM CT

Seagrass ecosystems at a 'global crisis'

An international team of researchers is calling for a targeted global conservation effort to preserve seagrasses and their ecological services for the worlds coastal ecosystems, as per an article reported in the recent issue of Bioscience, the journal of the American Institute of Biological Sciences (AIBS).

The article "A Global Crisis for Seagrass Ecosystems" cites the critical role seagrasses play in coastal systems and how costal development, population growth and the resulting increase of nutrient and sediment pollution have contributed to large-scale losses worldwide.

"Seagrasses are the coal mine canaries of coastal ecosystems," said co-author Dr. William Dennison of the University of Maryland Center for Environmental Science. "The fate of seagrasses can provide resource managers advance signs of deteriorating ecological conditions caused by poor water quality and pollution."

Among its findings, the study analyzed an apparent disconnect between the scientific communitys concerns over seagrass habitat and its coverage in the popular media. While recent studies rank seagrass as one of the most valuable habitat in coastal systems, media coverage of other habitats including salt marshes, mangroves and coral reefs receive 3 to 100-fold more media attention than seagrass systems.........

Posted by: Jessica      Permalink         Source

December 1, 2006, 4:23 AM CT

Potential For Biodiversity Management

While global protected areas, including nature reserves, parks, and areas protected by treaties, protect some aspects of biodiversity, shortcomings remain: the areas only cover certain habitats and local people often resent their formal management. Natural sacred sites exist in many countries around the world, with communities often sharing and managing sites that are not under formal protection. Such sites cover a wide variety of habitats and are often located in biodiversity hotspots. Shonil Bhagwat (Natural History Museum, London and University of Oxford) and Claudia Rutte (University of Bern, Switzerland) propose that such habitats should be included in biodiversity management.

Although 23 percent of Earth's tropical forests are formally protected, only 8 percent of cropland and natural vegetation mosaic habitats receive the same protection. Natural sacred sites, protected by local traditions, are often situated within agricultural landscapes, providing corridors for wildlife. These sites come in many forms, including burial grounds and sites of ancestral deity worship, and often include organisms not protected in more formal settings. For example, sacred groves in the Koduga district of Karnataka state, India, have relict populations of certain threatened tree species that are not found in formal protected areas.........

Posted by: Tyler      Permalink         Source