Urban heat islands also affect our ability to breathe. Hot, humid air traps pollution and ozone, which trigger asthma attacks—the number one cause of emergency room visits in low-income areas. The people most at risk are the most vulnerable: the very young, the very old and the very poor.
Urban heat islands affect low-income populations disproportionately due to poor housing conditions—lack of air conditioning, small living spaces, limited resources. But there is hope: Nature can help alleviate the effects of urban heat islands and make our cities even more livable.
Trees and other vegetation go a long way to improving the quality of life in cities, and helping to reduce the threats of urban heat islands. They provide shade, which has been shown to lower surface temperatures by up to 45 degrees, and they cool the air by using heat to evaporate water.
Well-designed green spaces in cities can absorb carbon, thus helping reduce the cause of climate-change, filter asthma-inducing pollutants from the air, capture stormwater runoff to help improve water quality, and provide important habitat for birds, butterflies and other urban wildlife.
In New York City, we are working with City officials to address the problem at a local level. The City has programs in place to plant trees, improve natural infrastructure, and invest in our parks and natural areas.
As more and more people move into cities, we need more investment in these solutions that benefit both nature and people—especially those who are most vulnerable. Imagine cities around the world transforming from concrete ovens to shady refuges, and our planet’s most at-risk urban centers turning into havens for people and nature.
Urban heat islands are a very real, very threatening problem indeed, and nature is a very real solution.
This fall, the Conservancy will announce the findings of an exciting research project that will quantify the value of trees in reducing neighborhood air temperatures in more than 200 cities around the world. The Planting Healthy Air study will be an important resource for city planners who seek to use the power of nature to make their cities more livable.
But in the meantime, leadership like Bill’s in New York, and our colleague Laura Huffman’s in Texas, is critical as we adjust to the new normal of a warmer world.
Bill Ulfelder is the Executive Director of The Nature Conservancy in New York. Pascal Mittermaier is the Global Managing Director for Global Cities at The Nature Conservancy.