Are We on the Verge of A Multi-Century Mega-Drought?

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People in contemporary societies often take core survival resources, such as water and food, for granted. The presumption that there will be sufficient rain (or other precipitation) to water crops and herds, as well as meet the needs of all of the people, is one that is rarely questioned or considered. Some may even mistakenly assume that that water is plentiful, abundant and perhaps even inexhaustible. However, when the rains lesson or stop altogether the “sudden” disappearance of such a fundamental requirement for life, business and the entire civilization can be a surprising and devastating disaster.Drought

Too frequently in human history, the occurrence of drought has been a catastrophic disaster for people in many different lands. Droughts are one of the major natural disasters that can disrupt the routine economic, lifestyle and social circumstances of a society. They can result in catastrophic occurrences such as famine and water exhaustion.

During the past few centuries in North America, we have endured a number of shorter term, geographically-specific droughts. For example, most of us know about the central U.S. “dust bowl” which lasted for a number of years during the 1930s (the Great Plains drought was not a mega-drought). In recent years, a number of area specific droughts have been (or are being) endured in North America. You can see current droughts using the U.S. Drought Monitor.

A prolonged drought is classified as a mega-drought. A mega-drought is a prolonged drought lasting 20 years or longer. Historically, mega-droughts target parts of the globe and have forced the mass migration of humans away from long-held homelands and killed off large percentages of populations. Mega-droughts are thought to have played a key role in the extinction of several ancient civilizations. Droughts are disruptive, costly and can create havoc with communities, businesses and the lives of many people. Mega-droughts can fundamentally damage or even end entire societies and civilizations.

Another Mega-Drought

A number of recent scientific studies have concluded that there is a significant risk for a mega-drought emerging in this century which may last from 35 or 40 years up to 80 years in duration. Dylan Baddour in his article Study Warns of Mega Drought to Come published in the online editions of the Houston Chronicle wrote that the researchers:

“[F]ound a substantial likelihood for a decades-long drought later in the 21st Century. ‘We found that global warming is very likely to lead to long-term drying in Western North America,’ said Benjamin Cook, a researcher with NASA Goddard Institute for Space Studies. ‘Not only drier than the 20th Century–it might be drier in the future than really extreme periods in the 12th and 13th centuries.’”

Writing in Scientific American Peter H. Gleick and Matthew Heberger (Devastating Drought Seems Inevitable in American West) observe that the coming north American mega-drought will be centered in the western half of the North America.

The research scientists (Benjamin I. Cook, Toby R. Ault, and Jason E. Smerdon) who authored the groundbreaking research study Unprecedented 21st Century Drought Risk in the American Southwest and Central Plains warn of this coming super disaster (Science Advances  12 Feb 2015: Vol. 1, no. 1, e1400082 DOI: 10.1126/sciadv.1400082) with the following observations:

Drought NASA“In the Southwest and Central Plains of Western North America, climate change is expected to increase drought severity in the coming decades. These regions nevertheless experienced extended Medieval-era droughts that were more persistent than any historical event, providing crucial targets in the paleoclimate record for benchmarking the severity of future drought risks. We use an empirical drought reconstruction and three soil moisture metrics from 17 state-of-the-art general circulation models to show that these models project significantly drier conditions in the latter half of the 21st century compared to the 20th century and earlier paleoclimatic intervals. This desiccation is consistent across most of the models and moisture balance variables, indicating a coherent and robust drying response to warming despite the diversity of models and metrics analyzed. Notably, future drought risk will likely exceed even the driest centuries of the Medieval Climate Anomaly (1100–1300 CE) in both moderate (RCP 4.5) and high (RCP 8.5) future emissions scenarios, leading to unprecedented drought conditions during the last millennium.”

AFP reporting on the study (Scientists warn of ‘mega-drought’ risk in western U.S.) continue further in interviews with the authors:

“Mega-drought is defined as any drought as bad as the worst already seen in the 20th century, but lasting much longer, for 35 years or more. The study is the first to predict that the coming intense dry spells could exceed the decades-long mega-droughts that occurred centuries ago and are blamed for the demise of certain civilizations in the late 13th century. ‘I was honestly surprised at just how dry the future is likely to be,’ said co-author Toby Ault, an assistant professor in the Department of Earth and Atmospheric Sciences at Cornell University. ‘I look at these future mega-droughts like a slow moving natural disaster. We have to put mega-droughts into the same category as other natural disasters that can be dealt with through risk management.’

The risks and dangers are worse today because of the larger population and greater dependence on water resources, scientists warned. Researchers applied 17 different climate models to analyze the future impact of rising temperatures on regions from Mexico to the United States and Canada. They also projected a continued rise in emissions of the greenhouse gases that contribute to global warming, and looked at a scenario in which actions were taken to cut back on greenhouse gases resulting in lower emissions. Both approaches raised concern for the future.

‘The results… are extremely unfavorable for the continuation of agricultural and water resource management as they are currently practiced in the Great Plains and southwestern United States,”’ said David Stahle, professor in the Department of Geosciences at the University of Arkansas who was not involved in the study.”

Mega-Droughts

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Western North America and specifically the Southwestern USA could be set for its worst drought in 1,000 years. The arid conditions in the southwest of the United States and the Great Plains have been caused by higher temperatures, while ground water supplies are shrinking. Studies by scientists using computer models show that the U.S. could be in for its worst droughts since the 12th and 13th centuries.

The 21st-century projections make the [previous] mega-droughts seem like quaint walks through the Garden of Eden,” said Jason Smerdon, who was a co-author of the paper, which was published in the journal Science Advances and is also a climate scientist at Columbia University’s Lamont-Doherty Earth Observatory. Ben Cook, from NASA’s Goddard Institute for Space Studies said:

These mega-droughts during the 1100s and 1200s persisted for 20, 30, 40, 50 years at a time, and they were droughts that no one in the history of the United States has ever experienced,” he said in a press release.

The droughts that people do know about like the 1930s ‘dustbowl’ or the 1950s drought, or even the ongoing drought in California, and the southwest today – these are all naturally occurring droughts that are expected to last only a few years or perhaps a decade. Imagine instead the current California drought going on for another 20 years,” Cook added.

BCP for Mega-Droughts

At first glance, the impact of a mega-drought may seem too large or scale and scope to even attempt to take steps to prepare to mitigate and survive. While some of the effects of a mega-drought will occur at the civilization level, there are many more dimensions of a drought or mega-drought for which there are prudent steps which can be taken to mitigate and sustain continuity of operations.

There are some resources which are worthwhile to review and consider how you might be able to implement appropriate measures suitable for your situation and context. The Ready.Gov website has business continuity planning resources to aid with planning and preparedness efforts for primary and secondary impacts from a drought.

There may be a wide range of supplier and infrastructure adjustments necessary to survive a prolonged multi-decade drought. Obviously issues such as water supplies, conservation, relocating workforce, transportation disruptions, food scarcity and/or food crisis, manufacturing disruptions, etc. have to be considered.

There are steps that individuals and families can take during a period of drought or mega-drought. There are also options available from the “survivalistcommunity to help survive a mega-drought (and global war over the remaining water).

Like all potential natural disasters, droughts and mega-droughts deserve a plan on the discussion agenda. It looks like it is going to be a warm, dusty and dry coming century.

Suggestions (links) for Further Reading:

Images: inhabitat.com; www.nasa.gov respectively

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