People who move for climate reasons need help in their new locations. In the United States, they struggle with meeting rent, health problems from the emergency, stress from moving, and lack of knowledge in navigating new health and financial systems. Globally, people displaced by disasters face food insecurity and challenges in transferring their livelihoods.

Most climate migrants go to cities, hoping to find economic opportunities and better infrastructure. However, many cities—particularly in developing countries—are already strained by population growth, underdevelopment, and poor planning. Public services like schools, transportation, and healthcare can quickly become overwhelmed. Cities projected to receive the most internal climate migration by 2050 are Bogota, Curitiba, Sao Paulo, Rio de Janeiro, Salvador, Amman, Karachi, Dhaka, Accra, and Freetown. 

But the cities themselves also get disrupted. A study of the U.S. Gulf Coast found that communities that received an influx of climate migrants after hurricanes Katrina and Maria faced their own challenges. Big population shifts affected housing markets, financial institutions, job availability, economic development, and social institutions. This was compounded by the uncertainty about whether the newcomers represented lasting population growth or not. 

A Threat Multiplier

There are 281 million international migrants, most of whom moved for economic reasons and through traditional visa processes. Although changes to climate alone might not drive most cross-border migration, they can act as a threat multiplier—meaning they can make other crises far worse.

Take the case of the ongoing Syrian refugee crisis, in which a fourth of Syria’s population has left the country. A drought between 2007 and 2010 caused migration from rural areas to Syria’s cities, which were ill-equipped to handle population growth, heightening tensions on top of economic problems. Arab Spring protests and a resulting government crackdown led to civil war.

In East Africa, a drought in 2022 led to food insecurity for 37 million people. Grain imports might have prevented hungry people from leaving, but Russia’s invasion of Ukraine (the source of most imported wheat in the region) reduced wheat imports.

The contribution of climate change to crises isn’t always obvious at the moment. We can see this at the U.S. southwestern border. A 2021 survey in El Salvador, Guatemala, and Honduras found that the primary considerations for migration to the United States were economic; only 5 percent of respondents mentioned climate as a reason for their decision. At the same time, 2020’s Hurricanes Eta and Iota and a 2018 drought decimated agriculture in the region, and migration increased after that. In other words, could survey respondents distinguish their economic problems from their climate problems? Have repeated disasters caused or worsened their economic problems?

In the end, the figures that matter about climate migration may not be headcount at all, but rather the lives lost or suffering that might have been prevented. We know that there are steps we can take now to avert the worst and prepare for the inevitable. The question is whether humanity can rise to the challenge.

Shelly Culbertson is a senior policy researcher at RAND and a professor of policy analysis at the Pardee RAND Graduate School. Culbertson's research focuses on disaster and post-conflict recovery, immigration and mass migration policy, refugees, global education, and international development. Follow her on X: @SC_Culbertson.

Image: Kazi Sharowar / Shutterstock.com.