Environment

NASA study predicts devastating droughts during the last half of the century

NASA study predicts devastatin...
30-cm (11.8-in)-deep moisture projection based on NASA's high carbon emission scenario in the year 2095 (Image: NASA's Goddard Space Flight Center)
30-cm (11.8-in)-deep moisture projection based on NASA's high carbon emission scenario in the year 2095 (Image: NASA's Goddard Space Flight Center)
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30-cm (11.8-in)-deep moisture projection based on NASA's high carbon emission scenario in the year 2095 (Image: NASA's Goddard Space Flight Center)
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30-cm (11.8-in)-deep moisture projection based on NASA's high carbon emission scenario in the year 2095 (Image: NASA's Goddard Space Flight Center)
30-cm (11.8-in)-deep moisture projection based on NASA's moderate carbon emission scenario in the year 2095 (Image: NASA's Goddard Space Flight Center)
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30-cm (11.8-in)-deep moisture projection based on NASA's moderate carbon emission scenario in the year 2095 (Image: NASA's Goddard Space Flight Center)

A new NASA study is predicting the occurrence of severe "megadroughts" across the United States in the second half of this century, that are set to be more extreme and prolonged than any droughts that have taken place in the region for the past 1,000 years. According to the study, one of the key driving forces behind the devastating droughts will be the prolific creation of human-produced greenhouse gasses.

The study made use of several climate models including one spearheaded by NASA, and is the first of its kind to use historical data stretching back as far as 1,000 years. Most modern drought indicators only use data from around 100 years in the past, however NASA's most recent study was able to draw on environmental conditions prevailing in the distant past by making use of a well established tree-ring database.

Using this wealth of natural information, the team were able to pinpoint drought events by observing the spaces between rings in tree trunks, a process known as dendrochronology. Some trees grow significantly more during years with prevalent rainfall, producing wider spacing between the rings, and have stunted growth during periods of drought, creating closer rings. By observing ring patterns in the same species of tree during modern droughts, the study was able to produce accurate drought maps for the last 1,000 years. This allowed climate scientists to examine the big picture, taking into account drought cycles in a much longer context.

30-cm (11.8-in)-deep moisture projection based on NASA's moderate carbon emission scenario in the year 2095 (Image: NASA's Goddard Space Flight Center)
30-cm (11.8-in)-deep moisture projection based on NASA's moderate carbon emission scenario in the year 2095 (Image: NASA's Goddard Space Flight Center)

"Natural droughts like the 1930s Dust Bowl and the current drought in the Southwest have historically lasted maybe a decade or a little less," states Ben Cook, lead author of the study and climate scientist at NASA's Goddard Institute for Space Studies and the Lamont-Doherty Earth Observatory at Columbia University, New York. "What these results are saying is we're going to get a drought similar to those events, but it is probably going to last at least 30 to 35 years."

According to the study, the severity of future droughts will be determined by humanity's approach to carbon emissions in the coming years. Cook and his team state that with the current levels of greenhouse gasses in Earth's atmosphere, the possibility of a drought lasting around 30 years sits at around 12 percent. If carbon emissions level off around 2050, this figure rises to 60 percent. In the event of man-made carbon emissions continuing to rise at the current pace, there is a harrowing 80 percent chance of a megadrought engulfing the Southwest and Central Plains from 2050 to 2099.

Droughts of this magnitude and severity would place the agricultural capabilities of the US under greater stress at a time when there is already set to be significant food shortages on a global scale, in part thanks to the effects of global warming.

The video below courtesy of NASA highlights the key points made by the study.

Source: NASA

NASA | Megadroughts Projected for American West

25 comments
zevulon
droughts have zilch to do with rain. aquifers are being depeleted due to over irrigation and agricultural useage. there's more than enough water in canada to pipe down to the ogalala and california . the problem is overusage. nasa has their head up their asses.
justinmc
They still can't accurately predict the weather 2 days in the future, or the climate year to year, but they're going to be accurate 50 yrs in the future, sure that makes sense.
Matt Fletcher
NASA, now involved in the exploration and custom designed production of propaganda. I was thinking the same thing as zevulon and justinmc. Would like to add that greenhouse gases have very little long term effect on our atmosphere. If I'm wrong than lets see the equations prove prior weather correctly, but they can't. If they could do that then I'll believe the future predictions. Fortunately every weather simulation where CO2 emissions are considered important, calculate the weather ridiculously wrong.
Derek Howe
Our climate has too many variables at play to predict, Your attempt to predict it is futile.
Koplin
So let me get this tree rings are only controlled by how much moisture? Odd seeing how "old" growth trees in Alaska are toothpicks with rings so close you can't count them accurately some times. And the culprit isn't moisture, its the growing season. IE light. So unless they know what the entire atmosphere was like 1000 years ago and what the sun was doing then the accuracy of this "prediction" is low as well. I remember another gizmag/nasa story saying how there will be more forest fire and less rain etc from another such climate study. Likely from the same models. Dendrochronology can accurate date things, but predict future moisture, that's a stretch I am unaware of any evidence in the scientific community that makes that correlation. I have seen the moisture to tree ring size first hand in my archaeology studies, however that was studying the past, not the future. What happens when you warm up the ocean? Lets see if its like a pot of water then more evaporates. Where does that water come down? 2 seconds of google pulls this up: http://www.climatehotmap.org/global-warming-effects/rain-and-snow.html and http://www.scientificamerican.com/article/climate-change-is-altering-rainfall-patterns-worldwide/ and even NASA http://www.nasa.gov/topics/earth/features/wetter-wet.html "wet places get wetter, dry places get dryer" The result will be MORE movement, MORE water, sure its going to change WHERE the water is and that will effect people. We build pipes for all sorts of things, this will be no different. Hell the model even says the poles will get more moisture, so for all we know sea ice may grow, and if that's the case then the crazy idea of towing icebergs to cities for water might make sense. NASA needs to bring more to the table and GIZMAG needs to do some fact checking before just saying everyone will have no food, no water, and life is going to suck in 50 years. "80 percent chance of a megadrought engulfing the Southwest and Central Plains from 2050" - nasa/gizmag above however : http://www.c3headlines.com/2014/01/us-temps-nasa-1988-global-warming-predictions-noaa-failure-those-stubborn-facts.html 1988 predictions of CO2 & world temps. In summery NASA said that if the world climbing levels of CO2 that withen 30 years of 1988 global temperatures would climb by 2-5 degrees F. The realty was not much changed in that time.(temperature wise). and this one http://wattsupwiththat.com/2009/10/22/a-little-known-but-failed-20-year-old-climate-change-prediction-by-dr-james-hansen/ NASA's own James Hansen -Sea level rise. - prediction, extreme sea level rise. by this guy: http://en.wikipedia.org/wiki/James_Hansen reality http://wattsupwiththat.com/2009/10/22/a-little-known-but-failed-20-year-old-climate-change-prediction-by-dr-james-hansen/ not much to report other then the prediction was totally off the mark. So in summery, when NASA has a better track record with climate predictions then space shuttle launches then I might consider their input for for now I think the farmers almanac has better accuracy. For the record shuttle failures were 40% of total vehicles/ 1.5% total launches, almost 200 billion dollars and we still didn't return to the moon, but we got a flying pile of cans called the ISS.
christopher
LOL "If carbon emissions level off" - like, 7 billion (or by then 10 billion) people all decide to stop driving around, cooking, and heating. Dream on!! Our race is 100% incapable of making any noticeable change to the direction of our climate. You can't blame NASA - the government pays grants to people who hysterically shout their propaganda the loudest, and the USA needs to club the rest of the world into carbon trading to remain economically powerful. Nobody wants to believe how insignificant we are, or how little we can change anything - especially not when so many tree-hugers are happy to pay money, and vote, while their heads are below-sand! (oh, and shhh, it's the ocean currents that drive droughts, not air pollution, but don't tell NASA!)
Anne Ominous
Their models have not been able to project the climate accurately for even the last 2 months, much less 2 or 5 years, or 10. I would give the idea that they could predict the climate 40 years from now very nearly zero credibility.
The Hoff
I understand why we're talking about denial even though we should be talking about science. Wiki says between 2002 and 2010, conservative billionaires secretly donated nearly $120 million (£77 million) via two trusts (Donors Trust and Donors Capital Fund) to more than 100 organizations seeking to cast doubt on the science behind climate change. Now they just buy politicians, it's legal now. We don't need much oil. I run a sizable sound studio every day and drive my car all on solar panels on my roof. Don't be scared, we have the technology to live better, we just need the smarts. http://en.wikipedia.org/wiki/Climate_change_denial
MRing
Prediction of the future will always be 50/50. Regardless of whether NASA's climate prediction models are accurate or not, the fact remains that we need to be a sustainability based civilization. Water needs to be protected, C02 needs to be reduced and if there are new ways that we can be wiser with our resource consumption, they need to be actively implemented. Sustainability needs to be important. Every step that can be taken towards efficiency and sustainability needs to be taken and implemented, planet wide. Corporations need to fund these programs, not just the government, but the major producers. What is the point of sitting on 30 billion dollars if the very planet (or even your country) you live on is always on the brink of disaster. We are all stuck here. CEO's to blue collar. Everyone is stuck on the same planet in space together, and until we really get our act together and have a unified direction, that is a fact. We fail to really acknowledge that; and individually fail to act, and thus we fail to protect the very place we call home. Quickly look at this "megadrought" topic: whether it is an absolute certainty will always be unclear; but it is still a definite possibility that require precautions to be taken BEFORE we find out. This company here: www.hydrationlock.com HydroLock taking corrective steps in water consumption now. They have a water absorbing nano-technology polymer that reduces agriculture and horticulture water consumption by 70%. For everyone to use. If deployed across the globe into as many areas as possible, crops will become drought resistant, lawns will become efficient, and organic investments will live longer and healthier. These solutions need become more than just an idea, but daily practice for everyone. Then it just wont be a problem because we have taken the corrective measures ahead of time. With any luck, the world will agree, and their units will fly off the shelves.
The Hoff
The best and the brightest with Americas most incredible instruments used far more data then tree rings to do this study. The article just gave us the bare basics. In the 1940s there were still doctors in cigarette adds because of the companies misleading the public but those that continued to smoke still got cancer. Lets not let history repeat itself.