Category: Drought

So how, exactly, does global warming kill forests?

Global warming has killed half a billion trees across the U.S.

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Global warming is killing forests around the world. @bberwyn photo.

Staff Report

Scientists tracking massive forest die-offs say a new study may help forest managers learn how to predict which trees will succumb to global warming — and what the implications are for the global carbon balance.

“There are some common threads that we might be able to use to predict which species are going to be more vulnerable in the future,” said University of Utah biologist William Anderegg, explaining that recent tree-killing droughts in the western U.S. were marked more by elevated temperature than by a lack of rainfall.

“These widespread tree die-offs are a really early and visible sign of climate change already affecting our landscapes,” Anderegg said.

More stories on global warming and forests:

Continue reading “So how, exactly, does global warming kill forests?”

Global warming is already affecting wine production

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Wine grapes at harvest time in southern France. @bberwyn photo.

NASA, Harvard scientists study wine harvest dates in cool-weather countries

Staff Report

Global warming is changing centuries-old climate patterns that are crucial for wine production in cool-weather regions, a new study from NASA and Harvard concludes. After analyzing climate records and grape harvesting dates from 1600 to 2007, the scientists found that harvests started happening much earlier during the second half of the 20th century.

These shifts were caused by changes in the connection between climate and harvest timing. Between 1600 and 1980, earlier harvests were linked to years with warmer and drier conditions during spring and summer. After that, global warming caused earliers harvests in years without droughts. Continue reading “Global warming is already affecting wine production”

Climate: U.S. West very dry in February

Very dry across the West in February 2016.
Very dry across the West in February 2016.

Where’s El Niño?

Staff Report

El Niño didn’t exactly go gangbusters in southwest Colorado last month, where the key river basins received only about 35 percent of average February precipitation. Statewide mountain precipitation was only slightly better, at 56 percent of normal.

“February in the mountains of Colorado is typically a slightly drier month than compared to say, April. But a dry February like this could have big ramifications should April and May not pan out” said Brian Domonkos, Snow Survey Supervisor with the Natural Resources Conservation Service. Continue reading “Climate: U.S. West very dry in February”

Climate: Study sees global warming fingerprint on long-running drought in Mediterranean region

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Researchers in the Mediterranean region are trying to guard against climate change impacts by cultivating numerous varieties of native olives to determine which might best be able to withstand heatwaves and drought. @bberwyn photo.

Current regional dry spell appears to be the most severe in more than 900 years

Staff Report

The Mediterranean region may already be feeling the impacts of human-caused climate change, according to a new tree ring study that compared an ongoing drought in the region with historic climate conditions.

Based on the findings, NASA scientists concluded the current drought — spread across Cyprus, Israel, Jordan Lebanon, Palestine, Syria and Turkey — is the worst in at least 900 years. Nearly all climate models project that global warming will dry up the Mediterranean region. Continue reading “Climate: Study sees global warming fingerprint on long-running drought in Mediterranean region”

Climate: El Niño not a drought-buster for California yet

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Exceptional drought is still widespread across California with a few more months of the rainy season ahead.

Will spring deliver big rains?

Staff Report

Although there are still a few months left in the rainy season, this year’s El Niño hasn’t exactly been the drought buster California was hoping for. Thus far, plentiful precipitation in the northern part of state will go a long way toward replenishing reservoirs, but central and southern California have remained relatively dry.

The “exceptional drought” footprint is now spread across about 38 percent of the state, as compared to 45 percent three months ago, and precipitation in the key snowpack areas of the Sierra Nevada has been about average. Farther south, especially in the L.A. Basin, precipitation is still well below average for the rainy season to date.

That may be due to the fact that the distribution of warm water across the Pacific Ocean is quite different than during past El Niños that brought more widespread heavy precipitation to California. Continue reading “Climate: El Niño not a drought-buster for California yet”

Climate: This year’s El Niño has passed its peak, scientists say

Impacts expected for months to come

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This year’s El Niño will go down as one of the strongest on record

Staff Report

Meteorologists say the 2015-2016 El Niño has peaked, but it remains strong and will continue to influence global weather in the months ahead. With eastern and central tropical Pacific Ocean surface temperatures more than 2 degrees Celsius above average in late 2015, this El Niño will go down as one of the strongest on record, although it’s not clear if it was the strongest ever, according to the World Meteorological Organization.

For now, the outlook is that El Niño will fade during the next half year. As typically happens,  El Niño reached its peak ocean surface temperature during November and December, but those temperatures have since declined by about half a degree.

“We have just witnessed one of the most powerful ever El Niño events which caused extreme weather in countries on all continents and helped fuel record global heat in 2015,” said WMO Secretary General Petteri Taalas. “In meteorological terms, this El Niño is now in decline. But we cannot lower our guard as it is still quite strong and in humanitarian and economic terms, its impacts will continue for many months to come,” Taalas said. Continue reading “Climate: This year’s El Niño has passed its peak, scientists say”

Will global warming desiccate the Southwest?

‘A normal year in the Southwest is now drier than it once was’

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Will the Southwest’s life-giving rains fade away? @bberwyn photo.
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A federal climate assessment projects soaring temperatures for the Southwest.

Staff Report

A subtle long-term shift in atmospheric patterns driven by global warming could lead to longer and more intense droughts in the southwestern U.S. and other semi-arid regions. Most climate models suggest that that a belt of higher average pressure that now sits closer to the equator will move north. This high-pressure belt is created as air that rises over the equator moves poleward and then descends back toward the surface.

That shift may already be affecting the climate of the Southwest, as moisture-bearing weather patterns have become more rare in the region, according to a new study. Previous research has suggested that the region’s forests and fish and birds are in big trouble. In Australia, researchers are nearly certain that global warming was a factor in a record-breaking 2013 heatwave. A federal climate assessment released in 2013 also identified similar concerns for the Southwest.

“A normal year in the Southwest is now drier than it once was,” said Andreas Prein, a postdoctoral researcher at the National Center for Atmospheric Research who led the study. “If you have a drought nowadays, it will be more severe because our base state is drier.” Continue reading “Will global warming desiccate the Southwest?”