Hotter, Drier, Meaner: Climate Trends Point to a Planet Increasingly Hostile to Agriculture

A host of data – from sediment cores to ongoing drought in East Africa to computer models – point to one conclusion:

Our increasingly hotter, drier planet is going to be a tough place to farm.

Africa man

Douglas Fischer, in a Daily Climate repost

SAN FRANCISCO – To get a glimpse of the future, look to East Africa today.

The Horn of Africa is in the midst of its worst drought in 60 years: Crop failures have left up to 10 million at risk of famine; social order has broken down in Somalia, with thousands of refugees streaming into Kenya; British Aid alone is feeding 2.4 million people across the region.

That’s a taste of what’s to come, say scientists mapping the impact of a warming planet on agriculture and civilization.

East Africa map“We think we’re going to have continued dryness, at least for the next 10 or 15 years, over East Africa,” said Chris Funk, a geographer at the U.S. Geological Survey and founding member of the Climate Hazard Group at the University of California, Santa Barbara.

Funk and other experts at the American Geophysical Union meeting in San Francisco cautioned that East Africa is just one example. Many recent events – discoveries from sediment cores of New York marshes, drought in Australia and the western United States, data from increasingly sophisticated computer models – lead to a conclusion that the weather driving many of the globe’s great breadbaskets will become hotter, drier and more unpredictable.

Even the northeastern United States – a region normally omitted from any serious talk about domestic drought – is at risk, said Dorothy Peteet, a senior research scientist with NASA’s Goddard Institute for Space Studies.

A series of sediment cores drilled from New York marshes confirm that mega droughts can grip the region: One spanned from 850 to 1350 A.D., Peteet said. And shorter, more intense droughts have driven sea water far up the Hudson River, past towns such as Poughkeepsie that depend on the river for drinking supplies.

“We’re just beginning to map the extent, but we know it was pervasive,” she said. “There are hints of drought all the way up to Maine.”

Of course, climate change can’t be blamed for all the food shortages and social unrest, several researchers cautioned. Landscape changes such as deforestation can trigger droughts, while policy choices exacerbate impacts.

Africa SheepSome hard-hit African countries have the highest population growth rates on the planet, and gains in agricultural productivity simply have not kept up with those extra mouths. Per capita cereal production, for instance, peaked worldwide in the mid-1980s, Funk said, and is decreasing everywhere. But no place on the globe is decreasing faster than East Africa.

Simple policy decisions can blunt a crisis. Malawi, in southeastern Africa, gave farmers bags of seed and fertilizer and saw food prices fall and the percentage of its population classified as undernourished drop by almost half over a decade, Funk added. Kenya, in contrast, saw its policies stagnate; prices and malnourishment rates both rose.

Central America map

Meanwhile, researchers probing the climate in pre–Colombian Central America figure that widespread deforestation had a hand in the droughts thought to have toppled the Mayan, Toltec and Aztec civilizations.

More than 1,000 years ago, “significant deforestation” throughout Central America suppressed rainfall upwards of 20 percent and warmed the region 0.5ºC, said Benjamin Cook, a NASA climatologist.

The forest – and local moisture – rebounded with the population crash that followed European contact, he added. But today the region is even more denuded than during its pre-Colombian peak.

But with the frequency of droughts expected to triple in the next 100 years, researchers fear the resulting variability and stress to agriculture and civilization could prove destabilizing for many regions.

“We should take it seriously,” Peteet said.

Photos (from the top): Young man in a field in eastern Africa courtesy Kimberly Flowers/USAID. Map of famine projections in East Africa courtesy Famine Early Warning Systems Network. Dead sheep at a livestock watering well in northeast Kenya during the 2006 drought courtesy World Food Programme. Map showing deforestation estimates for Central America during the pre-Colombian era courtesy NASA.

— Douglas Fischer, in a Daily Climate repost

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4 Responses to Hotter, Drier, Meaner: Climate Trends Point to a Planet Increasingly Hostile to Agriculture

  1. Gail Zawacki says:

    Scientific research and reports from government agencies such as NASA, the US Dept. of Ag., and EPA also tell us that in addition to increasingly vicious droughts and floods from climate change, crop yield and quality is reduced from exposure to air pollution. Since the background level of tropospheric ozone is persistant and inexorably rising, this is a global problem for critical crops such as wheat, soy, rice and corn, and in fact for every annual crop. There isn’t going to be any relief to be had for regions that are impacted by extreme weather.

    Even worse, atmospheric pollution is at such a level that trees are now dying all over the world. Weakened by ozone, they fall prey to rampant insects, disease and fungus. We are going to lose not only nuts, fruit, lumber and shade…the entire terrestrial ecosystem is collapsing.

    All anyone needs to do to verify this for themselves (believe me, the government won’t tell you, for fear of panic, and neither will the scientists, for fear of ridicule) is take a walk outside and really look at some actual trees.

    Their bark is cracking and splitting, holes are oozing sap, cankers like lethal tumors are growing on trunks, branches are snapping off, you can’t find a pine that you can’t see through because so many needles have fallen off. And there are so many that are already completely dead.

    Don’t let anyone tell you it’s because of insects, disease, and fungus. That’s like blaming a smoker’s lung cancer on eating too many potato chips.

    We should make drastic cuts in burning fuel, and ration its use for only the most essential purposes, before there is widespread famine, and riots in the empty grocery stores.

    More info here:

  2. BA says:

    This image from the NASA Earth Observatory site shows the extent of land where agriculture takes place. It says 40% of the earths surface but it looks like less to my eye. Combine the vulnerability of those areas with ocean acidification and crashing seafood stocks and it is not a pretty picture.

  3. David B. Benson says:

    I asgree that moisture maldistribution will indeed make agriculture increasingly difficult.

    Particulrly troublesome for me are the megafloods which wash away topsoil; productivity gone ‘forever’.