Google today launched a tool that could help communities keep their inhabitants cool by plotting where trees are most needed. Cities prefer to be colder than surrounding areas, as buildings and asphalt absorb sunlight. A simple way to cool off the urban areas is to grow more trees in the communities where they are scarce.
Google’s latest Tree Canopy Lab uses aerial imagery and Google’s AI to find out where every tree is in a community. Tree Canopy Lab places this information on an interactive map along with additional details on which communities are more heavily populated and more vulnerable to high temperatures. It is hoped that planting new trees in these areas would help cities adjust to the warming environment and save lives during heat waves.
Google has been piloting the Tree Canopy Lab in Los Angeles. Data on hundreds of other cities are on the way the company says. City planners interested in using the tool in the future will contact Google via a form that has been posted along with today’s announcement.
“We’re going to be able to really get home where the best strategic investment is going to be in combating the urban sun,” says Rachel Malarich, Los Angeles’ first city forest officer.
Google says that its new tool will save cities like Los Angeles time when it comes to taking stock of their trees. This is also achieved by sending people to survey each block. In the past, Los Angeles has used LIDAR technology to map their urban forest, which uses a laser sensor to detect trees—but that process was costly and slow, according to Malarich. Google’s latest app, on the other hand, is free to use and will be updated daily using photos already captured by Google Maps aircraft.
Tree Canopy Lab found that more than half of Los Angeles residents live in areas where trees shade less than 10% of their neighborhood. (The city average is over 20%, according to Malarich). It has also been found that 44% of Angelenos live in areas with extreme heat risk. Heatwaves in Los Angeles County have been becoming longer, more frequent, and more powerful over the past 50 years, according to a report published this year by NASA’s Jet Propulsion Laboratory researchers. Carries that progress forward — helping developers fund their small businesses, take risks on new ideas, expand their teams, and continue to make apps that enrich people’s lives.
Extreme heat is one of the most well-known consequences of climate change; it kills more people every year in the US than any other weather-related catastrophe. Burning temperatures can be much more harmful in cities as a result of what is known as the urban heat island effect. Urban areas with more heat-trapping areas and less greenery can be up to 6 degrees Fahrenheit hotter on average than rural areas. At night, a time that is critical for our bodies to recover from a hot day the temperature differential will rise to 22 degrees.
Trees will cool down a hot neighborhood in a variety of ways. People and buildings are shaded by the sun. And they release moisture as temperatures increase by evapotranspiration—a mechanism close to how our bodies cool down through sweating. According to the EPA, these two mechanisms will lower summer peak temperatures by up to nine degrees Fahrenheit.
Google’s Tree Canopy Lab has shown that in Los Angeles, communities with the highest heat risk tended to be more densely populated—but less densely tree-covered. Basically, areas at the highest risk of heart disease and death have fewer resources to deal with it.
Another mapping tool released yesterday that offers cities a ‘tree equity score based on their tree cover, surface temperatures, and demographic data such as the income and ethnicity of residents. This method developed by the Microsoft-supported conservation organization American Forests was piloted in Rhode Island, San Francisco Bay Area, and Maricopa County, Arizona.
Historically in the US, structural inequality has driven people of color into city hotspots. “Redlined” areas, the products of policies dating back to the 1930s that denied residents the color of home loans and insurance, are some of the hottest neighborhoods in their cities today.
The City of LA is working to green some of these neighborhoods and prepare the city for a warmer climate. By 2028, the city aims to raise its tree canopy coverage by 50 percent in “low-income, extremely heat-affected” communities. It also set the target of planting 90,000 trees in the city by 2021. This is projected to offer an additional 61 million square feet of shade to the area.