DW: The Syrian conflict started four years ago, in March 2011. You say that climate change contributed to the conflict. How is that?
There is a very clear sequence of events before the uprising, like an upward trend in temperature over the last 85 to 100 years. Within the last 25 years, three droughts have occurred. The last drought, just before the start of the conflict, lasted three to four years and was the most severe drought on record. So we asked: how severe would these droughts have been without the upward trend in temperature, which we presume to be human-induced? And we found that there was a big difference in severity. So this pointed to climate change as a contributing factor to this drought.
What was the impact of the drought?
The drought was so severe that it basically caused an agricultural collapse in the northeastern region. People there were highly dependent on wheat production. And when the drought occurred, the wheat production failed, so a lot of the farmers left their villages and a mass migration of people to the cities started. This was right after the US had gone into Iraq - so if you combine that with natural population growth, there was a tremendous population shock to the cities in Syria's west.
There was an increase in population of as much as 50 percent between 2002 and 2010. And the resources were just not sufficient to be able to deal with this population growth. The Assad government did very little to support this population as well. So, all these factors were coming together, and pushed them beyond their level of resilience.
You are able to scientifically quantify the temperature increase and the population increase. But how can you measure the role of climate change, compared to other factors such as the lack of freedom of speech, the Arab Spring in other countries, and so on?
It is very difficult, perhaps impossible, to quantify each of the effects that came together to cause the uprising. There is also very little information available about how many people went on to which city, because this information was also closely guarded by the Syrian government, and also because it was just a very chaotic situation.
We do have pretty reliable information about population estimates for the total increase. And it's not hard to imagine at all that if you do have that population increase, and you don't have sufficient resources to deal with this, how this can contribute to the uprising that occurred. Climate change acted as a threat multiplier - it pushed the various factors beyond a threshold.
What could have been done to prevent the conflict in this context?
We mentioned in the paper that a lot of factors contributed to Syria's level of vulnerability. For example, they had a very strong emphasis on wheat production, which was 25 percent of the gross domestic product. And after the drought, that number had plumped. And Syria went from being a net exporter of wheat to a net importer of wheat almost overnight.
Wheat production relies heavily on year-to-year rainfall - but also it relies strongly on the level of the groundwater. And groundwater went down in a very unsustainable way. But the Assad regime was not concerned about what might happen in the future, it was only concerned about trying to improve its economic position in the short term.
How does climate change impact the situation in Syria today, and what role will it play in the future?
Climate models suggest that this region is going to continue to become drier as the 21st century progresses - and that is certainly alarming. Even if the conflict were to end soon, this still presents a real problem for people like farmers, who are trying to put together a sustainable livelihood.
Which steps should be taken?
There needs to be an increase in long-term thinking, a real focus on the kinds of events that might occur frequently in the future. There has been a lack of that, and not only in Syria. Politicians only serve over a short period of time; they are not going to serve over 100 or 50 years. So there is much focus on the short-term future, and much less on the long-term future. I think that these kinds of [long-term] issues are really becoming more and more important.
Colin Kelley is a postdoctoral fellow at the Department of Geography at the University of Santa Barbara in California. He has done extensive research on climate change, and was the lead author on the study, which was published in the Proceedings of the National Academy of Sciences.Ruth Krause