If you live in a neighborhood without dense tree canopy, you may want to celebrate Tu b’Shevat by joining with your neighbors to plant and establish a forest of tall trees around your homes. Sound like too ambitious an undertaking? It will be well worth it.
Tu b’Shevat, the Jewish New Year or Birthday of the Trees, is a day set aside centuries ago by our rabbis to remind us to take time out to appreciate and celebrate all that trees do to improve our well-being.
If you don’t feel you have enough tree blessings to appreciate, scientists in the United States and Australia have added a big one: Trees save our very lives.
It’s long been known that cities can be up to 12 degrees F hotter than surrounding tree-covered areas due to heat retention by buildings and paved surfaces — creating a phenomenon known as the urban heat-island effect. In recent years, Australian cities have experienced severe heat waves that have killed hundreds, prompting researchers to study reducing the urban heat-island effect to find out ways to protect people. Scientists from Australia’s Commonwealth Scientific and Industrial Research Organisation and Monash University in Melbourne found that in every major Australian city, deaths were highest in inner-city areas with the least tree canopy cover. They also found that the shading and evaporative cooling provided by dense tree canopy can lower temperatures by 3.5 to 5.5 degrees F — just enough to make the difference between life and death. They are developing recommendations for standards for urban tree cover to protect people.
Los Angeles and cities in the Southwest aren’t far behind Australian cities in experiencing unprecedented severe heat on an increasingly regular basis. Recent research from UCLA projects that the number of extreme-heat days with temperatures above 95 degrees F will triple in coastal and central Los Angeles, almost quadruple in the valleys, and increase by five or six times in desert and mountain areas in the coming years. The U.S. Centers for Disease Control and Prevention recently stated that extreme heat kills more Americans than all other natural disasters combined.
Trees can do a lot to help. The Los Angeles County Department of Public Health, in partnership with local organization Climate Resolve and researchers at the University of Miami, are embarking on research similar to Australia’s to look into how cooling cities with trees and other techniques can protect human lives.
For decades, students at Jewish schools and schools throughout Los Angeles County have planted seedlings with TreePeople, but now tree planting has become much more than a symbolic act. Planting the right trees in the right places, and ensuring they survive, can save people and has become urgent.
Andy Lipkis is the founder of TreePeople. For more information on how to organize tree plantings in your neighborhood, visit treepeople.org.