How Trees Can Help Cool Urban Heat Islands

How Trees Can Help Cool Urban Heat Islands Nowhere is this heat felt more than in cities. Heat is amplified in “urban heat islands” where roads, pavement and buildings absorb and retain heat, and then release it back into the air, well into the night. Some urban neighborhoods can have mid-afternoon temperatures that are 15°F to 20°F hotter than nearby tree-lined communities or rural areas. Trees can save lives Planting trees is one of the most effective strategies to protect people from heat in cities, especially in low-income neighborhoods that have fewer shade trees and higher temperatures than wealthier neighborhoods with tree-lined streets. Trees can lower the air temperature in city neighborhoods by 10 degrees. The less the pavement is exposed to the sun, the less it will absorb its energy. Trees not only provide shade, their leaves release moisture to cool the environment. This reduces the demand for air conditioning, helping to avoid power failures during heat waves. Cooling is not the only benefit that trees bring to urban environments. They also reduce air pollution, absorb storm water, store carbon, attract wildlife and improve our mental and physical health. https://poweroverenergy.org/how-trees-can-help-cool-urban-heat-islands/ https://www.epa.gov/heatislands/using-trees-and-vegetation-reduce-heat-islands https://treecanada.ca/blog/how-trees-keep-us-and-our-communities-cool/ Herschel Walker’s anti-tree campaign is genius? https://www.washingtonpost.com/.../herschel-walker-anti.../ Herschel Walker Bashes New Climate Law: ‘Don’t We Have Enough Trees?’ https://www.rollingstone.com/politics/politics-news/herschel-walker-bashes-climate-law-trees-1234579587/ With extreme heat waves in Europe, Asia, the United States and beyond, it’s clear climate change is making summers more dangerous and deadly. Urban areas are feeling the worst effects; a phenomenon known as the urban heat island effect. 2022 saw high temperatures in Kansas, Spain, Portugal, England (especially London), and India. But even within cities, the warming is not distributed evenly. During the Pacific Northwest heat dome of 2021, the region's most extreme heat wave ever, this temperature difference reached a staggering 25°F between neighborhoods in Portland, OR. And new research is illuminating how a century of racist housing policies known as redlining have contributed to this often deadly inequality. The 2022 heat waves are not single events. They are another data point during years of escalating extreme weather. Previously, the 2019 European heat wave, the 1980 US heat wave, 1995 Chicago heat wave and many more are part of this trend. In this episode we are going to dive into this unjust history of housing discrimination and see what it can teach us about how to keep cities cooler and save lives. We’ll visit Richmond, Virginia and Portland, Oregon to understand the problem and solutions. Innovative solutions are being carried out at the Science Museum of Virginia and by the Portland organization, Friends of Trees. Weathered is a show hosted by weather expert Maiya May and produced by Balance Media that helps explain the most common natural disasters, what causes them, how they’re changing, and what we can do to prepare. https://youtu.be/pkTpfLqtSpQ https://www.nationalgeographic.com/environment/article/heat-related-deaths-attributed-to-climate-change Mixed landscapes are the best way to adapt to climate change and mitigate the heat island effect in semi-arid regions https://www.sciencedaily.com/releases/2020/10/201013175028.htm Why greener cities are cooler. Cities with more green spaces can stay cooler in hot weather and provide fairer lives for their residents, experts say. Clear evidence links the state of equality in cities to tree cover, says the World Resources Institute (WRI), a global research organization focused on protecting Earth's environment. This suggests that trees do much more than keep cities cool. Trees, shrubs, grass and other greenery helps keep cities cooler and more equal, research shows. Planting green areas can be costly, meaning they’re sometimes found mostly in the wealthier parts of cities, says the World Resources Institute. In the UK, minority ethnic groups are four times more likely than white people to live in neighbourhoods most vulnerable to extreme heat, according to a new study. Biodiversity schemes and innovations such as rainwater capture are being launched in cities around the world to help redress this imbalance. https://www.rewildingmag.com/green-space-cool-cities-heat-waves/ https://www.weforum.org/agenda/2022/08/green-cities-are-cooler-and-fairer/ The effect of tree shade and grass on surface and globe temperatures in an urban area SURFACE TEMPERATURES As expected, concrete and asphalt surfaces in the sun heated up much more than grass surfaces in all four experiments. In the small experimental plots the concrete in full sun rose to peak temperatures on hot days some 19–23 °C higher than air temperature, whereas grass in full sun had peak temperatures 0–3 °C cooler than air temperature (Fig. 3a–c). This meant that grass plots were around 24 °C cooler than concrete. In the park, concrete and asphalt surfaces were some 18 °C warmer than local air. https://www.sciencedirect.com/science/article/abs/pii/S1618866712000611 Trees cool the land surface temperature of cities by up to 12°C An analysis of satellite data from 293 cities in Europe has found that trees have a big cooling effect while other green spaces don't. https://www.newscientist.com/article/2298675-trees-cool-the-land-surface-temperature-of-cities-by-up-to-12c/ In Canada: Heat waves are increasing, and some neighbourhoods will be worse off https://www.theweathernetwork.com/ca/news/article/is-toronto-ready-for-worsening-heat-waves BONUS STORY: Want to Solve Wildfires and Drought? Leave it to BEAVERS! https://youtu.be/6lT5W32xRN4