Environment: Is the Amazon rainforest near a tipping point?

A NASA photo taken from the International Space Station shows sunlight glinting off the Amazon River.

A NASA photo taken from the International Space Station shows sunlight glinting off the Amazon River.

Drought the main driver of destructive fires

By Staff Report

FRISCO — Longer droughts, land-use changes and wildfires may  be pushing parts of the Amazon rainforest toward an ecological tipping point, a team of scientists said after analyzing the effects of fire in a series of study plots.

The changes may abruptly increase tree mortality and change vegetation over large areas, the researchers said, pointing out that current Amazon forest models don’t include the impacts of wildfires. As a result, projections of future forest health tend to underestimate the amount of tree death and overestimate overall forest health, said Dr. Michael Coe, of the Woods Hole Research Center. Continue reading

Climate: Warmer temps to drive spread of drought

State officials hope to be well-prepared for the next inevitable drought in Colorado.

Drought is expected to expand the southwestern U.S. and other regions.

Evaporation seen as huge factor in climate calculations

Staff Report

FRISCO — Increasing global temperatures will drive drought expansion regardless of precipitation in some cases, as more moisture evaporates from soils.

An increase in evaporative drying means that even regions expected to get more rain, including important wheat, corn and rice belts in the western United States and southeastern China, will be at risk of drought. The study excludes Antarctica.

The new study models the effects of both changing rainfall and evaporation rates on future drought, estimating that 12 percent of land will be subject to drought by 2100 through rainfall changes alone; but the drying will spread to 30 percent of land if higher evaporation rates from the added energy and humidity in the atmosphere is considered.

Continue reading

Western streamflow forecasts a mixed bag

Severe drought continues in Southwest

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California, Arizona and New Mexico reporting very dry conditions.

By Summit VoiceFRISCO — Snowpack across the West is still somewhat of mixed bag in this no-Niño winter, but February storms did help bolster water supplies across the northern tier of states, according to the monthly update from USDA’s Natural Resources Conservation Service.

East of the Continental Divide as well as parts of Washington, northern Oregon, northern Idaho and western Montana are now forecast to have near-normal or above normal water supplies, according to the forecast from the NRCS National Water and Climate Center. Continue reading

Climate: How hot will it get in Colorado?

State releases draft climate change report, comments wanted

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How warm will it get in Colorado?

By Summit Voice

FRISCO — Climate experts say it’s about to get warmer —probably much warmer — in Colorado. A draft state climate report released this week for public comment shows that Colorado has warmed by 2.5 degrees Fahrenheit in the past 50 years. By the middle of this century, summer temperatures will be higher than in all but the hottest years, with another 2.5 to 5.5 degrees of warming expected. Continue reading

Climate: USGS says most California streams flowing at less than 10 percent of normal

Widespread western drought continues

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Much of the West has been very dry during the first four months of the 2014 water year.

By Summit Voice

As California experiences its worst drought in more than a century, it’s probably not surprising that some stream gages in the northern part of the state are showing all-time record low readings, with 2013 in the record books as the driest calendar year in the state’s 119-year recorded history.

Low streamflow affects water availability for agricultural, municipal, and industrial uses, water quality, water temperature, recreational opportunities, and the maintenance of fish populations.

Recent precipitation has resulted in some increases in streamflow, snowpack, and reservoir levels, but severe drought conditions remain. Without significant additional precipitation, prior conditions will quickly return leaving most streams in the state at less than 10 percent of normal for this time of year. Continue reading

California drought linked with global warming

‘What we are seeing now is fundamentally different from previous mega-droughts, which were driven largely by precipitation’

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Global warming is likely to exacerbate droughts worldwide.

By Summit Voice

FRISCO — While drought conditions have eased across parts of the U.S. in recent months, conditions have worsened in the far West, and particularly in California, where water shortages will have consequences spreading far beyond the state’s borders.

And the western drought has global warming fingerprints all over, according to four researchers who discussed the links between climate change and drought at a teleconference organized by Climate Nexus, a communications group focused on highlighting the wide-ranging impacts of climate change. Continue reading

Climate: U.S. temps cooler than average in 2013

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Cooler than average temperatures were widespread across the U.S. in December 2013.

California drought intensifies

By Summit Voice

FRISCO — December 2013 won’t go down in the record books for cold temperatures even though cooler-than-average readings prevailed across much of the country.

The average temperature across the lower 48 states was 2 degrees Fahrenheit below the 20th century average, making it the coldest December since 2009, according to the monthly summary released this week by NOAA’s National Climatic Data Center. Continue reading

New series of climate studies aim to pinpoint global warming impacts on key natural resources

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Glen Canyon Dam. Photo via U.S. Bureau of Reclamation.

Arizona researchers to focus on Colorado River flows as feds grant $7 million for 50-plus research projects

By Summit Voice

FRISCO — Arizona-based researchers will lead an effort to pinpoint how global warming will affect Colorado River flows in the coming decades, with an eye toward exploring links between Pacific Ocean climate patterns like El Niño/La Niña cycles and the occurrence of extreme wet or dry conditions.

The two-year study will result in a streamflow projection product that better accounts for physical mechanisms of weather and climate on a regional and local scale, that can be directly used by water resource providers.

The research project is one more than 50 studies funded by grants from the U.S. Department of Interior’s regional climate centers as part of President Obama’s Climate Action Plan to reduce carbon pollution, move the economy toward clean energy sources and begin to prepare communities for the impacts of climate change. Continue reading

Climate: Study suggests Pacific Northwest streamflow declines may be linked with waning winter winds

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Global warming may be changing westerly winds that drive weather patterns in the mid-latitudes of the northern hemisphere.

Crucial water supplies under the gun from a changing climate

By Summit Voice

FRISCO — Changes in runoff from winter snowpack have been widely documented across the West and most researchers attribute those changes to global warming. But along with the direct impact of warmer temperatures, there may also be a more subtle factor in play.

Recent Forest Service studies on high-elevation climate trends in the Pacific Northwest United States show that streamflow declines tie directly to decreases and changes in winter winds that bring precipitation across the region. The decrease in winter winds may be linked with natural climate variations and man-made climate change.

Other climate research on a larger scale suggests that circumpolar wind speeds may be declining as a result of melting Arctic sea ice —  the temperature gradient between the high- and mid-latitudes drives the wind, and that gradient is lessening. Continue reading

Climate: Is the Southwest ‘stuck’ in a drought pattern?

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NOAA’s winter outlook offers little relief for Arizona, New Mexico

By Bob Berwyn

FRISCO — Drought conditions may persist across the southwestern U.S. this winter and may redevelop across the Southeast, according to the seasonal outlook from NOAA’s Climate Prediction Center.

“Even though we don’t have La Niña, the atmosphere across the Pacific seems to be stuck in a La Niña mode … It’s been quite surprising to us, how persistent the pattern is,” said Mike Halpert, acting director of the Climate Prediction Center.

Parts of the Southwest, especially New Mexico, have been experiencing one of the driest periods on record, and Halpert said there is “decent agreement” in the CPC’s models on the climate signal that has resulted in the persistent trend. Continue reading

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