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Sept. 19, 2020

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WSUV researcher studies climate, drought

She connects dots between climatic events and famine amid rising global temperatures

By , Columbian staff writer
Published:

The world’s most catastrophic drought and subsequently deadly famine of the last 800 years was less than a century and a half ago.

Now, a Washington State University Vancouver researcher has uncovered the climatic events that gave rise to the Great Drought and warns that rising global temperatures could make a similar drought even worse — should it happen in the modern era.

Deepti Singh is an assistant professor in WSU’s School of the Environment. A few years ago, as a post-doctoral student at Lamont-Doherty Earth Observatory at Columbia University, she read “Late Victorian Holocausts: El Niño Famines and the Making of the Third World.”

The book describes how the Great Drought of 1876-78 and the subsequent global famine that killed a minimum of 50 million people — about 3 percent of the then-global population — and  devastated societies across three continents.

It was arguably the worst environmental catastrophe humanity has ever experienced and among the most deadly events in modern human history, alongside the world wars and the influenza pandemic of 1918-19. The drought led to widespread crop failures, coupled with the resource demands by colonial powers over India and parts of Africa, creating the global famine.

“The book talks about famine and social-political factors — mostly the causes and consequences of the famine; we got interested in the role of climate conditions in causing this famine,” Singh said.

Singh and other researchers wanted to understand the severity of the drought and the underlying mechanisms that made it so enduring.

Understanding that information will help scientists eventually predict the when and how of severe future droughts of such widespread and prolonged endurance, she said. What’s more, they’ll be able to understand how those droughts impact societies and their effects on the global food supply.

They began research that led to the Oct. 4 publication of a paper in the Journal of Climate, completing work that Singh had continued working on after arriving at WSU Vancouver in June. The work by Singh and her co-authors was supported by a fellowship from Columbia University’s Lamont‑Doherty Earth Observatory.

Singh looked back in time by using tree-ring data, rainfall records dating back sometimes hundreds of years and climate reconstruction to reveal the conditions leading up to the Great Drought.

What they found was there were actually multiple droughts in multiple seasons happening concurrently. Also, the drought experienced by India, Southeast Asia and southern China were the most intense and second-most expansive in the last 800 years.

Extreme weather

The drought likely stemmed from the strongest El Niño ever recorded, which came on the heels of the longest La Niña, or cool period in the tropical Pacific. But El Niño, even an extremely powerful one, cannot affect the entire globe. However, in 1876 through 1878, that extremely powerful El Niño occurred just as two other extreme climatic events took place, collectively creating the conditions for global starvation.

One was the Indian Ocean dipole, which is extremely warm water conditions in the western part of the ocean and cool conditions in the east. The third was an extremely powerful Atlantic Multidecadal Oscillation, an ongoing series of long-lasting changes in sea surface temperatures in the North Atlantic Ocean.

The same three conditions actually have happened again in the same way as the Great Drought, in 1997 through 1998, but not to the same level of severity.

While the much of the rest of the world —Australia, Brazil, North Africa, Southeast Asia — were in the grips of a dire drought in the late 1870s, the Pacific Northwest was immersed in an extremely wet period.

“The reason, given how wet it was here is an indication of the strength of the El Niño, it’s one of the areas directly affected by them,” she said.

What Singh and others now know is this event was caused entirely by natural variability, so it’s entirely possible it’ll happen again. What’s more, as climate change heats the planet, it’s possible a future great drought could be even stronger than the last one.  So they want to understand what effect it would have on the global food network. If history is any teacher, it could be severe.

“The important aspect is with single-year droughts, societies can cope, but having multiyear droughts, consecutive droughts can have a major impact and we need to understand that better — and the likelihood of that happening again,” she said.

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