Rising atmospheric carbon could heighten ‘megadrought’ risk, study finds

If you remember (or even if you don’t) in “Climatological shift, cliff and other choice thoughts,” I insisted: “Whether one identifies oneself as a climate-change denier or climate-change believer there is no denying the climatological ‘cliff’ and ‘shift’ ideas.”

Elaborating farther, I explained, “There is no question … there exists in this existence the notion of ‘climatological cliff.’ It’s indisputable. And there is incontrovertible evidence that such was once overshot. Think ‘ice age.’ Not as drastic but still profound is the notion of ‘climatological shift.’ What this implies is meteorological change as in a marked change in climatic conditions or patterns.”

So, when I found the National Aeronautics and Space Administration (NASA) Feb. 12, 2015 “NASA Study Finds Carbon Emissions Could Dramatically Increase Risk of U.S. Megadroughts” news release, right away my curiosity was piqued.

The_Earth_seen_from_Apollo_17[1]Throughout history there have been droughts. According to NASA, in North America between 1100 and 1300, so-called “medieval-period” droughts occurred. Separating those from what the U.S. Southwest is experiencing today is that in the case of the former, some dry periods lasted as long as half a century.

Ben Cook, a climate scientist at the space agency’s Goddard Institute for Space Studies in addition to the Lamont-Doherty Earth Observatory at New York’s Columbia University, observed: “‘Natural droughts like the 1930s Dust Bowl and the current drought in the Southwest have historically lasted maybe a decade or a little less,’” although in the decades to come, drought durations could dramatically lengthen.

Cook, who headed a team in a recent NASA study, expressed that between 2050 and 2099, the likelihood of a megadrought lasting decades in both the Central Plains and Southwest regions, is 80 percent if, throughout the 21st century, the increase in greenhouse gas (GHG) emissions along current trajectories continue, that is, as I understand things. On the other hand, if, by 2050, the increase in GHGs is stemmed, Cook and study colleagues project the likelihood of megadrought to fall to north of 60 percent. Should either projection come to pass, what this could mean for the Central Plains and Southwest regions is nothing short of a significant reduction in the amount of precipitation and along with this heightened soil-moisture evaporation. Comparatively, at present, according to the study team leader, the likelihood of a drought lasting three decades or longer is 12 percent.

“The scientists analyzed a drought severity index and two soil moisture data sets from 17 climate models that were run for both emissions scenarios. The high emissions scenario projects the equivalent of an atmospheric carbon dioxide concentration of 1,370 parts per million (ppm) by 2100, while the moderate emissions scenario projects the equivalent of 650 ppm by 2100,” NASA in the release continued.

Furthermore, side-by-side comparisons of megadroughts of the past with 21st century computer-model projections reveal “both the moderate and business-as-usual emissions scenarios are drier, and the risk of droughts lasting 30 years or longer increases significantly,” adds NASA in the release.

Carbon dioxide concentration in the atmosphere, meanwhile, is presently 400 ppm.

For more on the NASA study, go here.

Image above: NASA

This post was last revised on May 9, 2020 @ 7:35 a.m. Pacific Daylight Time.

– Alan Kandel

5 thoughts on “Rising atmospheric carbon could heighten ‘megadrought’ risk, study finds”

  1. If you remaining climate blame conservative hating “believers” think 34 MORE years without climate action to SAVE YOUR PLANET is going to go away, then think again. Maybe it’s time science started breaking the rules and and started saying it’s “proven”that the end is near? The world needs to “believe” a CO2 death threat. It’s up to you now.

    • All I ask is you show me the mechanism for this? I will follow OK, I’m familiar with refraction, phase shift, and have an understanding of physics.

      If you are unable to its probably because you don’t understand it yourself but have swallowed others opinions.

  2. Our climatic variations tie in with Sun spot cycle activity, exactly. Unless you able to show a simple and straightforward mechanism, illustrating how our atmosphere is able to act as a one way valve allowing heat for the Sun in not out again I put the Carbon Theory in the trash can where it belongs. CO2 is released from water by heating, it may not now considered a heating cause, because this reverses a cause with effect, junk science like perpetual motion.

    Every thing must be explained, and exactly how it works. When anyone is unable to do this they don’t understand, it remains only an opinion. Ask those who claim to know, to explain simply please?

    As an explanation instance, why does a ball roll down hill? Explain why and how does this mechanism work? On a flat surface the Ball’s CG is over the center of its contact area. Raise one corner of the surface it rests on, and the CG will move outside of this area, projecting a vertical line to the surface we can scale and triangulate the forces from the weight, angle of change and the distance from the contact point. This shows and quantifies the potential energy moving the ball sideways, and its direction of travel. We can also calculate the balls velocities and kinetic energies all within the laws of dynamics, Carbon theory supporters must do the same, which so far they have failed to do.

  3. It’s up to me?

    OK the case is not supported outside of computer models. CO2 is released from water its primary store by heating, please explain exactly how a cause and its effect are reversed so it becomes a driving force of warming.

    Do you have a physics mechanism for your claimed effect or do you not know? I will not be persuaded that CO2 is any problem unless folk explain why they think it is?

  4. A read of the “100k-year cycles, temperature swings and GHG rises: What does it all mean?” post (link here: https://alankandel.scienceblog.com/2019/01/10/100k-year-cycles-temperature-swings-and-ghg-rises-what-does-it-all-mean/) might be in order here.

    As might a visit to the “BensonFamilyHomePage” with regard to the “Ice Age and Global Warming” content (link here: https://sites.google.com/site/bensonfamilyhomepage/Home/ice-age-and-global-warming). also.

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