Posted on November 8, 2013 by Bob Berwyn
Shifts in precipitation patterns would have big consequences for agriculture, forests and municipal water supplies
Research suggests that deforestation will likely produce a weather cycle over the Amazon consisting of abnormally dry air in the sun-scorched northern Amazon around the equator weighted by wetter air in the cooler south (left). The Princeton-led researchers found that the Amazon pattern would be subject to meandering high-altitude winds known as Rossby waves that move east or west across the planet (center). The Rossby waves would move the dry end of the Amazon pattern directly over the western United States from December to February, while the pattern’s rainy portion would be over the Pacific Ocean south of Mexico (right). Image courtesy Princeton University.
By Summit Voice
FRISCO — Continued deforestation in the Amazon region could have significant impacts on the weather in North America, according to Princeton researchers, who used fine-grained climate models to simulate how precipitation patterns could shift in the future.
Their findings suggest that total deforestation of the Amazon may significantly reduce rain and snowfall in the western United States — specifically, 20 percent less rain for the coastal Northwest and a 50 percent reduction in the Sierra Nevada snowpack, a crucial source of water for cities and farms in California.
“The big point is that Amazon deforestation will not only affect the Amazon — it will not be contained. It will hit the atmosphere and the atmosphere will carry those responses,” said lead author David Medvigy, an assistant professor of geosciences at Princeton. Continue reading
Filed under: climate and weather, Drought, El Niño, Snow and weather | Tagged: Amazon Rainforest, climate, drought, El Nino, western U.S. | 1 Comment »
Posted on November 3, 2013 by Bob Berwyn
High flow experiment planned for early November to restore aquatic and riparian Colorado River ecosystems downstream of Glen Canyon Dam
By Summit Voice
FRISCO — Even with some bonus inflow in September, the past water year Oct 1, 2012 – Sept. 30, 2013) ended up as the fourth-driest on record for the Colorado River Basin as measured at Lake Powell — the key reservoir on the river that helps balance supply and demand between the upper and lower basins.
Overall water storage in the Colorado River Basin in the last 14 years has ranged from a high of 94 percent of capacity in 2000 to the present low of 50 percent at the start of the 2014 water year.
Filed under: climate and weather, Colorado, Colorado River, Drought, Environment, global warming, rivers, water | Tagged: climate change, Colorado River, drought, Lake Powell, water storage | 1 Comment »
Posted on October 22, 2013 by Bob Berwyn
New study says IPCC projections are too conservative
By Summit Voice
FRISCO — In a classic case of climate disruption, research shows that the dry season in southern Amazonia has lengthened by about one week per decade since 1979. Parts of the region may not be able to support rainforest vegetation much longer. A big forest die-back could trigger the release of large volumes of the greenhouse gas carbon dioxide into the atmosphere, a team of scientists warned this week.
The changes could disrupt plant and animal communities in one of the regions of highest biodiversity in the world, said University of Texas professor Rong Fu, who led the team of scientists. Continue reading
Filed under: climate and weather, Drought, Environment, global warming, greenhouse gases | Tagged: Amazon Rainforest, Climate disruption, global warming, Intergovernmental Panel on Climate Change, IPCC | Leave a comment »
Posted on October 13, 2013 by Bob Berwyn
Long-term climate shifts linked with historic spruce beetle episodes in Colorado
A Colorado spruce forest near Shrine Pass, Colorado.
Spruce beetles are spreading rapidly and killing trees in the southern Rockies.
By Summit Voice
FRISCO — The current spruce beetle outbreak in Colorado’s high country has the potential to grow larger in scope than the recent mountain pine beetle epidemic that killed mature lodgepole pines across millions of acres.
And the trigger of for the spruce beetles is drought that’s linked with long-term changes in sea-surface temperatures in the Northern Atlantic Ocean, a trend that is expected to continue for decades, according to a new study by scientists with the University of Colorado, Boulder.
The new study is important because it shows that drought is a better predictor of spruce beetle outbreaks in northern Colorado than temperature alone, said Sarah Hart, a CU-Boulder doctoral student in geography. Continue reading
Filed under: climate and weather, Colorado, Drought, Environment, Forest health, forests | Tagged: Atlantic Multidecadal Oscillation, climate, Colorado, Forest health, forests, southern rockies, spruce beetles | 2 Comments »
Posted on September 3, 2013 by Bob Berwyn
North American spring-season snow cover extent has declined steadily in recent decades, according to measurements from the Rutgers Global Snow Lab.
‘Shrinking in supply, growing in demand’
By Summit Voice
FRISCO — Since the 1980s, warmer spring temperatures in the Rocky Mountain region have been melting the snowpack earlier, with increasing temperatures tabbed as the main factor in the decline, according to the U.S. Geological Survey.
The agency carefully tracks streamflows and snowpack measurements, with decades of data now showing clear trends toward shorter winters, earlier spring runoff and an overall 20 percent shrinkage of the snowpack in the mountains of the western U.S.
The researchers say at least part of the changes are due to global warming caused by heat-trapping greenhouse gases, but that natural variability is also a factor. Regardless of the exact cause, the snowpack decline is already causing major headaches for water managers in the region facing dwindling supplies and increased demand.
The Colorado River Water Conservation District will focus on some of the emerging critical water questions during its annual water seminar (Sept. 13, 9 a.m. to 3:30 p.m.) in Grand Junction. USGS researcher Greg Pederson, who is the lead author on some of the key snowpack studies, will discuss how spring is killing the Rocky Mountain snowpack, especially at lower elevations, where the effects of warmer temperatures are more pronounced. Continue reading
Filed under: climate and weather, Colorado, Colorado River, Drought, global warming, rivers, water | Tagged: Rocky Mountain snowpack, The West, United States Bureau of Reclamation, United States Geological Survey | Leave a comment »
Posted on August 24, 2013 by Bob Berwyn
Fall and winter outlook still murky
Seasonal weather forecasters look out to sea surface temperatures in the equatorial Pacific to get an idea of what weather patterns may bring.
Without a stron El Niño or La Niña in the outlook, forecasters are not confident of projecting pronounced temperature or precipitation anomalies.
By Bob Berwyn
FRISCO — With no strong El Niño or La Niña on the horizon, forecasters are struggling even more than usual to develop seasonal outlooks for the western U.S. The periodic El Niño-La Niña cycle is a large-scale shift in the Pacific involving a complex interplay of winds, ocean currents and sea surface temperatures.
In the U.S. the warm El Niño phase is associated with wetter than average conditions in the Desert Southwest and California, and can result in below average precipitation in the Pacific Northwest.
La Niña, on the other hand, has been linked with Southwestern drought conditions and heavy precipitation in the Pacific Northwest. That persistent moist flow off the northwestern Pacific can also favor parts of Colorado with good winter snows, but the ENSO climate signal is more marginal in Colorado than in other areas. Continue reading
Filed under: climate and weather, Colorado, Drought, El Niño, La Niña, seasons, Snow and weather, Summit County snow and weather | Tagged: climate, Colorado winter snow, El Nino, ENSO, La Niña, seasonal forecast, weather | Leave a comment »
Posted on August 22, 2013 by Bob Berwyn
Conservation groups concerned about impacts
A map included in a draft version of a water plan is reason for alarm, according river activist Gary Wockner, with Save the Poudre, who says Front Range providers are targeting additional diversions from West Slope streams.
By Summit Voice
FRISCO — A Front Range alternative for a statewide water plan ordered by Colorado Gov. John Hickenlooper is drawing fire, as watchdog groups charge that the draft version puts too much emphasis upping diversions from Western Slope rivers.
“Just laying out this scheme of diversions and pipelines on a map enflames the political chaos around the Colorado River water supply crisis,” said river activist Gary Wockner director, of Save the Poudre.
According to Wockner, the draft plan being developed by the South Platte, Arkansas and Metro Roundtable could be an effort steer the state water plan toward more dams and diversions, at the expense of losing sight of the need for much more robust conservation measures. Continue reading
Filed under: agriculture, climate and weather, Drought, Environment, global warming | Tagged: Colorado River, rivers, water, water shortabne. | 5 Comments »
Posted on August 19, 2013 by Bob Berwyn
Colorado mule deer.
Environmental news from Colorado and the world
By Bob Berwyn
FRISCO — A busy week of writing news, including a cool story for MSN News about how the USGS and partner scientists at the Oregon Zoo are using smartphone technology to track polar bears.
And after several years of writing about the pollinator crisis, and expecially the decline in honey bees, it was great to see the story go mainstream with Time cover story. I also wrote a short related for MSN News about how systemic pesticides have been found in common garden store ornamental plants used by backyard gardeners.
For Summit Voice, my week started by pondering why on Earth an aquarium would even consider keeping marine mammals in captivity: Feds deny aquarium request for beluga whales.
One of the more interesting climate stories was about how the amplitude of the carbon cycle has intensified as plants cope with more CO2 in the atmosphere: Global warming: Earth is breathing more deeply these days.
We also posted our summary of the monthly NOAA U.S. climate analysis, with links back to the full report: Climate: Average U.S. temp above average for July.
This story on bees in Scotland was the big social media hit of the week, with scores of retweets on Twitter and Facebook likes, as the buzz about bees makes waves throughout the web: UK beekeepers report widespread loss of colonies.
Plenty more cautionary climate tales (that’s why they call us alarmists):
And some other stuff:
Summit Voice environmental photography:
Summit Voice photography:
Filed under: Arctic, climate and weather, Colorado, Drought, Environment, global warming, Summit County Colorado, Summit County news | Tagged: Antarctica, extreme weather, global warming, MSN, Oregon Zoo, West Antarctica | Leave a comment »
Posted on August 17, 2013 by Bob Berwyn
Climate experts outline weather extremes across the U.S.
By Bob Berwyn
After years of persistent drought across big swaths of contiguous 48 states, the weather picture changed dramatically in 2012. Instead of dealing with parched ground, farmers in the Southeast weren’t able to harvest crops this summer because of standing water in the fields.
Mold and fungal diseases were reported across the region, particularly on crops such as corn, tomatoes and peanuts. The excess moisture has degraded the quality and flavor of many crops, including watermelons, tobacco, and peaches. Flooded soil has hampered the growth of cotton and corn, with damage from excess moisture expected to cost billions, The National Climatic Data Center reported this week in its July update. Continue reading
Filed under: climate and weather, Drought, flooding, seasons | Tagged: climate, drought, extreme weather, flooding, National Climatic Data Center, National Oceanic and Atmospheric Administration | 1 Comment »
Posted on August 16, 2013 by Bob Berwyn
A NASA satellite image of the Colorado River and Lake Powell in Utah and Arizona.
Federal water agency says it will cut deliveries from Lake Powell next year
By Bob Berwyn
FRISCO — Colorado River water supplies are already stretched dangerously thin, and the faucet is about to get turned down, as federal water managers said they will probably have to curtail downstream deliveries from Lake Powell in 2014.
July inflow into Lake Powell was just 13 percent of average, following a spring runoff season during whic the river delivered only about a third of the average amount of water. Continue reading
Filed under: climate and weather, Drought, Environment, rivers, Uncategorized, water | Tagged: Colorado River, Colorado River compact, Glen Canyon Dam, Lake Mead, Lake Powell, United States Bureau of Reclamation | 2 Comments »