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."
That does not make them correct on climate or Mueller.
We must act now before it is too late again.
These scientists learnt all about klimate change in gummint skools. They blinded me with pseudoscience.
“So, there was climate change from 800 to 1600 A.D.”
Our ancestors caused that by riding in their Ox carts instead of solar powered carts.
Just think of all those Ox farts over 800 years.
See. Global Climate Change.
Coming... back...
Which implies this happened long before industrialization? Huh...
A few years ago, 2013 and 2015, while driving through my old home of NE New Mexico, I was shocked to see it green for the first time in my 72 years!
In the past, it has always been a hard, hot dry land.
I think that California is in a similar situation.
According to his bio, "came to Columbia University as a NOAA Climate and Global Change Postdoctoral Fellow"...IOW, he's supposed to find things changing or lose his subsidy.
His comments are full of caveats..."could", "might"...uh huh.
The current situation in the West is that it's recovered significantly from recent droughts. Will there be more? Of course. Will they be anthropogenic? Maybe a teeny bit in local areas.
But Nathan is trying to fluff all that up, because he's an ideological kid spouting top level crap. And he needs the stipend..
Fear mongering sells.
Really? Last night on the local news they were almost giddy proclaiming Arizona drought free for the first time in who knows how long.
I guess they were lying.
I wonder if these “scientists” can explain why these very same conditions existed before AGW?
"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..."
IOW, the solar constant is variable, the sun was just a hair hotter 800 to 1600 A.D.
That warmed the Atlantic, and pumped a wee bit more energy into the atmosphere than could passively radiate out into space.
“Let me see if I’ve got this right.
The Mojave Desert is going to be dry due to global warming.
Is that it?”
Correct. The Sonoran Desert as well.
End of July and it rained a couple of days ago here on the beach in San Diego.
If they were so smart they would have invented a Weather Machine by now. I think I saw a Hollywood Movie where they did just that. Crank up the CGI Machines!
Since we all know the Climate does change over time, and did so long before the Industrial Age of Man, there is nothing we can do about it.
You adapt or your die. The Wooly Mammoths didn’t get the Memo before the last Ice Age hit.
So these mega droughts that occurred between 800 and 1600 were caused by man made globul warming of the 20th and 21st centuries?
Yes... it correlates with a rise in Sport Utility Wagons pulled by farting Oxen.
yes... SUW's and flatulence were the culprits.
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