Posted on 07/25/2019 7:12:05 AM PDT by null and void
By less than an hour agoweather.com
(Getty Image)
A dry landscape stands on Navajo Nation lands on June 7, 2019, in the town of Gallup, New Mexico. Rising temperatures associated with global warming have worsened drought conditions on their lands over recent decades leading to a worsening of water access.
At a Glance
• The U.S. Southwest experienced a dozen megadroughts from the years 800 to 1600.Scientists say they have pinpointed the cause of medieval megadroughts that stretched for decades at a time, and they warn climate change could soon cause them to return to the American Southwest.
• These droughts lasted for decades at a time.
• Researchers say they have discovered the cause of those droughts.
• Climate change could cause another megadrought soon, they say.
From the 9th through the 16th centuries, the Southwest experienced about a dozen megadroughts. These extreme droughts were caused by a combination of three factors, according to a new study by researchers at Columbia University's Lamont-Doherty Earth Observatory.
Two of the factors were warming sea surface temperatures in the Atlantic Ocean and high radiative forcing, which occurs when the atmosphere traps more energy from the sun than it radiates back into space, according to the study published this week in Science Advances.
The third, and most important factor, was severe and frequent La Niña events, periods when tropical Pacific Ocean temperatures are cooler and storms are pushed toward the Northwest.
“Both a warm Atlantic and a cold Pacific change where storms go,” Nathan Steiger, the study's lead author, told Vice. “They both result in fewer storms going to the Southwest.”
(Ghetto Image)
Parched land stands along a dried river on Navajo Nation lands on June 7, 2019, near the town of Thoreau, New Mexico. Rising temperatures associated with global warming have worsened drought conditions on their lands over recent decades leading to a worsening of water access.
On top of having less rainfall because of fewer storms, the radiative forcing caused any moisture that was there to evaporate more quickly.
Beginning in 1600, volcanic eruptions that spewed particles into the atmosphere blocked some of the sun's energy and decreased the effect of radiative forcing, thereby greatly reducing the number of megadroughts.
However, the increased burning of fossil fuels that started with the Industrial Age pumped more carbon dioxide into the atmosphere, which is again trapping the sun's energy.
This makes the Southwest, parts of which have seen ongoing drought for years now, more vulnerable to megadroughts, according to the Earth Institute's State of the Planet blog.
“Because you increase the baseline aridity, in the future when you have a big La Niña, or several of them in a row, it could lead to megadroughts in the American West,” Steiger said.
Forecasting the effect of climate change on La Niña events remains tricky, the study says. The bigger worry may be "the possibility that radiative forcing could gradually come to dominate the hydroclimate of the Southwest, with the recurrence of megadroughts becoming almost assured."
Climate Change scientists make Frau Mueller look intelligent.
The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.
OTOH, so does half of congress...
So, there was “climate change” from 800 to 1600 A.D.
It was air conditioning and all the SUVs driven back then.
Currently no part of New Mexico is under severe drought conditions, and less than 9% is in moderate drought conditions.
That’s a lot better than most of the previous decade.
The Mojave Desert is going to be dry due to global warming.
Is that it?
I’ll bet anyone $100 that unprecedented rain and floods occur there within the next 12 months.
O....M....G!...
A lot of the Navajo Nation sits on a mile high freaking DESERT you weather idiots. I’ve lived in 4-corners on the reservation border 50 years at 5,500 feet and yes it gets hot in the summer. Every freaking year like clockwork. Last year called a drought with no washing the car water restrictions, this year southern rockies 30 miles North at 400% of snowpack has the rivers over their banks in places. Wash your car all you want. Next year will bring one or the other again.
Jeez...you mean there were severe mega droughts before we all drove suvs? Who would have thought? And this rising temperatures bs...if a half degree increase causes so much gloom doom and disaster we may as well pack it in anyway...the earth/climate has been warming for 12000 years..duh...
These Idiots should have their Scientist Permit revoked
Exactly!
And Mount Everest’s peak will be cold.
Also, Hawaii will have lava flows...
I can’t wait for another ice age.
Some times the desert blooms, most of the time it does not.
It has rained just about every day here in SC Texas this summer. Very unusual.
The native Americans disappeared around 1000 years ago in this area because of DROUGHT. In more recent history the 1950s were terribly dry and that came after the dust bowl days of the 30s.
It is called nature, we don’t cause it and we can’t control it.
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