Cities are losing more than 36 million trees each year. This is one of the biggest risks to our environment that the National Park Service (NPS) sees. In a piece on NPR today, William Mandia, the NPS’ Acting Director for National Parks, says that if cities continue to lose trees at the rate they are losing them, by 2085 half of all trees will have been lost.
Trees reduce the temperature of our cities, they keep parks clean and the trees we currently have “wept over” millions of years for the promise of our future,” says Mandia. “That’s a promise we should keep.”
Now, cities aren’t alone when it comes to losing trees. During the severe drought and freezes that hit California last winter, everyone suffers, from farmers to cities. Here are some studies on why losing trees is important.
The loss of trees raises temperatures in our cities. A loss of 22 trees brings in about an additional 10 degrees Celsius (33.5 degrees Fahrenheit) of warming and a loss of 30-50 trees brings about an additional 10 degrees Celsius (33.5 degrees Fahrenheit).
Trees shade the ground below. The climate research department at Columbia University found that people in urban areas tend to be 65% more likely to be exposed to poorer health as a result of an increase in heat during summer months.
Trees absorb carbon dioxide. Since these trees capture and store carbon dioxide (CO2), reducing the CO2 on land contributes to the climate change effects.
Trees filter pollution. Trees also absorb toxic chemicals and other pollutants that come off vehicles and oil refineries in and around our cities.
Trees block excess heat. An arborist at Oregon State University says that losing trees results in more radiant heat on the ground.
Trees serve as a natural fire retardant. As we plant more natural forest, tree fires give off so much carbon dioxide that it makes natural forest more effective in mitigating the effects of a fire.
Trees serve as a source of nutrition for communities. Growing up without trees can lead to childhood asthma. The EPA says that 46% of all asthma patients had asthma that was linked to air pollution.
Connecting the dots
Last year Mayor Bowser of Seattle celebrated the 5th annual Arbor Day. He also included a survey in the proclamation to give residents a better sense of what to do during Arbor Day.
Check out the survey below. It explains which trees are in the city and how much you should plan to plant (and when), how to plant them and get an education about trees.
What you need to know