Climate Change Exacerbates Flood Risk, Driving Local Migration Trends: Report
Climate change is having a significant impact on population trends in cities across the United States, including San Antonio and Bexar County, Texas. According to a recent report by the First Street Foundation, a data nonprofit focused on communicating climate hazards, 17 percent of the city’s blocks experienced a decrease in population as the area grew by over 600,000 people in the last two decades.
The primary driver of this population decline is flood risk, which is exacerbated by climate change. Bexar County, located in Flash Flood Alley, is part of a national trend of hyper-local migration to avoid flooding, leading to the hollowing out of blocks within cities. The report, based on a model published in the journal Nature Communications, analyzed granular U.S. Census Bureau data and controlled for factors like job opportunities and school quality.
Between 2000 and 2020, 3.2 million Americans moved away from high-flood-risk areas, with many staying within close proximity to their previous homes. This migration has significant downstream implications, impacting property values, neighborhood composition, and commercial viability. The analysis predicts that vulnerable areas will continue to lose population over the next 30 years.
The increase in disasters causing at least $1 billion in damages in the U.S. has also contributed to the trend of climate migration. Global warming has led to more frequent and severe flooding events, including sea level rise, intense hurricanes, and prolonged downpours. While climate migration is occurring in various regions, the focus of the First Street report was specifically on flooding, as it is the most common weather-related disaster.
The researchers found that even a small percentage of properties at risk of flooding in a census block can trigger population movement, regardless of other amenities like coastal views. This migration has led to both declining and slowed growth in affected areas. In Bexar County, neighborhoods with lower flooding risk experienced faster growth compared to those with higher risk.
While some experts question the primary role of flooding in migration decisions, the First Street model effectively isolated the impact of flooding on population trends. Factors like job opportunities and family proximity often play a larger role in relocation decisions. Despite the complexity of motivations for moving, the data supports the conclusion that climate change-induced flooding is influencing population shifts in cities nationwide.
In conclusion, the data-driven analysis by the First Street Foundation sheds light on the impact of climate change on local population dynamics, highlighting the need for proactive measures to address flood risk and mitigate the consequences of climate-induced migration.
A new report by the First Street Foundation reveals that over the last two decades, some 17 percent of blocks in San Antonio and Bexar County, Texas, have experienced a decrease in population due to flood risk exacerbated by climate change. This trend is part of a national pattern of hyper-local migration to avoid flooding, which is causing certain neighborhoods to hollow out within cities. The research, published in the journal Nature Communications, uses granular U.S. Census Bureau data to analyze population changes and factors in flooding, job opportunities, and school quality.
Between 2000 and 2020, 3.2 million Americans moved away from high-flood-risk areas, with most not moving far. This migration has significant downstream implications on property values, neighborhood composition, and commercial viability. The analysis predicts that vulnerable areas will continue to lose population over the next 30 years. The increase in billion-dollar disasters in the U.S. is attributed to global warming, which leads to more frequent and severe flooding events.
While climate migration is occurring in various regions, quantifying the impact of climate change on migration at the neighborhood level has not been done on a national scale before. First Street’s model focuses on floods as the most common weather-related disaster and found that even a small percentage of properties at risk of flooding can trigger people to move out, impacting neighborhood growth and decline. In Bexar County, neighborhoods with lower flooding risk experienced faster growth compared to those with higher risk.
Although the First Street model has been praised for isolating the signal of flooding on migration, some experts, like Kristina Dahl from the Union of Concerned Scientists, point out that environmental factors are typically low on the list of reasons for moving. Factors like job opportunities and family proximity often play a more significant role in relocation decisions. Overall, the impact of flood risk on neighborhood-level population change highlights the complex interplay between climate hazards, migration patterns, and socioeconomic factors.
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