Truly “green” trees

I lost a magnificent shade tree in front of my house during the big storm a few weeks ago. Now I’m charged with finding a replacement tree. Are there any choices you can suggest that might be “greener” than others?

Some people call trees “carbon sinks.” I like to think of them as baby sitters, photosynthesizing the mess of carbon dioxide that mankind has spilled into the atmosphere with childish recklessness.

What is photosynthesis, you ask? It’s the process by which trees absorb and store CO2, the greenhouse gas that cars and other man-made operations pump into the atmosphere. Trees then produce oxygen, a crucial element in that collective suburban sigh of relief after a long gas-guzzling freeway commute that, once again, didn’t result in a much-deserved public scolding.

All trees absorb and store CO2, but there are certain characteristics that elevate some trees above others. More biomass equals more absorption, so in short, look for a tree that grows fast, grows big and is resilient in the local climate.

A 2002 study co-authored by Dave Nowak, a researcher at the U.S. Forest Service’s Northeastern Research Station in Syracuse, New York, recommends the common horse-chestnut, black walnut, American sweetgum, white pine, London plane, Douglas fir, scarlet oak, red oak, Virginia live oak and bald cypress, among others, as examples of trees that are great at absorbing and storing CO2. Of course, this particular study was intended to address “carbon sequestration,” or maintaining forests specifically for long-term carbon storage. Sounds good at first glance. But my social circle is hesitant to endorse this band-aid on a real wound: namely that humans are irresponsibly producing massive amounts of CO2 in the first place.