The leaves of trees, like all plant life, engage in photosynthesis, which swallows CO2 as a raw ingredient to produce sugar the plant needs for survival. So in addition to urging our factories to cut back on carbon emissions, why not plant trees to scrub away the CO2?

Yet here on Maui, instead of growing healthy crowns that expunge CO2, we seem to promote the opposite: leaves are whittled away to nothing, as crowns of so many trees are hacked into round shapes mimicking lollipops and pompoms. Just because you see this abuse everywhere doesn’t make it right. The fact is: When a branch is cut off midway (instead of properly cut at its intersection with another branch or trunk), the tree never grows back another branch. Instead what you get are sprouts – weak, scraggly, messy, ugly, dangerous and deadly sprouts.

* Sprouts are weakly attached to a tree, and hence hazardous. Their litter falls off easily and hits the ground, and maybe even you.

* Sprouts crowd out each other. When you hack off a treetop, so go the leaves needed for photosynthesis. Facing starvation, the tree breeds many squiggly sprouts as fast as it can. Where once there was one branch, now there are too many sprouts competing to reach the sun. The weakest ones die off, bequeathing dead branches that suck energy from the tree and in time litter the ground – or kill the tree.

* Tree-topping is expensive, because to maintain the tree’s refined lollipop shape, you’ll need to pay your hacker to come back and redo the job, over and over again. When an arborist properly prunes a tree by such correct practices as opening up and thinning out, there are fewer leaves to litter the ground. The tree costs less to maintain; it is safer, healthier, raises property values, looks beautiful, releases a fresh breath of oxygen; and sweeps the air of CO2.

We all know temperatures are cooler in the shade. But did you know the sunlit area beyond the shade is cooler too? Maui County’s parking lot requirement with one tree for every five stalls not only cools the shaded stall, but also cools the ambient areas outside the shade due to less reflective heat. Intermittent trees create mottled shade that cools our entire neighborhood. As a bonus, numerous studies report how shoppers spend more money in malls with invitingly cool and shady parking lots.

What’s more, research has shown that tree-shaded buildings save dollars wasted on air-conditioning costs. Even shading the walkways to your entrance will reduce AC costs, instead of your overheated body cooking up the room.

For more information, don’t miss the Lawn and Garden Fair at the Maui Mall on June 18. The International Society of Arboriculture has many instructive online teachings and booklets on its Trees are Good website (treesaregood.com). “Stop the Chop” is the informal motto of Maui Green and Beautiful (mauibeautiful.org), which organizes the annual Malama the Trees conference during Arbor Week in November. Attend classes and workshops from University of Hawaii Maui College EdVenture and Earth Day events. And, hire an arborist to cut trees wisely.

In my opinion, our world could stave off global warming – or at least Maui warming – if everyone would plant trees, and if no one would hack the ones we have.

* Jean A. Pezzoli, Ph.D., is a professor and institutional researcher at University of Hawaii Maui College. She is also a UH-MC EdVenture tree-care instructor; two-term Maui County Arborist Committee member; and past president of Maui Outdoor Circle.