Will global warming desiccate the Southwest?

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

desert rain.

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

Study warns that some misguided climate change adaptation efforts could do more harm than good

Sea level is rising, and will continue to rise for centuries even if we cut greenhouse gas emissions.

Sea level is rising, and will continue to rise for centuries even if greenhouse gas emissions are stopped immediately, and low-lying areas like the Mississippi Delta are already feeling the effects. @bberwyn photo.

‘Functioning and intact forests, grasslands, wetlands and coral reefs represent our greatest protection against floods and storms’

Staff Report

Climate change adaptation is more than a slogan in many parts of the world, as communities work to protect themselves from the impacts of a warming world.

But a new study says planners must carefully think through their responses — some changes could leave people worse off in the future, according to scientists with CSIRO, the Wildlife Conservation Society and the University of Queensland.

Their findings, published in Nature Climate Change, discusses how certain adaptation strategies may have a negative impact on nature which in turn will impact people in the long-term. Many climate adaptation strategies such as sea wall construction and new agricultural practices do more harm than good, the researchers concluded. Continue reading

Greenland meltdown threatens key Atlantic Ocean current

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Sea ice swirls around Greenland in this NASA Earth Observatory photo.

‘If human activities are starting to impact this system, it is a worrying sign that the scale of human impacts on the climate system may be reaching a critical point’

Staff Report

Cold, fresh water from the Greenland Ice Sheet may disrupt a key ocean current in the North Atlantic, scientists said after updating estimates of the freshwater flux based on new satellite data. The study, published in the journal Nature Communications, warns that the changes could have as-yet uncertain implications for the global climate.

At issue is the Atlantic Meridional Overturning Circulation, which transports a large amount of heat into the North Atlantic where it is given up to the atmosphere and helps regulate the climate in Europe and North America. Continue reading

Weather and climate summit returns to Breckenridge

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Greenland’s ice is melting faster these days, posing a sea level threat to densely populated cities around the world. @bberwyn photo.

This year edition features sessions on Arctic ice melt and western wildfires

Staff Report

There’s a global climate deal on the books, but humankind will continue to grapple with the effects of greenhouse gas emissions for decades to come, including the almost inevitable meltdown of ice sheets and glaciers that will raise sea level steadily.

Scientists aren’t quite sure yet how high the waters will rise, but new measurement tools and more sophisticated models can help refine the projections. Those estimates are important, because two-thirds of the world’s cities have vulnerable populations of five million or more living in at-risk areas, less than 10 meters above sea level, according to Dr. Lora Koenig
a research scientist with the National Snow & Ice Data Center. Continue reading

Climate: Warm oceans gone haywire?

Powerful storms in Atlantic and Pacific

MODIS visible satellite image of Hurricane Pali taken at 5:30 pm EST January 11, 2016. At the time, Pali was intensifying into a Category 1 storm with 85 mph winds. Image credit: NASA.

MODIS visible satellite image of Hurricane Pali taken at 5:30 pm EST January 11, 2016. At the time, Pali was intensifying into a Category 1 storm with 85 mph winds. Image credit: NASA.

Staff Report

With large parts of the the world’s oceans consistently warming to record-warm levels the past few months, it’s probably not a surprise that there are some big storms spinning out at sea. Basic physics tells us that warmth is energy, and that’s now translating into some unusual developments, including what may be the earliest-ever hurricane in the central Pacific, according to this Twitter post from National Hurricane meteorologist Eric Blake.

Currently, yet another strong storm is developing in the Pacific. The National Weather Service says the system will also generate hurricane-force winds and waves up to 50 feet.

The Atlantic Ocean has also been hyperactive in recent weeks. A storm centered near Iceland developed hurricane-strength winds during the last days of 2015 and sent a surge of air so moist and so warm northward that temps briefly climbed above freezing at the North Pole during the heart of the coldest time of the year.

Another system in the central Atlantic has a 40 percent chance of subtropical or tropical formation in the next 48 hours, according to the National Weather Service.

 

 

Climate: Arctic sea ice near record-low extent

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Antarctic sea ice is back to a near average extent after running well above average for several years. @bberwyn photo.

End of year heat wave slowed expansion

Staff Report

Arctic sea ice extent in December ended up as the fourth-lowest on record, and is still hovering near a record low in mid-January, according to the latest monthly update from the National Snow and Ice Data Center.

Through 2015, the linear rate of decline for December sea ice extent is 3.4 percent per decade (about 17,000 miles) per year.

For the month, the sea ice extent averaged 4.74 million square miles, about 301,000 square miles below the 1981 to 2010 average for the month. The rate of sea ice growth slowed slightly throughout December and nearly stopped early in January, federal ice trackers said, suspecting that a period of unusually warm temperatures in the Arctic caused the slowdown. Continue reading

Wildfires burned across 10 million acres in 2015

Feds spend more than $2.6 billion on fire suppression

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Wildfire activity surged in 2015. Graph courtesy NIFC.

By Bob Berwyn

For the first time in the era of modern record-keeping, wildfires burned across more than 10 million acres in 2015, mainly due to a series of large fires in Alaska.

According to the U.S. Forest Service, there were more than 50 fires that exceeded 50,000 acres, and 20 fires exceeded more than 100,000 acres. The fires destroyed more than 4,500 homes and other structures and killed 13 wildland firefighters.

The big wildfire season came after two-year lull, when the total wildfire footprint stayed below 5 million acres. For the last years, the average now stands at about 6.6 million acres.

The uptick in fires is no surprise to experts, who have been warning that global warming will result in bigger burns. Alaska, for example, reported its second-warmest year on record in 2015. Since 2000, fire seasons have grown longer, and the frequency, size and severity of wildland fires has increased.

In 2013, scientists linked a spate of massive Siberian wildfires with a “stuck” weather pattern associated with global warming. Overall, scientists say, those links are becoming more clear. It’s also clear that forests will have a more difficult time rebounding from fires as temperatures warm. Continue reading

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