When Joe Caesar was growing up, his mother led cleanup projects in their North Philadelphia neighbor- hood in Philadelphia. She often brought Joe along. He’d pick up trash and plant trees and flowers, he says.

Those early experiences set him on a career path to work in parks and environmental education. For the past 10 years, he has been the senior community initiative specialist and manages the TreeKeepers program in Philadelphia. The city program hires teens and young adults to plant and prune trees, remove vines, and take care of natural areas. They also give free trees to city residents at dozens of neighborhood events every year.

Trees have so many benefits, says Mr. Joe, as he likes to be called.

Cleaning up and beautifying a neighborhood encourages people to put their trash in a can instead of throwing it on the ground, he says. It also can help cut down on crime. A recent scientific study even shows that there is a link between more trees in a neighborhood and less firearm violence, according to an article on the University of Pennsylvania website.

Trees have other benefits, Mr. Joe says. They provide oxygen and help clean the air. “If we don’t have trees, we will have bad air and it will be hard to breathe,” he says.

Because trees are so important, Philadelphia government officials have adopted a 10-year plan to increase the city’s tree canopy. A tree canopy consists of the branches and leaves that cover the land.

Philadelphia wants to plant enough trees for the canopy to cover 30 percent of the city, according to the Philly Tree Plan: Growing Our Urban Forest. Just 20 percent of the city has a tree canopy now. But some places have a lot more trees than others.

The Philly Tree Plan shows a number of reasons the city needs more trees. The plan says trees help:

• Offer protection from heat
• Improve mental health and wellness
• Prevent flooding

Mr. Joe says the city wants to plant thousands of trees over the next five years in Philadelphia. He encourages kids to see whether a tree might be right for their neighborhood and seek other ways to beautify their environment.

Mr. Joe tells us that we can make a difference in our neighborhood as he did with his mother—maybe even plant a tree.

“I want you to start thinking about problem-solving in your environment,” he says. And about what you can do to be the change agent.