Effects of climate migration on town-to-city transitions in the United States: proactive investments in civil infrastructure for resilience and sustainability

Abstract

Abstract Climate change is a hazard risk amplifier and contributes to changing precipitation and temperature patterns that alter an area’s risk profile. Existing infrastructure is often ill-equipped to absorb shocks associated with increased hazard frequency and severity, but active measures to implement holistic resilience plans are rare and often limited in scope. As climate change progresses, climate change-induced migration is becoming more frequent and likely, with probable changes to regionally specific needs for resilient infrastructure. People relocating to areas with actual or perceived lower risk is expected to add demand for built infrastructure and change governance needs as receiving communities grow. Anticipating demand growth can enable proactive rather than reactive investment. Here we analyze the impact of anticipated climate migration patterns on community growth in the United States (US), leveraging the US Environmental Protection Agency’s Integrated Climate and Land-Use Scenarios dataset to illustratively evaluate how domestic migration might alter regional patterns for a particularly salient target of infrastructure planning: ‘tipping points’ where towns become cities and experience qualitative changes in infrastructural and governance complexity. Projected 2010–2100 town-to-city rapid urbanization patterns are different from historical (1950–2010) patterns in the US, notably shifting from the Southwest (including California) to the Southern Plains (including Texas). Climate change is expected to shift this pattern north and east, contributing to land use change and new demand for civil infrastructure in places where past development strategies might not be regionally appropriate. Urban futures are not predetermined: this illustrative analysis highlights that despite deep uncertainty, sufficient information about climate change, migration patterns, and generalizable best practices for infrastructural development exists to support proactive planning for migration. Proactive and regionally appropriate investment in civil infrastructure in regions expected to attract climate migration can facilitate resilience, sustainability, and justice under climate change, emphasizing safe, sufficient, and equitable infrastructure.