Millions of migrants due to climate change

 By Robin Wylie

Climate change is expected to affect human life in some profound ways…

In order to adapt to the fluctuating temperatures, rising sea levels and extreme weather events that are predicted in the coming decades, human beings will be forced to develop new survival strategies. For many of the least fortunate people, this may involve searching for a new home.
Alongside the many possible consequences of climate change, experts are increasingly suggesting the potential for “climate migrants” — people who chose to relocate as a result of worsening climatic conditions at home.

A link between climate change and migration

The idea that climate change could lead to increased migration seems logical — after all, droughts, rising seas or devastating storms offer plenty of impetus for people to pack up and leave. However, demonstrating a link between climate change and migration scientifically has long proven tricky. But recently, a major study focusing on Europe found some of the most convincing evidence yet that climate change could lead to a rise in migration — and on a dramatic scale.
In the study, published In the journal Science in December 2017, researchers from the United States analyzed changes in asylum applications to the European Union between the years 2000 and 2014, and compared them to weather anomalies in the applicants’ countries of origin which had occurred during that time. After analyzing asylum applications from over 100 countries, the researchers discovered a statistically significant relationship between the number of applicants from a given country, and variations in temperature within that country. Specifically, they found that asylum applications to the EU were lowest in countries whose average temperature was around 20℃ (68℉), and increased when the weather was hotter or colder.
This was solid evidence that climate change did indeed have the potential to trigger a rise in migration. However, the researchers went a step further, and used their results, combined with climate change predictions, to look forward and estimate how future climate change could affect the flow of migrants to the EU.
They came up with some significant figures. For a global warming scenario, where global mean temperatures increase by between 1.7° and 3.2°C by the year 2100 (known as RCP 4.5), the researchers predicted that asylum applications to the EU would increase by 28 percent by that year (relative to the 2000-2014 yearly average of 351,000), to approximately 450,000 applications per year. But for a more extreme warming prediction, where temperatures rise by 3.2° to 5.4°C by 2100, they predicted a rise of 188 percent, equal to approximately 1 million applications per year.

People displaced by typhoon Haiyan. Philippines, 2013 (US Department of Defence)

The authors note that their estimates could be excessive, because they (obviously) cannot take into account future adaptations to climate change which might lessen the migration response. However, they also believe that the estimates might alternatively be too low, given that future climate change is likely to produce more extreme weather perturbations than it has in the past, which may induce greater levels of migration.
Although the numbers in this study are merely projections, they give some indication of the potential scale of climate change-driven migration in the future. The European Union is already struggling to adapt to the increasing numbers of migrants which are settling there, and if the trend were to increase significantly due to climate change, it could exert an even greater pressure on the continent’s already strained immigration services.

The world migration

Europe is expected to be one of most attractive destinations for climate migrants in the future, owing to its relatively high economic prospects, and the fact that the effects of climate change are predicted to be relatively minor there by global standards. However, climate change is also predicted to drive migration to various other parts of the world.
According to the Migration Policy Institute, a think-tank based in Washington D.C., climate change is expected to increase the rate of emigration from Mexico, Central America and the Caribbean toward the United States and Canada. Research suggests that the United States alone could receive up to seven million Mexican refugees over the next 70 years as a result of climate change.
And on the other side of the world, rising sea levels in the Pacific Islands are expected to send waves of climate refugees to places like New Zealand, whose government is currently considering a climate refugee” visa to accommodate future migrants.

High sea levels at Assateague island, USA (Howcheng, Wikimedia)

Yet while international migration is projected to increase as a result of climate change, the biggest movements of people will likely not occur across borders, but within individual countries. This can already be seen in places like Indonesia and Bangladesh, where people have been reported to migrate on a long-term basis when confronted with climate emergencies like prolonged heat and drought during key agricultural seasons, and Vietnam, where extreme weather events like floods or typhoons have been found to increase the likelihood that people will migrate internally.
On a global scale, there are also signs that climate change could be driving internal migrations towards urban areas. According to the United Nations Migration Director General William Lacy Swing, “climate change is… among the main reasons for the record numbers of people compelled to migrate from rural areas to towns and cities around the world.”
It is not yet possible to determine whether climate change is already affecting the numbers of human beings on the move. But with the rate of climate change currently exceeding the prediction of the most reliable computer simulations in many parts of the world, it is looking ever more likely that, in order to adapt to the consequences of an increasingly volatile atmosphere, more and more people will attempt to migrate to greener pastures in the coming decades.
According to the UN Food and Agriculture Organization, there were 244 million international migrants in 2015, 40 percent more than in 2000. As climate change kicks into gear, we may well see these numbers swell at an even greater rate. How our societies adapt to this new level of human mobility could be one of the defining challenges posed by climate change.

READ MORE: Climate change and migrations in South Africa by Nicholas Newman

about the author
Robin Wylie
Freelance earth/space science journalist. Currently finishing off a PhD in volcanology at University College London.