Extreme weather events, especially drought, have increased the flow of refugees so far this century. In a study with climate data, wars and revolts and asylum seekers, a group of researchers has verified that there is a causal link between climate change and the increase in asylum mediated by an increase in conflicts. However, no matter how intense a drought is, it does not always lead to a war and it is a mass migration.
In recent decades there have been several waves of migration in which the conflict in the first place and the climatic conditions would ultimately have had much to do. Many of the migrants who have arrived in the southern European countries in these years, from Greece to Spain, can not be easily labeled as economic migrants. They come from countries where revolt, if not war, is present. And, if you look further back, there are possible climatic triggers. Perhaps the case of Syria is the best known, but it is not the only one. The problem, for scientists, is to prove that there is a causal relationship between the three phenomena (climate event, conflict and migration) and not a mere temporal succession.
Now, a group of European researchers has started from the data of asylum seekers from 157 countries of the United Nations High Commissioner for Refugees (UNHCR) to rewind on the trip, going back in time and to the geographical origin of those refugees. Once located, they used the SPEI index, prepared by Spanish scientists, to determine and assess the duration and intensity of droughts in the years preceding the possible outbreak of a conflict. For the latter, they used the statistics on revolts and armed conflicts maintained by the Center for Peace and Conflict Research of the University of Uppsala (Sweden).
The study shows a causal relationship between climate event, conflict and asylum in some events but not in others
"We have found not only a correlation in time, but a causality in the chain of events," the professor of economics at the University of Vienna and co-author of the study, Jesús Crespo, said in a telephone conversation. "In the last decade, between the climate, the conflicts and the ensuing forced migrations, there is this causal relationship," he adds.
The effect of climate on conflicts was more marked in the countries of the Middle East, especially between 2010 and 2012. It is the period of Arab Spring, which shook like a tremor from Tunisia to Yemen, passing through Libya or Syria. The case of the latter country is, for the duration of the conflict and the number of people who left their land, the most prominent. There, the revolts began in March 2011, but the conditions for the outbreak must be sought before.
Between 2007 and 2010, Syria suffered one of the worst droughts in its history. Aggravated by a terrible management of water resources, the consequence was a succession of bad harvests. This pushed a good part of the rural population to migrate to the cities: the urban population went from 8.9 million to 13.8 million in just eight years. Overpopulated suburbs in a context of economic crisis and high cost of living must have influenced the beginning of the revolts against the Al Assad regime. The same pattern appears in several countries in sub-Saharan Africa, such as South Sudan.
But that causality is not universal. "We find it in the phenomena that happened in the last decade, but not in the previous years," says Crespo. The work, published in the magazine Global Environmental Change, begins in 2006. However, there is a drought, torrential rains or hurricanes does not mean that they always trigger a conflict that ends with a wave of migration.
Conflicts in Syria or South Sudan would have a climate trigger but not those in Chechnya or Angola
Thus, although the greater or lesser severity of the drought appears related to the appearance of several conflicts between 2011 and 2015, the same does not happen in the previous five years. In those years there were revolts and wars in countries such as the Democratic Republic of the Congo, Somalia, Chechnya, Angola or Iraq that do not seem related to the drought or that did not produce massive migrations. "Of course, our results do not indicate that climate change has had nothing to do with these conflicts, but there is no evidence of a systematic causal relationship in these years," Crespo recalls. The explanation may lie in other elements that are not environmental. "It would take new studies, but everything suggests that the level of democracy of a country or the quality of its institutions are also factors that intervene", concludes the Spanish researcher.