War-related climate change would substantially reduce crop yields

Though worries about "nuclear winter" have faded since the end of the Cold War, existing stockpiles of nuclear weapons still hold the potential for devastating global impacts.

Researchers at the University of Wisconsin–Madison and Rutgers University have found that the climate effects of a hypothetical nuclear war between India and Pakistan would greatly reduce yields of staple crops, even in distant countries.

The work, by Mutlu Ozdogan and Chris Kucharik of the Center for Sustainability and the Global Environment in the Nelson Institute for Environmental Studies at UW–Madison and Alan Robock of Rutgers' Center for Environmental Prediction, will appear in an upcoming issue of the journal Climatic Change.

Robock used global climate models to calculate the climate impacts of a conflict between India and Pakistan, each using 50 .

"This is essentially a climate change experiment, but instead of running a climate change model under a global CO2 scenario, you run it under a soot scenario, where the soot comes from fires from cities and industrial areas burning as a result of the war," explains Ozdogan, a UW–Madison professor of forest and wildlife ecology.

The soot and smoke can travel around the world in the atmosphere and block some of the sunlight that would normally reach the Earth. That leads to cooler temperatures, altered weather and precipitation patterns, and shorter growing seasons.

"We were surprised that there was such a large climate change – unprecedented in recorded human history – even from a war with 50 small nuclear weapons per side, much, much less than one percent of the current nuclear arsenal," says Robock. He adds that the changes also lasted a full decade, much longer than he expected. "The question is, what impact does that have on things that matter to humans, and the most important is our food supply."

The researchers used the climate changes predicted for the Midwest to calculate potential effects on corn and soy production in Iowa, Illinois, Indiana and Missouri. Using climate-based agricultural output models, they compared yields under modern weather patterns and under the war scenario.

They found that the climate effects of nuclear war led to decreases in corn yields of 10 to 40 percent and soy yields of 2 to 20 percent, with the reductions gradually declining over the course of the decade following the war.

"Those changes – in any year – are much larger than the natural variation we might see" due to weather fluctuations alone, Ozdogan says. And unlike gradual environmental changes associated with greenhouse gas accumulation, the rapid onset of a war would not permit farmers or the global economy any time to adapt.

A companion study by Robock and Lili Xia of Rutgers University, also published in Climatic Change, calculated that the same scenario would dramatically reduce rice production in China: an average decrease of 21 percent during each of the first four years after the war and 10 percent less for the next six years.

Such losses add up to a huge impact on regional food supplies that could escalate into wider food shortages and trade breakdowns with dire economic and political consequences, Robock says.

The take-home message, Ozdogan says, is that localized events can have disproportionately large global impacts.

"Hopefully this will never happen," he says, "but if it happens, if the prospect is there, these are some of the results that people could expect."

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Citation: War-related climate change would substantially reduce crop yields (2012, July 2) retrieved 20 October 2019 from https://phys.org/news/2012-07-war-related-climate-substantially-crop-yields.html
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Jul 02, 2012
This study would be more helpful if they put their estimates in a "per kiloton detonated" ratio.

Just saying "a war between Pakistan and India" isn't very helpful at all. A war could consist of two 50 kiloton weapons being detonated....in which case one would be hard pressed to find any global environmental impact.

Jul 02, 2012
War-related climate change would substantially reduce crop yields
You would have to factor in the associated population reduction in the most populous region in the world, and the decreased consumption of fossil fuels over a few generations which would result.

Jul 02, 2012
Promoting war between India and Pakistan was one of the ways the NeoConsrevative "thinkers" at PNAC (Project for a New American Century) had promoted as a means of reducing the economic threat to America from India...I guess you can't keep the American death mongers down.
The US, pakistan, and india are already smaller Parts of a much bigger Whole. If a war like this needs to be fought, then it is They who would be Planning it, Staging it, Managing it, and Arranging for the most fortuitous Outcome.

Remember when Hulk Hogan the good guy with all his little hulksters became Hollywood Hulk Hogan the bad guy? Remember when jessi the body ventura became governor of wisconsin? Remember when ronald reagan the actor became president of the US? Remember when jane fonda convinced a few 100 thousand NVA and viet cong to throw themselves on the wire during Tet, so the US could finally leave? As always, thanks jane.

Its like that only Bigger. Much Bigger.

Jul 02, 2012
THEY are the ones who arranged the partition of india and pakistan which resulted in a few million dead. It was THEY who enabled the 2 countries to acquire nuclear arms, making continued western involvement in the region imperative. It was THEY who anticipated the threat of a pan-moslem caliphate with the potential to possess nuclear arms, and so made 9/11 and the iraq and afghan wars Inevitable.

Because it was THEY who invented the great religions to begin with, so as to conquer and subdue the world by dividing the people up and setting them against each other in Orderly and Constructive Ways.

The people are the true enemies of rulers everywhere.

Leaders reached this unavoidable Conclusion a few millenia ago. They only had to decide to ACT, in concert. A new Tribe was born; and the rest, as They say, is history.

Jul 02, 2012
You have to wonder why Conservative Inferiors allow themselves to be so easily duped by their NeoConservative brothers.

I blame their lack of a good Liberal Education.

"Its like that only Bigger. Much Bigger." - Otto
You have been Divided and Conquered. Liberal... conservative... either way, you Serve.

Win win.

Jul 03, 2012
I am neither Liberal or Conservative.
Sorry you still Serve. You cannot NOT Serve. You are a cow in a pen, a pig in a poke.

Deny it? They KNEW you would do that. Typical for your Category.
Who are "THEY"?
Doesnt matter. It only matters what They do and Why. This is how we can tell that Theyre there.
Did "THEY" set China up as the worlds biggest economy?
Of course.
Are "they" currently plowing Europe's economy into the ground?
Certainly. How else are you going to form a United States of Europe?
Were "they" camping in Colorado...deliberately leaving their fire unattended?
Maybe. A forest has evolved to be self-sustaining. Natural fires clean out the underbrush and kill parasites.

But humans prevent these natural fires, so that when they Inevitably occur, they threaten to destroy the forest completely. So Controlled burns MUST Occur.

See the analogy? Leaders not only start fires, They start wars. For tinder they invent religions. WE are the Enemy.

Jul 03, 2012
I am neither Liberal or Conservative.

Sorry you still Serve. You cannot NOT Serve. You are a cow in a pen, a pig in a poke.
They have learned in the course of a few millenia, to use 'everything but the squeal', as they say.


"'Everything but the squeal' is a quote attributed to the meat-packing industry and it was first signalled in Upton Sinclair's 1906 novel, the Jungle ..."

-A very Informative bit of Propaganda. They are everywhere and everything. Just like Joseph and pharaoh, all you need to know in order to own everything, is the future.

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