Migration is a common strategy used by millions of rural households in less-developed countries facing daily and long-term challenges, including economic risk related to climate change. A migrant is a household member who moves to earn income elsewhere in the country or abroad and often sends a portion back home as remittances to help their family make ends meet.

New research supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) is exploring the role that environmental pressures play in migration decisions. Understanding the link between environment and migration and how policy shapes migration patterns can help inform programs to improve the well-being of rural families coping with climate pressures.

Extreme Weather Affects the Length of Migration

Weather shocks such as floods, droughts, heat waves, and cold snaps affect migration, but exactly how many people migrate, where they go, and for how long vary a great deal.

To understand these dynamics, Nathalie Williams of the University of Washington and Clark Gray of the University of North Carolina at Chapel Hill focus on rural Nepal using the Chitwan Valley Family Study’s 16 years of monthly residence data combined with more than 30 years of rainfall and temperature data.1

They examine types of migration (long or short term), the distance of migration (far or near), the type of weather shock (rainfall or temperature), the severity of the weather shock, and details of the family households.

Williams and Gray find that weather shocks are not linked to increased or decreased migration but rather are related to changes in the type of migration that occurs—resulting in less long-term and more short-term migration.

“Humans are incredibly responsive to adverse circumstances and can utilize multiple different adaptations and the character of their adaptations can also change with time and context,” they write.

In a related study, Williams teamed up with Barbara Entwisle of the University of North Carolina at Chapel Hill and Ashton Verdery of the Pennsylvania State University to examine migration dynamics during extreme floods and droughts in rural Thailand.2

Similar to the Williams and Gray study, they found that the type of migration was impacted by weather shocks. Out-migration increased very little, but they found decreased return migration. Those who do not return following extreme weather are therefore not home to leave again in the future, which provides one explanation for low levels of out-migration in response to climate change, the authors argue.

Environmental Policy to Protect Forests Impacts Migration in Rural China

As nations grapple with environmental destruction within their borders, programs offering payments for ecosystem services (PES) have emerged to slow deforestation and other damaging processes. Cash incentives to preserve or restore forests are an example of PES introduced in rural China in the 2000s. The programs were motivated by dramatic flooding in the 1990s linked to ongoing deforestation.

Qi Zhang of Boston University, previously of the University of North Carolina at Chapel Hill, and several colleagues examined the connection between migration and PES in rural China.Their investigation was based on a survey of households in Tiantangzhai Township in Anhui Province, a region in eastern China with rich natural resources but high levels of poverty. With rugged terrain and sloping land, the region offered an excellent opportunity for PES programs, given the environmental challenges facing farming households.

The research by Zhang and colleagues illustrates how environmental policy can impact migration. In fact, two different PES programs had two different impacts. One program provided farming households with either grain or cash incentives for converting cropland to forests. Another provided cash incentives and tax breaks for preserving existing forests for ceasing participation in commercial logging.

Migration increased from households that converted cropland to forests—less cropland means less demand for farm labor, allowing household members to migrate. In addition, the cash incentive covered the initial costs of migration, such as for transportation or housing.

In contrast, migration decreased in households that chose to preserve forestland. A possible explanation is that the cash incentives resulted in less need for remittance income from migrant household members. And since cropland was not affected, this type of program had no direct effect on the need for farm labor.

Zhang and colleagues believe that such insight “should be useful for the design of future incentive programs.” For instance, if a policy goal is to encourage more isolated farmers to move away from rugged mountainous regions, then local economic development to provide more off-farm employment would be more effective than large cash incentives to keep farmers on the land.

As climate change increasingly alters rainfall patterns across the globe, incentives such as PES may help protect nature’s buffers, such as forestland, against environmental destruction. Yet understanding the implications of different policies for migration is important for meeting social and environmental goals.

Child Grants Reduce Migration During Hot Spells in Rural Zambia

Across the world, child grant programs aim to improve children’s health and well-being. In Zambia, one such program targets 200 households in three rural districts characterized by extreme levels of illness and mortality among resident children. The child grant program provides US$11 per month, approximately one-third of a typical household’s monthly expenditures.

This region’s reliance on agriculture, which is greatly impacted by shifts in temperature and rainfall, make it also highly vulnerable to climate change. Migration to nearby cities is a common strategy to seek employment opportunities that may yield remittances to help those at home.

Valerie Mueller of Arizona State University, Clark Gray and Sudhanshu Handa of the University of North Carolina at Chapel Hill, and David Seidenfeld of the American Institutes of Research examined how the Zambia child grant program along with temperature and rainfall influenced migration.4

Data from nearly 5,000 surveys revealed that during times of average temperature and rainfall, households receiving child grants had more male family members migrate long distance than those without such grants. As in rural China, the extra cash may cover initial migration costs such as transportation and housing, helping vulnerable households seek new income sources.

However, environmental pressure such as hot spells kept potential migrants home even if the household received the child grant. During these times, the additional cash was unable to support migration, and vulnerable households became trapped by especially challenging weather conditions.

Studies such as this one offer important insight on the three-way connection between policy, migration, and environmental conditions. Such insight can help policymakers make programmatic changes to lessen rural households’ vulnerability to extremes in climate—such as adjusting the amount and duration of cash transfers.

Environmental and Health Policies Can Influence Migration as a Response to Climate Pressures

The examples in rural China and Zambia underscore the importance of thinking broadly about policy impact. Interventions targeting one area such as environment or health have ripple effects in other aspects of household well-being. Such ripple effects may offer co-benefits, such as reducing poverty.

For example, cash incentives or grants—even if not explicitly targeting migration—can enhance the ability of a household member to migrate to diversify their family’s income sources. A migrant’s remittances can help reduce poverty back home. Even so, cash incentives and grants may be insufficient to keep households from being unable to move during especially challenging climate conditions. In these cases, more targeted policy may be required, such as directly encouraging migration by reducing barriers to employment in destination areas.

This article was produced under a grant from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). The work of researchers from the following NICHD-funded population dynamics research centers was highlighted in this article: Pennsylvania State University (5P2CHD041025-19), University of North Carolina at Chapel Hill (5P2CHD050924-15), and University of Washington (5P2CHD042828-18).




  1. Nathalie E. Williams and Clark Gray, “Spatial and Temporal Dimensions of Weather Shocks and Migration in Nepal,” Population and Environment 41, no. 3 (2020): 286-305.
  2. Barbara Entwisle, Ashton Verdery, and Nathalie Williams, “Climate Change and Migration: New Insights from a Dynamic Model of Out-Migration and Return Migration,” American Journal of Sociology 125, no. 6 (2020): 1469-512.
  3. Qi Zhang et al., “Determinants of Out-Migration in Rural China: Effects of Payments for Ecosystem Services,” Population and Environment 40, no. 2 (2018): 182-203.
  4. Valerie Mueller et al., “Do Social Protection Programs Foster Short-Term and Long-Term Migration Adaptation Strategies?” Environment and Development Economics 25, no. 2 (2020): 135-58.