Extreme Heat
Global Warming Impacts
Global warming is one of climate change’s main impacts. Since 1880, the global temperature has increased by 2°F, with the rate of warming doubling in the past 40 years. Not only do warming air and ocean temperatures alter ecosystems and fuel more intense storms, but they also create dangerous conditions for the most vulnerable communities. Climate change will make extreme heat days (90°F+) 3-5 times more likely in North Shore communities.
“The 10 warmest years in the historical record have all occurred since 2010.”
Urban Heat Island Effect
Cities often experience hotter temperatures compared to rural or suburban areas, sometimes as much as 7°F higher. This phenomenon is called the Urban Heat Island Effect and can exacerbate the impacts of extreme heat events. The Urban Heat Island Effect has several underlying causes:
- City buildings and streets are often constructed with dark, heat-trapping materials, such as asphalt, concrete, and brick. These materials absorb heat and release it back into the environment.
- Tall buildings can alter air flow, preventing wind from dissipating hot air and cooling parts of the city.
- Waste heat from vehicles, air-conditioners, and factories emit additional heat into the urban environment.
- Plants naturally release water from their leaves through transpiration and provide shade. Since cities often have fewer green spaces, they lack the natural air conditioner that plants provide.
With its limited tree canopy and dark, paved surfaces, we see the impacts of the Urban Heat Island Effect in the highly urbanized areas of Downtown Salem and The Point. Salem Common stands as a cool oasis with its abundance of green space and lush tree canopy.
“Extreme heat events have claimed more lives in the United States over the past 10 years than any other weather-related event.”
Threats to Humans
The combined effects of climate change and extreme heat often impact the most vulnerable people in our communities. This creates an equity and environmental justice issue, as it disproportionately impacts certain socioeconomic groups. During extreme heat events, we see an increase in hospitalizations and deaths from chronic illnesses that have been worsened by heat exposure. Poor air quality associated with an increase in ozone, particulate matter, and pollen during extreme heat events triggers pre-existing conditions such as asthma and allergies.
“Across U.S. cities, people of color are exposed to on average 1°C higher urban heat than their white counterparts.” –
