Tens of millions of people are moving to places that are more vulnerable to environmental disaster, particularly the urban flood plains of Asia and Africa, according to a UK government report.
By focusing mainly on the people displaced by drought, floods and famine, the world is neglecting those “trapped” in deteriorating environmental conditions or actually moving into them, says the study, prepared by the government’s Foresight programme that examines issues 20-80 years in the future.
The report is the outcome of a two-year study involving 350 experts from 30 countries, who produced 70 scientific papers of evidence and analysis.
It highlights that the problems of human migration in response to environmental change are far more complex and challenging than global policymakers have realised. But the report, which looks ahead for 50 years, urges policymakers to focus on the positive as well as negative impact of migration.
“Under some circumstances migration, particularly in low-income countries, can transform a community’s ability to cope with environmental change,” said Sir John Beddington, UK chief scientific adviser.
“The movement of individuals or small groups, even at a local or regional level, may increase the future resilience of large communities,” he added.
“This will reduce the risk of both humanitarian disasters and of potentially destabilising mass migration under high risk conditions.”
A relatively small example, which the report suggests should be a model for regional migration planning, is an offer by New Zealand to take in 75 people a year over the next 30 years from the low-lying Polynesian island nation of Tuvalu – equivalent to a quarter of the total population.
Migration can not only remove people from environmental danger but also provide new sources of income to help mitigate climate change. Remittances from migrants to families in low-income countries exceed $300bn a year, nearly three times the value of overseas aid.
“These kinds of income flows may actually make it possible for households … to stay in situ for longer,” Foresight said.
People already migrating are motivated by a complex mixture of economic, social, political and environmental factors.
The UN estimates that the world today has about 210m international migrants and 740m internal migrants who have moved within a country.
The study concluded that the uncertainties made it impossible to produce meaningful forecasts of future “environmental migration”. Others have issued estimates ranging from 150m to 300m people but these “rely on assumptions which are not supported by the evidence presented in this report”.
Global environmental change is likely to reduce the ability of many people to migrate and therefore will “in some circumstances reduce migration per se”, the report said. “These ‘trapped’ or ‘immobile’ populations are hidden from high-level estimates yet they represent a policy concern just as serious as, if not more serious than, migration.”
The World Bank said it would convene a meeting in December to discuss migration and environmental change “in view of the … issues covered in this Foresight report”.
The UK Department for International Development will use the findings to inform aid policy.