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Did Climate Change Tip Syria Into War?

Climate change from 2006 to 2010 may have helped exacerbate the economic and social collapse that led to today's bloody Syrian conflict. Continue reading →

We're accustomed to thinking of revolutions and wars as being caused strictly by human conflict. But a new study suggests that climate change may have played a role in causing the 2011 uprising against the regime of Syrian dictator Bashar al-Assad, by causing catastrophic crop failures and population movement that helped push Syrian society to the breaking point.

"We're not saying the drought caused the war," said Richard Seager, a climate scientist at Columbia University's Lamont-Doherty Earth Observatory, who coauthored the study published on Monday in Proceedings of the National Academy of Sciences."We're saying that added to all the other stressors, it helped kick things over the threshold into open conflict. And a drought of that severity was made much more likely by the ongoing human-driven drying of that region."

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This isn't the first time that climate change has been cited as a major factor in a nation's collapse. Drought, possibly intensified by the clearing of forests for wood and farmland, also was a likely factor in the disappearance of a highly-developed Maya civilization in central America around 1,100 years ago, according to several studies.

But Syria might be the first modern instance of a societal collapse caused by climate woes. Seager and his colleagues found that since 1900, the Fertile Crescent - a region that includes much of Syria, Iraq and Turkey - has heated up by about 2 degrees Fahrenheit, and seen a 10 percent reduction in rainfall.

Those trends can't be attributed to natural climate variability, and match closely with models of human-influenced climate change, the researchers say.

Those environmental changes helped to magnify other long-term problems, including more than five-fold population growth in Syria since the 1950s, and misguided agricultural policies that encouraged the cultivation of water-intensive crops such as cotton.

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The disastrous drought caused agricultural production to plummet and wiped out livestock, which caused food shortages and drove up prices. Destitute, starving rural dwellers abandoned the fields and fled to the cities, which already were strained by an influx of refugees from war-torn Iraq.

Data suggests that global warming caused the decrease in precipitation, by weakening wind patterns that might have brought moisture-laden air from the Mediterranean. Additionally, the higher temperatures increased evaporation of soil moisture. The resulting one-two punch led to the longest, most severe drought in more than a half century.

Rising discontent led protesters - inspired by Arab Spring uprisings against repressive regimes elsewhere in the Middle East and North Africa - to take to the streets in early 2011. After the Assad regime responded with brutal repression, an armed conflict erupted.

Initially, rebel forces seized control of large swaths of the country, but by 2013, the war began to shift in favor of the better-armed and better organized Assad forces. The chaos allowed a third force, the terrorist group ISIS, to grab extensive territory and spread into Iraq.

A destroyed tank sits idle on a street in Aleppo, Syria, in 2012.

The effects of global warming are frequently projected decades into the future, but two recent reports -- one from the

U.S. Global Change Research Program

and the other

from the U.N.

-- put into sharp focus visible consequences of our warming planet. An increase in temperature, extreme weather, loss of ice and rising sea level are just a few of changes we can measure right now. Let's take a look at some of the most concerning trends.

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Glaciers are shrinking worldwide and permafrost is thawing in high-latitude and high-elevation areas, reports this year's Fifth Assessment Report from the Intergovernmental Panel on Climate Change.

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Only a few extinctions are attributed to climate change, reports the IPCC, but climate change that occurred much more slowly, over millions of years, caused major ecosystem shifts and species extinctions. Land and sea animals are changing their geographic ranges and migratory patterns due to climate change.

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Sea level around the world has increased by about 8 inches since 1880, reports the 2014 National Climate Assessment, which projects a 1 to 4 foot rise by the end of the century.

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Excess CO2 is dissolving in the ocean and decreasing the pH of seawater. The ocean is about 30 percent more acidic than it was in pre-industrial times. More acidity in the oceans makes it harder for animals to form calcium carbonate shells and skeletons and erodes coral reefs.

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The probability of a Sandy-like storm deluging New York, New Jersey and other parts of the East Coast has nearly doubled compared to 1950, according to the American Meteorological Society. Even weaker storms will be more damaging now than they were 10 years ago because of rising sea levels. Superstorm Sandy cost the nation $65 billion, according to the 2014 National Climate Assessment, and 2012's Hurricane Isaac cost $2.3 billion.

The global sea level rises along with the temperature for two major reasons. For one, heat causes water to expand, which causes the existing water to take up more space and encroach on the coast. At the same time, ice at the poles and in glaciers melts and increases the amount of water in the oceans.

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Across the United States, heavy downpours are on the rise, especially in the Northeast and Midwest. Increases in extreme precipitation are expected for all U.S. regions, reports the 2014 National Climate Assessment.

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The most recent IPCC report states with "very high confidence" that current climate-related extremes like heat waves, droughts, floods, cyclones and wildfires are showing that countries around the world, at all development levels, are significantly unprepared. The American Meteorological Society estimates that approximately 35 percent of the extreme heat in the eastern United States between March and May 2012 resulted from human activities' effects on climate. The AMS warned that deadly heat waves will become four times more likely in the north-central and northeastern United States as the planet continues to warm.

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