143MProjected internal climate migrants by 2050
45°C+Phoenix summer danger threshold days exceeded annually
30+Days/year Phoenix exceeds 45°C danger threshold
3Regions: Sub-Saharan Africa, S. Asia, Latin America at highest risk
Climate change is making some places too hot, too dry, or too flooded to live in. Scientists predict that by 2050, 143 million people — almost half the population of the United States — will have to move to survive. Unlike war refugees, they won't cross borders. They'll just move within their own country. And there's almost no plan for this.
The World Bank's Groundswell report modeled three climate scenarios across Sub-Saharan Africa, South Asia, and Latin America. Under a high-emissions scenario, 143M people become "climate migrants" by 2050 — driven by water stress, crop failure, and sea level rise. This is internal displacement, not international refugee flows. Phoenix, AZ already exceeds 45°C (113°F) for 30+ days/year, threatening outdoor workers, elderly, and low-income residents who can't afford AC.
World Bank Groundswell (2021) uses integrated climate-economic model with SSP2 pathway (middle-of-the-road development). Pessimistic scenario: 216M internal migrants. Methodological note: Rigaud et al. define "climate migrant" as forced relocation due to slow-onset hazards (drought, sea level, ecosystem disruption) — not rapid-onset disaster. Phoenix data from NOAA GHCN-daily: frequency of days ≥45°C increased from avg 4 days (1970-1990) to 31 days (2020-2024). Heat island effect compounds: urban Phoenix is 3-4°C hotter than surrounding desert. Housing stress: climate-vulnerable zones correlate with lower property values — underwriting climate gentrification.
World Bank Groundswell Report 2021: openknowledge.worldbank.org/handle/10986/36248. NOAA Phoenix climate data: ncei.noaa.gov. Phoenix heat mortality data: Maricopa County Public Health annual heat reports. Climate Displacement Monitor: idmc.ch. FEMA National Risk Index: msc.fema.gov/portal/resources. EPA Climate Change Indicators: epa.gov/climate-indicators. Internal Displacement Monitoring Centre (IDMC) 2024 Global Report on Internal Displacement.
The Migration Pressure Map
Climate displacement doesn't happen suddenly — it's a slow accumulation of unbearable conditions. Water disappears, crops fail, summers become lethal.
Projected Climate Migrants by Region (2050)
World Bank Groundswell model — high-emissions scenario (SSP2)
Phoenix: Days Over 45°C (1970–2024)
Extreme heat days are accelerating beyond historical norms
US Internal Climate Risk Factors (2024)
Millions of Americans already living in high-risk climate zones
Internal Migration Has No Refugee System
International refugee law covers people who cross borders. Internal climate migrants — who move within their own country — have no legal protections, no international aid system, and no right to resettlement assistance. 143 million people are heading toward displacement with no net to catch them.
Sources
World Bank Groundswell Report (2021) · NOAA National Centers for Environmental Information · Maricopa County Public Health Heat Mortality Reports · FEMA National Risk Index (2024) · Internal Displacement Monitoring Centre Global Report (2024)