Tag: drought

Study eyes ‘flash drought’ forecasts

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

Soil moisture, snowpack data help inform new forecast modeling

Staff Report

Some droughts creep up on you, while others seem to come out of nowhere, like in 2012 when spring came early and a hot, dry summer parched fields and forests and led to a busy wildfire season, including the destructive Waldo Canyon blaze near Colorado Springs.

Seasonal forecasts issued in May 2012 did not foresee a drought forming in the country’s midsection. But by the end of August,  the drought had spread across the Midwest, parching Oklahoma, Kansas, Nebraska, and Missouri. Now, after analyzing conditions leading up to the drough, researchers at the National Center for Atmospheric Research, say similar droughts in the future could be predicted by paying close attention to key indicators like snowmelt and soil moisture.  Continue reading “Study eyes ‘flash drought’ forecasts”

Study says global warming ups odds of Southwest megadrought

Heat-trapping greenhouse gases may dessicate Colorado River Basin

The paradox of water in the desert, illustrated by a NASA satellite image of the Colorado River.
Megadroughts ahead? Satellite photo of the Colorado River Basin via NASA.

Staff Report

It’s very likely the southwestern U.S. will be hit by droughts unlike any seen since the region was settled by Europeans. Global warming has driven the odds of a 10-year drought to at least 50 percent, and the chances of a 35-year megadrought range from 20 to 50 percent during the next century, according to a new study led by researchers with Cornell, the University of Arizona and the U.S. Geological Survey.

Global warming is “weighting the dice” for megadroughts, said lead study author Toby Ault, explaining that the buildup of greenhouse gases is shifting the climate dramatically. The study is set to be published in an upcoming issue of the  American Meteorological Society’s Journal of Climate. Continue reading “Study says global warming ups odds of Southwest megadrought”

California tree deaths part of global wave of forest mortality

Climate change is wiping out forests on a staggering scale

forests dying because of global warming
Red and dead lodgepole pines in Colorado. @bberwyn photo.
A beetle-killed lodgepole pine branch in Summit County, Colorado.
A beetle-killed lodgepole pine branch in Summit County, Colorado. @bberwyn photo.

Staff Report

California’s multiyear drought killed even more trees than previously thought, the U.S. Forest Service announced this week. Aerial and ground surveys show that 26 million trees across six counties in Southern California died, in addition to the 40 million trees that died statewide from 2010 to October 2015. Four years of drought, high temperatures and an outbreak of tree-killing bark beetles all contributed the historic levels of tree die-off, the agency said.

The tree mortality in California is the latest crest in a wave of forest die-offs in the past few decades linked with global warming. In the Southwest, an outbreak of ips beetles after the 2002 drought killed 80 percent of the piñon pine forests in the Four Corners region.

Around the same time, pine beetles started spreading across northern Colorado, parts of Wyoming and North Dakota, ultimately killing millions of acres of forest. And just as the pine beetle infestation waned, a spruce beetle outbreak in southern Colorado started to spread. Since 1996, spruce beetles have killed trees across about 1.5 million acres of forest.

Huge swaths of Colorado aspen forests also died in the early 2000s in a mortality event linked with extreme heat, and forest researchers say hardwood forests in the northern U.S. are also at risk from global warming. Continue reading “California tree deaths part of global wave of forest mortality”

Emerging La Niña likely to end streak of record-warm years

Pacific Ocean ENSO cycle a key player in global climate

La Niña
Cooler water welling up along the coast of South America and moving west suggests the start of La Niña in the Pacific Ocean.

By Bob Berwyn

The shift from a powerful El Niño to the cooler La Niña phase of Pacific Ocean temperatures will temporarily end the planet’s recent record streak of record-warm years, according to climate scientists who see the cyclical ocean changes as a key factor in the long-term global climate change equation.

Nearly all record-warm global years since 1950 (when accurate records start) have come during during El Niños, when the Pacific Ocean releases heat to the atmosphere and  intensifies global warming caused by heat-trapping greenhouse gas pollution. The 2015-16 El Niño was one of the strongest on record, but it has now ended, according to the National Oceanic and Atmospheric Administration, which says sea surface temperatures in the central and equatorial Pacific have cooled to average in the past few weeks. Continue reading “Emerging La Niña likely to end streak of record-warm years”

Environment: Can prescribed fires make forests more resilient?

New study focuses on drought-stricken California forests

Beetle-killed forests now dominate the landscape in Summit County. Prescribed fires are needed to help regenerate forests and clear dangerous fuels, according to White River NF supervisor Scott Fitzwilliams.
Prescribed fires could help make forests more tolerant to drought and more resilient in a warmer climate. @bberwyn photo.

Staff Report

A rising tide of insect infestations, tree mortality and wildfires — all caused by global warming — has resulted in political pressure for more logging in U.S. Forests, but there’s plenty of research showing that cutting down trees doesn’t do much good and can even increase the fire danger.

Exploring alternative options for strengthening forest resiliency, researchers with the U.S. Geological Survey and the National Park Service recently found that thinning forests with prescribed fires can reduce drought. Continue reading “Environment: Can prescribed fires make forests more resilient?”

So how, exactly, does global warming kill forests?

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

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?”

Climate: Snowpack dwindles across southern Colorado

‘Every El Niño is different’

western precipitation map 2016
Precipitation across the West has been patchy for the water year to-date.

Staff Report

March snowfall across the Colorado mountains helped maintain the statewide snowpack near average for the water year to-date, but the strong El Niño hasn’t played out as expected.

Instead of boosting moisture in the southwestern corner of Colorado, this year’s edition of the Pacific Ocean warm-water cycle sent the storm track surging into the Pacific Northwest and then down across Colorado’s northern mountains. Northeastern Colorado has been the wettest of all, with a wide section of the plains seeing up to double the average annual rainfall so far.

That’s bad news for the Southwest, where moisture has been sparse for the past several years. Western New Mexico, most of Arizona and the southern California deserts and coast have been especially dry since the start of the rainy season. Regionally, snowpack in the Colorado River Basin above Lake Powell was 94 percent of average as of March 17, and the Federal Bureau of Reclamation is projecting that the inflow to Lake Powell will be just 80 percent of average for the April to July period. Continue reading “Climate: Snowpack dwindles across southern Colorado”