Refugee crisis: Is climate change affecting mass migration?

John Kerry painted an apocalyptic vision of climate change last week as he addressed a global warming conference in Alaska. "You think migration is a challenge in Europe today because of extremism, wait until you see what happens when there's an absence of water, an absence of food, or one tribe fighting against another for mere survival," the US secretary of state warned. Few experts would argue with Kerry's analysis of the future, but some would argue his vision is already upon us.

The current refugee crisis marks a watershed moment in the history of global warming because it's the first wave of emigration to be explicitly linked to climate change, according to one leading scientist, who predicts rises in temperature and increasingly extreme weather will unleash many more mass movements of people in the future. Professor Richard Seager acknowledges that there is much more to the Syrian uprising than the climate, but says that global warming played a key role in creating the conditions that fuelled the civil war behind the refugee emergency.

"Syria was destabilised by 1.5 million migrants from rural communities fleeing a three-year drought that was made more intense and persistent by human-driven climate change, which is steadily making the whole eastern Mediterranean and Middle East region even more arid," says Professor Seager, of Columbia University in New York, who published a report into the role of climate change in the Syrian conflict in March. "Syria is not the only country affected by this drying. Lebanon, Jordan, Israel, Iraq and Iran are too. However the various social, religious and ethnic wars play out, in the coming years and decades the region will feel the stress of declining water resources."

East African countries such as Somalia and Sudan are also vulnerable to drought-fuelled conflict, according to Professor Seager, along with parts of Central America – especially Mexico, which is afflicted by crime and is politically unstable, short of water and reliant on agriculture.

But pushing regimes that are already unstable, poor and short of resources into conflict is only one way in which climate change is heralding a new era of mass environmental emigration. "In the future climate change is going to cause humanitarian crises of a different type and dynamic, but they're going to be just as real and a catastrophic as the present refugee crisis," says Neil Adger, professor of human geography, at the University of Exeter. Dramatic increases in the frequency and intensity of extreme weather, particularly from drought and floods but also from wildfires, are forecast for the coming decades, Professor Adger warns, while rising sea levels will pose a risk to coastal areas, especially low-lying delta areas such as Burma and Louisiana.

Africa is another continent likely to suffer disproportionately from climate change. "In sub-Saharan Africa we're likely to see increased incidence of drought, lower crop yields and food price spikes in years to come, adding to pressures on communities that are already living with other stresses and where population is increasing," saysRichard Black, director of the Energy and Climate Intelligence think tank.

Meanwhile, the Sahel band of desert, stretching from Senegal in the west to Eritrea in the east, and including parts of Mali, Niger, Burkina Faso and Nigeria, is forecast to suffer huge levels of displacement. A recent report from the group Organising to Advance Solutions in the Sahel suggested that over the next three to four decades up to 200 million people are likely to be without sustainable food supplies. This assumes that temperatures in the region rise by as much as 5C by 2050, with the population expected to grow from about 100 million now, to 300 million in 2050 and 600 million by the end of the century.

"It would be totally implausible to sustainably accommodate this scale of growth," said the report. "Without immediate, large-scale action, death rates from food shortages will rise as crops wither and livestock die, and the largest involuntary migration in history could occur."

Such warnings are speculative, of course. But the scale and misery of the current crisis should act as a warning, reminding us that, when millions find that they can no longer live safely or tolerably in their own lands, people in supposedly unaffected nations soon feel the effects.

IS CLIMATE CHANGE EXACERBATING THE REFUGEE CRISIS?

161

The number of countries in which environmental disasters, most of them due to weather-related events, have caused mass displacement of people since 2008

27m

The average number of people displaced by environmental disasters each year between 2008 and 2013

350,000

migrants sought entry into the EU in 2014 but this could rise to 200 million when the full impact of climate change is felt