A new study of possible links between climate and geophysics on Earth and similar planets finds that prolonged heating of the atmosphere can shut down plate tectonics and cause a planet's crust to become locked in place. "The heat mandatory goes far beyond anything we expect from human-induced climate change, but things like volcanic activity and changes in the sun's luminosity could lead to this level of heating," said lead author Adrian Lenardic, associate professor of Earth science at Rice University. "Our goal was to establish an upper limit of naturally generated climate variation beyond which the entire solid planet would respond"........

New evidence, more questions. That's the thumbnail of the first new data reported in 10 years from Monte Verde, the earliest known human settlement in the Americas. Evidence from the archaeological site in southern Chile confirms Monte Verde is the Americas earliest known settlement and is consistent with the idea that early human migration occurred along the Pacific Coast more than 14,000 years ago, but questions remain about just how rapidly that migration occurred........

Chile's Chaiten Volcano is shown spewing ash and smoke (centre left of image) into the air for hundreds of km over Argentina's Patagonia Plateau in this Envisat image acquired on 5 May 2008. The 1000 m-high volcano had been dormant for thousands of years before erupting on 2 May, causing the evacuation of thousands. Chaiten Volcano is located in southern Chile 10 km northeast of the town of Chaiten on the Gulf of Corcovado........

HIGH gasoline prices could lead to a dramatic saving in US greenhouse-gas emissions. Thats the conclusion of economists in the US, who suggest high fuel prices are turning consumers off SUVs and onto smaller, more fuel-efficient vehicles. Whats more, car owners are predicted to cut back on driving in order to save money. Together, these changes in consumer behaviour could make an important dent in the US contribution to global warming, reducing annual carbon dioxide emissions by tens of millions of tonnes per year. The impact will be dramatic, says Chris Knittel, an economist at the University........

Methyl bromide, an odorless, colorless gas used as an agricultural pesticide, was introduced in the 1980s as an effective way to control weeds and increase fruit yields. Agricultural production nurseries around the world relied on methyl bromide (MB) to produce healthy plants for export and domestic sales. In 2000, the widely used pesticide was classified as an ozone-depleting substance, and in 2005 MB was banned in the United States and all European Union countries........

Computer analyses of global climate have consistently overstated warming in Antarctica, concludes new research by researchers at the National Center for Atmospheric Research (NCAR) and Ohio State University. The study can help researchers improve computer models and determine if Earth's southernmost continent will warm significantly this century, a major research question because of Antarctica's potential impact on global sea-level rise........

Add university research to the long list of human activities contributing to global warming. Herv Philippe, a Universit de Montral professor of biochemistry, is a committed environmentalist who observed that his own research produces 44 tonnes of CO2 per year. The average American citizen produces 20 tonnes........

The Earth's oceans play a vital role in the carbon cycle, making it imperative that we understand marine biological activity enough to predict how our planet will react to the extra 25 000 million tonnes of carbon dioxide humans are pumping into the atmosphere annually. The colour of oceanic seawater depends largely on the number of microscopic phytoplankton, marine plants that live in the well-lit surface layer. Just like land-based plants, phytoplankton accumulate carbon dioxide during photosynthesis and store it in their tissues, making them potentially important carbon sinks........

Russian and American researchers have discovered that the rising temperature of the world's largest lake, located in frigid Siberia, shows thatandnbsp;this region is responding strongly to global warming. Drawing on 60 years of long-term studies of Russia's Lake Baikal, Stephanie Hampton, an ecologist and deputy director of the National Center for Ecological Analysis and Synthesis (NCEAS) in Santa Barbara, Calif., and Marianne Moore,andnbsp;a biologist at Wellesley College in Wellesley, Mass., along with four other scientists, report their results on-line today in the journal Global Change Biology........

The Earth's crust is, on global average around 40 kilometres deep. In relation to the total diameter of the Earth with approx. 12800 kilometres this appears to be rather shallow, but precisely these upper kilometres of the crust, the human habitat, is of special interest for us. Europe's crust shows an astonishing diversity: for example the crust under Finland is as deep as one only expects for crust under a mountain range such as the Alps. It is also amazing that the crust under Iceland and the Faroer-Islands is considerably deeper than a typical oceanic crust. This is explained by M. Tesauro und M. Kaban from GeoForschungsZentrum Potsdam (GFZ) and S. Cloetingh from the Vrije Universiteit in Amsterdam in a recent publication in the renowned scientific journal "Geophysical Research Letters". GFZ is the German Research Centre for Geosciences and a member of the Helmholtz Association........

New University of Colorado at Boulder calculations indicate the record low minimum extent of sea ice across the Arctic last September has a three-in-five chance of being shattered again in 2008 because of continued warming temperatures and a preponderance of younger, thinner ice. The forecast by scientists at CU-Boulder's Colorado Center for Astrodynamics Research is based on satellite data and temperature records and indicates there is a 59 percent chance the annual minimum sea ice record will be broken this fall for the third time in five years. Arctic sea ice declined by roughly 10 percent in the past decade, culminating in a record 2007 minimum ice cover of 1.59 million square miles. That broke the 2005 record by 460,000 miles -- an area the size of Texas and California combined........

Researchers at the Georgia Institute of Technology have discovered a new climate pattern called the North Pacific Gyre Oscillation. This new pattern explains, for the first time, changes in the water that are important in helping commercial fishermen understand fluctuations in the fish stock. They're also finding that as the temperature of the Earth is warming, large fluctuations in these factors could help climatologists predict how the oceans will respond in a warmer world. The research appears in the April 30 edition of the journal Geophysical Research Letters........

The Dust Bowl drought of the 1930s was one of the worst environmental disasters of the Twentieth Century anywhere in the world. Three million people left their farms on the Great Plains during the drought and half a million migrated to other states, almost all to the West. But the Dust Bowl drought was not meteorologically extreme by the standards of the Nineteenth and Twentieth Centuries. Indeed the 1856-65 drought may have involved a more severe drop in precipitation. It was the combination of drought and poor land use practice that created the environmental disaster........

MIT Professor Dara Entekhabi will lead the science team designing a NASA satellite mission to make global soil moisture and freeze/thaw measurements, data essential to the accuracy of weather forecasts and predictions of global carbon cycle and climate. NASA announced recently that the Soil Moisture Active-Passive mission (SMAP) is scheduled to launch December 2012........

Recent additions to the premier collection of Southern Ocean sediment cores at Florida State Universitys Antarctic Marine Geology Research Facility will give international researchers a close-up look at fluctuations that occurred in Antarcticas ice sheet and marine and terrestrial life as the climate cooled considerably between 20 and 14 million years ago........

In the first experiment involving a natural environment, researchers at Brown University have shown that richer plant diversity significantly enhances an ecosystem's productivity. The finding underscores the benefits of biodiversity, such as capturing carbon dioxide, a main contributor to global warming........

HOUSTON, April 24, 2008 After finding more than 300 surface faults in Harris County, a University of Houston geologist now has information that could be vitally useful to the regions builders and city planners. This information the most accurate and comprehensive of its kind was discovered by Shuhab Khan, assistant professor of geology, and Richard Engelkemeir, a geology Ph.D. student, using advanced radar-like laser technology. Eventhough geologists have long known of the existence of faults in Southeast Texas, only recently have UH scientists produced a comprehensive map pinpointing the locations of the faults. A Houston-area map showing active surface faults is available at http://www.uh.edu/news-events/archive/nr/2008/04april/geological-faultsph.html........

A much-discussed idea to offset global warming by injecting sulfate particles into the stratosphere would have a drastic impact on Earth's protective ozone layer, new research concludes. The study, led by Simone Tilmes of the National Center for Atmospheric Research (NCAR) in Boulder, Colo., warns that such an approach would delay the recovery of the Antarctic ozone hole by decades and cause significant ozone loss over the Arctic........

To the surprise of a number of, the earthquake on April 18, 2008, about 120 miles east of St. Louis, originated in the Wabash Valley Fault and not the better-known and more-dreaded New Madrid Fault in Missouri's bootheel. The concern of Douglas Wiens, Ph.D., and Michael Wysession, Ph.D., seismologists at Washington University in St. Louis, is that the New Madrid Fault may have seen its day and the Wabash Fault is the new kid on the block........

The Antarctic deep sea gets colder, which might stimulate the circulation of the oceanic water masses. This is the first result of the Polarstern expedition of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association that has just ended in Punta Arenas/Chile. At the same time satellite images from the Antarctic summer have shown the largest sea-ice extent on record. In the coming years autonomous measuring buoys will be used to find out whether the cold Antarctic summer induces a new trend or was only a "slip"........