Researchers in Antarctica have been keeping watch on the infamous ozone hole over that continent for several decades. The Montreal Protocol on Substances that Deplete the Ozone Layer was a multinational agreement signed in 1987 designed to reduce the production and consumption of ozone depleting substances that enter the atmosphere. It has been amended in various ways on many occasions over the subsequent years.
Why should you care whether there are trees on your street or on the streets nearby? Besides the obvious fact that they make streets more attractive, street trees provide a number of real benefits both for residents and for the environment.
Globally, air pollution kills 3.3 million people per year. And this number could double to 6.6 million people by 2050 if little is done to decrease the dangerous levels of tiny particles, toxins, and ozone in the air.