Minnesota needs to prepare for extreme heat and the urban heat island effects
Minneapolis is particularly vulnerable to urban heat islands, with roads, parking lots, and other impervious surfaces accounting for nearly 50% of the city’s land area. Photo by Getty Images.
Recent Minnesota summers have brought warmer temperatures, drought conditions, and — due to Canadian wildfires — air quality issues. On August 23rd, the Twin Cities broke a 1948 heat record when temperatures reached 98 degrees at MSP airport. This Labor Day weekend, the Twin Cities tied longstanding heat records.
Urban communities are experiencing so-called urban heat island effects, which are caused by hot, heat-absorbent surfaces, such as parking lots and roads, that elevate local surface temperatures. Minneapolis is particularly vulnerable to urban heat islands, with roads, parking lots, and other impervious surfaces accounting for nearly 50% of the city’s land area.
The map below shows this effect in the Twin Cities region, with Minnesota Pollution Control Agency data showing areas with a higher percentage of low-income residents and residents of color.
The urban heat island effect profoundly impacts human health, with burdens disproportionally falling on marginalized communities. A 2017 study found that heat islands were generally less severe in areas with higher median income and a higher population of white residents. Black and lower-income residents generally live in neighborhoods with relatively higher surface temperatures. This is largely due to past and continuing legacies of racially exclusionary urban and land use policies like redlining and the placement of freeways in Black neighborhoods. Climate change has only exacerbated extreme heat in these communities, increasing the risk of heat-related health and environmental impacts.
As we end one of the hottest summers on record across the United States, we need to consider planning and policy for extreme heat and its effects on Minnesotan communities.
The state of Minnesota and the Metropolitan Council, in conversation with local governments and other community leaders, have crafted climate policies to mitigate our carbon emissions and create a more resilient metropolitan region. We must go further to mitigate the climate risk that extreme heat poses. Even as we focus on global, national, and state-level policies to address climate change, we must also take a regional and local approach to climate resilience in the Twin Cities to protect communities from emerging climate risks.
The Minnesota Land Planning Act, a law guiding the Met Council and local governments to create long-range comprehensive plans, does not require the inclusion of climate considerations, leaving local governments to decide whether they consider climate change in their local comprehensive plans.
Out of the 160 local plans submitted to the Met Council from across the region, 57 include a chapter or section on climate resilience, and 42 integrate resilience into multiple plan elements, according to the Met Council’s roundup of comprehensive plans. This still leaves many communities not explicitly planning for climate resilience and adaptation.
We should learn from and leverage existing resources. At the regional scale, the Met Council has already created powerful tools to understand urban heat islands and tree canopies in the Twin Cities. These tools can be used to inform regional and local policy decisions and climate adaptation.
Ramsey County provides an example of incorporating climate resilience into planning practices at the county scale. Their 2040 Comprehensive Plan integrates climate adaptation and community health considerations into a conversation centering on resilience. They underscore the importance of protecting vulnerable people and call out specific strategies to mitigate extreme heat and other climate threats, such as establishing cooling centers during heat events.
Saint Paul’s 2019 Climate Action and Resilience Plan provides comprehensive maps and metrics to understand the challenges presented by climate change and centers the discussion on opportunities to create a more equitable and livable city.
In other American cities, most notably in Phoenix, the local government has established an Office of Heat Response and Mitigation. This office spearheads the effort to help residents cope with extreme heat and associated impacts for residents, as well as plan for community adaptations to make the city cooler.
Minnesota should consider infrastructure such as cooling centers, spaces where residents without air conditioning can cool off; a stronger power grid to handle increased energy demand from cooling; and more tree canopy in low-coverage areas, which can mitigate extreme urban heat.
According to a 2022 study, increasing Minneapolis’s tree coverage by 10% would save between 33 and 82 lives and generate between $270 and $680 million in annual savings.
Climate change will continue to alter the way we grapple with emerging environmental threats like the urban heat island effect. Collaboration between policymakers and local communities can ensure we implement comprehensive strategies to meet this threat and protect Minnesotans.
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