Climate change is expected to displace millions of people through impacts including sea level rise, crop failures, and more frequent extreme weather.

Scientists still cannot predict where these expected climate-induced migrants are likely to go in the coming decades but they are starting to get a picture of where they will come from.

Two new studies show that South Asia could be a hot spot for climate driven diaspora.

A study published recently in the journal Environmental Research Letters, has used a probabilistic model combined with population, geographic, and climatic data to predict the sources, destinations, and flux of potential migrants caused by sea level rise.

The study focused on the case of sea level rise (SLR) and human migration in Bangladesh, where the authors estimate that more than two million Bangladeshis may be displaced from their homes by 2100 because of rising sea levels alone.

Lead author Dr Kyle Davis, of Columbia University, said that more than 40 per cent of Bangladesh’s population was especially vulnerable to future sea level rise, as they live in low-lying areas that are often exposed to extreme natural events.

“However, SLR is a very different type of migration driver from short-lived natural hazards, in that it will make certain areas permanently uninhabitable,” he said.

The team’s results using Representative Concentration Pathway (RCP) scenarios showed that mean SLR will cause population displacements in 33 per cent of Bangladesh’s districts, and 53 per cent under more intensive conditions.

By mid-century, they estimated nearly 900,000 people are likely to migrate because of direct inundation from mean SLR alone.

Under the most extreme scenario, of up to two metre mean SLR, the number of migrants driven by direct inundation could rise to as many as 2.1 million people by the year 2100.

The researchers also estimated the extra jobs, housing and food needed to accommodate these migrants at their destinations would amount to 600,000 additional jobs, 200,000 residences and 784 billion food calories by 2050.

These results have clear implications for the places that are likely to receive incoming migrants.

“SLR migrants are unlikely to search far for an attractive place to move to, and the destination will generally be a trade-off between employment opportunities, its distance from the migrants’ origin, and how vulnerable it is to SLR itself,” the researchers said.

“We found that the city of Dhaka was consistently favoured, coming out as the top destination in all scenarios. This means the city will need to prepare for the largest number of migrants, which may compound the area’s already rapid urban growth” they said

The study also identified other risks from SLR, most notably on livelihoods and food security.

“Inundation by the sea, and the out-migration it causes, will have significant effects on agriculture and aquaculture. For instance, 1000 square kilometres of Bangladesh’s cultivated land could be underwater by the end of the century, with an even larger area made unusable by saltwater intrusion,” the researchers said.

Another study produced by Delhi University researchers Professors Simrit Kaur and Harpreet Kaur also identified South Asia as being particularly vulnerable to climate change.

“South Asia is particularly vulnerable to climate change. Nearly half of the region’s population lives in areas that are projected to become moderate to severe by 2050,” the researchers said.

They pointed to climate change already contributing to declines in agricultural production, productivity and food security.

And they said natural calamities such as floods, tsunamis and earthquakes had increased the susceptibility of the region’s already vulnerable population.

“Migration has emerged as an important survival and adaptation strategy. In Bangladesh alone, 15 million people are expected to be displaced due to the environmental degradation of the coastal zone. The bulk of forced climate-induced migration has involved the most vulnerable.

“Empirical evidence suggests that environmental degradation is an important factor in pushing migration, particularly in less developed countries,” the researchers said.

They said that forced migration could also exacerbate ethnic tensions.

“With climate change already impacting the availability of water, food and arable land in host countries, transboundary migration is expected to trigger conflicts and exacerbate tensions. Migration also contributes to ethnic tensions, discords, distrust and the demolition of social capital,” they said.

“For instance, many illegal Bangladeshi immigrants are seeking employment in India. This is leading to rising Indian intolerance towards Bangladeshis, especially in Assam and West Bengal.

“The presence of Nepali migrants in Bhutan and India, Sri Lankan Tamils in India and Chakmas in Bangladesh have increased security issues for these countries,” the researchers said.

The research pointed to two issues around climate-induced migration that need discussion.

“First, there are no official definitions of climate-induced migration or displacement at the international level. Second, the negligible data on climate-induced migration inhibits the design of effective resilience and adaptation policies, especially for trans-boundary migration,” the researchers said.

“It is thus important to invest in data and analysis to understand migration patterns and trajectories,” they said.

Laurie Nowell
AMES Australia Senior Journalist