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Recurring droughts are clear and present dangers


Vikram MehtaDr. Vikram Mehta is the Founder, President and Executive Director of Center for Research on the Changing Earth System (CRCES), a non-profit, scientific research organization based in Maryland, U.S.A. He has graduate degrees in Science from India and Canada, and a masters and doctoral degrees in Meteorology from Florida State University in Tallahassee, Florida. He has worked on natural decadal climate variability (DCV) at the National Aeronautics and Space Administration (NASA) - Goddard Space Flight Center and the University of Maryland – College Park. For outstanding achievements in climate science, the Non-Resident Indian Welfare Society of India in 2015 bestowed on Vikram their highest award, the Hind Ratna (Jewel of India).

Is climate change the force behind the mass migrations into Europe? Is the rising radicalization and extremist behavior emerging in places like Pakistan and the Sahel region in sub-Saharan Africa linked to drought or climate change in any way?
These are legitimate questions. And, although we lack sufficient evidence now that is supported by robust data to make very firm claims, history offers some lessons, which suggest that we should prepare for the worst now, and hope that the future reality will prove us wrong.

Political upheavals have followed severe and recurrent droughts

A close look at the history of drought over a thousand-year time frame shows that the persistence of dry-wet cycles has consequences for water and food securities. This, in turn, can trigger insecurity that can evolve into full-blown armed conflicts at national and, even, international levels.[1] 

In the 1450s, for instance, severe droughts occurred in the Mississippi River valley and southern Great Plains of the United States. In the wake of these droughts, settlements of the Mississippian civilization were abandoned. 

In France, in the mid-1780s, a multiyear dryness worsened and turned into droughts. The famines that followed from these droughts became a catalyst of “the Great Fear of 1789” and the French Revolution. Almost in parallel, India suffered a severe famine, following the drought of 1789 to 1801. At least 11 million people died.

Similar disasters occurred in northeast Brazil in the 19th and 20th centuries. The droughts led to mass migrations to southern cities, which, in turn, caused socio-economic and political upheavals.  In the United States, an estimated 3.5 million people migrated from the Great Plains states which were affected by the “Dust Bowl” droughts of the 1930s.

More recently, in the 1970s and 1980s, the droughts in Niger and Ethiopia both ended in tragedy. In Ethiopia alone, over 1 million people died, and an inestimable number of people migrated from the drought-hit areas.

A prolonged drought in Syria in the first decade of the 21st Century may have acted as a catalyst of the breakout of civil war in the country in 2010. Over 250,000 people have died and 6 million people have migrated within Syria. Over 4 million people are still refugees in neighboring countries.

It is apparent that persistent dry and wet cycles in many parts of the world have shaped the civilizations of the last 1000 years. The effects of these cycles are felt even more strongly today. This is due to population growth, rising demands for water and food, and socio-economic and political strifes - even instabilities – triggered by these cycles, especially the dry phases of the cycles. Recent research shows a correlation between water scarcity and civil strife in Africa.[2]

Why do these cycles occur? What are their consequences for human societies? Can we predict them in advance? Can we develop policies to minimize or avoid their adverse impacts and benefit from their positive impacts? Impacts such as famine, death and social economic and political turmoil or even war, particularly if droughts last several years as they certainly will in the future, as they have done in the past?  Further, what should we do to cope with the combined effects of these dry-wet cycles and human-induced climate change?  

The future seems daunting; how long we delay action is what will matter

Dry and wet cycles are part of the natural climate cycles. The cycles come from the interactions of the ocean and the atmosphere in the Pacific, Atlantic, and Indian Ocean regions.

Everything we know about these cycles tells us to expect that they will worsen in this Century due to climate change. We also know that each of the dry and the wet phases of the cycles are consequential, and that our short-sightedness during the wet phase worsens the impacts of the dry phase.

However, the damage from these cycles is not fated. The heavy losses families, communities and countries may experience can be minimized by taking some essential actions.

First, in each country, scientists need to develop models and methodologies which simulate and predict the impacts the dry-wet cycles have on the land, water cycle, river flows (hydrology), crop yields and food production, and the socio-economic and political conditions. 

Second, each country should have in place a system to assess the information needs of farmers, water managers, government officials, and other related stakeholders. This information is needed to design and develop decision support systems to guide each of these actors in managing the land. (An example is provided in the case described below).

Third, in order for farmers to make use of the tools developed, including switching to new and better farming methods or options, they need financial safety nets to avoid jeopardizing their livelihoods.

The importance of tapping into the human factors when managing drought cannot be overstated. This is not just in relation to flagging an emerging drought. Drought conditions can exist even under normal conditions of precipitation due to human action. For example, drought conditions can exist where farmers switch to more water consuming (thirstier) crops or when soils are degraded. Governments and scientists can miss these signals because they rely on meteorological equipment to predict drought.

The bottom line is that substantial financial investments must be made in order to bring the current and future advances in climate and impact sciences to respond effectively to the growing global needs of food and water. The task is daunting. But, it needs to be and can be done, as my experience working in the Missouri River Basin (MRB) shows.

Lessons from Missouri River Basin

Missouri River Basin produces 46% of the wheat, 22% of the grain corn and 34% of the cattle produced in the United States.  However, only 12 million of the total 117 million acres of cropland is irrigated. The rest is left to the vagaries of climate variability. But bear in mind, irrigated cropland is also vulnerable when droughts occur several times within a decade because both surface and ground water are limited. 

More than 12 years ago, scientists from the Center for Research on the Changing Earth System (I am part of the team) together with researchers from other institutions in the United States have studied how natural climate cycles affect the Basin’s water and food systems.

Our research was motivated by a desire to minimize economic losses in the Basin for two reasons. First, climate cycles have big impacts on the Basin’s water and weather cycles. Second, we estimated that if the climate cycles can be predicted even one or two years in advance, the region’s agricultural economy could avoid losses of about US$80 million every year.

In our research, we assess the impacts that climate cycles have on water resources and agriculture. In order to develop the decision support systems, we assess the impacts and climate information required by stakeholders. Based on what we know about the cycles, we predict the potential impacts of the cycles on water and crops. Then, we develop adaptation options for managing the water and agriculture sectors. 

We succeeded in simulating and predicting crop yields reasonably well a year in advance – in some cases, several years in advance – by using two models together; a model for climate predictions and a hydrology-crop model. We have used these scenarios to develop adaptation options for a given climate outlook, for example, to plant corn or soybeans, alfalfa or wheat. 

The results are encouraging.

But, in order to convince stakeholders to implement the findings, we found that it is important to develop a record of successful predictions that we and the stakeholders can trust in making future predictions.

The research also shows that when a farmer starts to apply the predictions and adaptation options, financial safety nets to protect the livelihoods of the stakeholders, especially farmers, are needed.  These safety nets must be in place for many years until the farmers know how to use and apply the data and information about climate cycles and their impacts.

Trust farmers or prepare to fail

In the course of the research, I learned very important lessons and developed tremendous respect for the people who farm the land for various reasons.

First, farmers have an intuitiveness about dry-wet cycles and their impacts that comes from their own and their ancestors’ experiences.

Second, I have learned that weather and climate are just two of the many factors stakeholders consider when making their decisions. However, these factors may not always be the most important. Sometimes, weather and climate are not important at all in their decisions.

Third, farmers are definitely interested in the local information, but they know that the prices of their produce also depend on global market conditions. Therefore, they are equally keen to get predications about other major food-producing regions and countries that they will compete with, and about the condition of the markets in the countries that consume their produce.

Fourth, I learned that stakeholders are interested in using future outlooks of the climate cycles to make decisions. For example, they need information on whether rain or snow over the next 2, 3 or 5 years is likely to be above or below average.

Dry-wet cycles are a reality of our past, present, and future. These cycles and anthropogenic climate change will exacerbate each other’s impacts. The past shows that the impacts of the future cycles could have global political and social consequences if we delay action.

If we are to achieve the Sustainable Development Goals, we must work with farmers and other critical land users to avoid the catastrophic effects these dry-wet cycles, in addition to those of climate change.

A critical step in this regard is to integrate the kinds of scientific and programmatic models described above in the global policy frameworks that guide action on the issues of land, water and food, such as the Sendai Framework for Disaster Risk Reduction, the Sustainable Development Goals and the UN Convention to Combat Desertification.




Note: Vikram Mehta will present a talk at the UNCCD on 4 June 2018 that will address persistent dry-wet cycles and their worldwide impacts as well as possible actions.



[1] Mehta, V.M. (2017):  Natural Decadal Climate Variability:  Societal Impacts.  CRC Press, Boca Raton, U.S.A., 326 pages.

[2] Almer et al. 2017, Journal of Environmental Economics and Management, Water scarcity and rioting: Disaggregated evidence from Sub-Saharan Africa