Tag Archives: climate warming

Dwindling waterways challenge desert fish in warming world

One of Arizona’s largest watersheds – home to many native species of fish already threatened by extinction – is providing a grim snapshot of what could happen to watersheds and fish in arid areas around the world as climate warming occurs.

New research by University of Washington and Ohio State University scientists suggests that, by 2050, the Verde River Basin in Arizona will have up to one-fifth more streams dry up each season and at least a quarter more days with no water flow, a problem when fish are trying to reach spawning habitats and refuges where water still remains. (more…)

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Lungs of the Planet Reveal Their True Sensitivity to Global Warming

Tropical rainforests are often called the “lungs of the planet” because they generally draw in carbon dioxide and breathe out oxygen. 

But the amount of carbon dioxide that rainforests absorb, or produce, varies hugely with year-to-year variations in the climate.

In a paper published online (Feb 6 2013) by the journal Nature, a team of climate scientists from the University of Exeter, the Met Office-Hadley Centre and the NERC Centre for Ecology & Hydrology, has shown that these variations reveal how vulnerable the rainforest is to climate change. (more…)

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Climate Warming Unlikely to Cause Near-Term Extinction of Ancient Amazon Trees, Study Says

ANN ARBOR — A new genetic analysis has revealed that many Amazon tree species are likely to survive human-caused climate warming in the coming century, contrary to previous findings that temperature increases would cause them to die out.

However, the authors of the new study warn that extreme drought and forest fires will impact Amazonia as temperatures rise, and the over-exploitation of the region’s resources continues to be a major threat to its future. Conservation policy for the Amazon should remain focused on reducing global greenhouse-gas emissions and preventing deforestation, they said. (more…)

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Not-So-Permanent Permafrost

MENLO PARK, Calif. — As much as 44 billion tons of nitrogen and 850 billion tons of carbon stored in arctic permafrost, or frozen ground, could be released into the environment as the region begins to thaw over the next century as a result of a warmer planet according to a new study led by the U.S. Geological Survey. This nitrogen and carbon are likely to impact ecosystems, the atmosphere, and water resources including rivers and lakes. For context, this is roughly the amount of carbon stored in the atmosphere today.

The release of carbon and nitrogen in permafrost could exacerbate the warming phenomenon and will impact water systems on land and offshore according to USGS scientists and their domestic and international collaborators. The previously unpublished nitrogen figure is useful for scientists who are making climate predictions with computer climate models, while the carbon estimate is consistent and gives more credence to other scientific studies with similar carbon estimates. (more…)

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Woolly Mammoth Extinction Has Lessons for Modern Climate Change

Although humans and woolly mammoths co-existed for millennia, the shaggy giants disappeared from the globe between 4,000 and 10,000 years ago, and scientists couldn’t explain until recently exactly how the Flintstonian behemoths went extinct.

In a paper published June 12 in the journal Nature Communications, UCLA researchers and colleagues reveal that not long after the last ice age, the last woolly mammoths succumbed to a lethal combination of climate warming, encroaching humans and habitat change — the same threats facing many species today. (more…)

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Study Indicates Hail May Disappear From Colorado’s Front Range by 2070

Summertime hail could all but disappear from the eastern flank of Colorado’s Rocky Mountains by 2070, says a new study by the National Oceanic and Atmospheric Administration, the University of Colorado Boulder’s Cooperative Institute for Research in Environmental Sciences and the National Center for Atmospheric Research.

Less hail damage could be good news for gardeners and farmers, said lead author Kelly Mahoney, a research scientist at CIRES, but a shift from hail to rain can also mean more runoff, which could raise the risk of flash floods. “In this region of elevated terrain, hail may lessen the risk of flooding because it takes awhile to melt,” Mahoney said. “Decision makers may not want to count on that in the future.” (more…)

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Uncertain Future for Joshua Trees Projected with Climate Change

FLAGSTAFF, Ariz. — Temperature increases resulting from climate change in the Southwest will likely eliminate Joshua trees from 90 percent of their current range in 60 to 90 years, according to a new study led by U.S. Geological Survey ecologist Ken Cole.

The research team used models of future climate, an analysis of the climatic tolerances of the species in its current range, and the fossil record to project the future distribution of Joshua trees. The study concludes that the species could be restricted to the northernmost portion of its current range as early as the end of this century. Additionally, the ability of Joshua trees to migrate via seed dispersal to more suitable climates may be severely limited. (more…)

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Water Flowing Through Ice Sheets Accelerates Warming, Could Speed Up Ice Flow, Says New Study

Melt water flowing through ice sheets via crevasses, fractures and large drains called moulins can carry warmth into ice sheet interiors, greatly accelerating the thermal response of an ice sheet to climate change, according to a new study involving the University of Colorado at Boulder.

The new study showed ice sheets like the Greenland Ice Sheet can respond to such warming on the order of decades rather than the centuries projected by conventional thermal models. Ice flows more readily as it warms, so a warming climate can increase ice flows on ice sheets much faster than previously thought, said the study authors. (more…)

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