On Friday, the city cut down the healthy 50 year old ash tree outside my bedroom window. The reasons cited: streetlight and minor pavement damage. I’m no Julia Butterfly Hill, but when the notice first went up, I complained to the proper authorities, who assured me that the site would be re-evaluated. That was the last I heard when the men with the saws came. For six hours, the roar of the chainsaw ground through my bones. All day, I felt cold, queasy, and thoroughly ashamed at my species. What kind of society values a streetlight and concrete over a beautiful, mature, living tree?
Part of it was the timing. I’m currently reading The Man Who Planted Trees by Jim Robbins, which is about David Milarch‘s quest to preserve and clone the trees most likely to survive in an inhospitable future. I had just read this stunning figure: as of 2010, about 8 million acres of lodgepole and ponderosa pine in the US and 43 million acres in Canada have been killed by bark beetles. I can’t even imagine what 51 million acres looks like. Milder temperatures caused by climate change have extended the destructive beetles’ season from two weeks to six months, broadened their range, and increased their victims from mature trees only to saplings. There’s even some evidence that pine beetles are starting to attack other tree species. And warmer weather often means dryer conditions, which stress already vulnerable trees. The bottom line? 6.3 measly degrees is going to make a huge difference for trees. How much, we don’t really know — there’s an overwhelming lack of information when it comes to tree research.
Even if we stopped logging right now (78% of our ancient forests around the world have already been cut down), our trees would still be in trouble from climate change. As the author says, “The only thing harder on trees than beetles, it seems, is people.” Ouch.
If you consider yourself a tree person or even someone moderately invested in the future of humanity and this planet, you should be deeply concerned about a future with fewer or no trees. Trees matter. I’ve come up with an idiosyncratic and incomplete list of why. (Many are taken from Robbins’s book, which I recommend.)
- Trees have a net cooling effect in city as well as forest settings. According to the USDA, “the net cooling effect of a young, healthy tree is equivalent to ten room-sized air conditioners operating 20 hours a day.” Unfortunately, warmer conditions under climate change kill trees, and losing trees leads to warmer conditions, and there you have it — a positive feedback loop and a perfect recipe for climate destabilization.
- Massive flooding in Thailand, China, and Pakistan has been partially linked to deforestation. Trees ameliorate flooding, absorbing and slowing waterflow, protecting river banks against erosion and run-off, and replenishing water tables. Clear cutting these natural barriers aggravates flooding.
- Many trees are considered keystone or umbrella species that an ecosystem would collapse without. Protecting, say my beautiful coast redwoods, protects a vast array of animals and plants that redwoods support.
- Trees absorb carbon dioxide and produce oxygen. Duh. According to the USDA and the Arbor Day Foundation, “an acre of forest absorbs 6 tons of carbon dioxide and puts out four tons of oxygen. This is enough to meet the annual needs of 18 people.” I wonder what our current forest / human ratio is?
- Trees can lower energy bills. Plant them strategically to produce shade and reduce wind. According to Dr. McPherson of the Center for Urban Research, planting one tree on the west side of your house will yield about 12% energy savings in 15 years. (Yes, it takes a while. But as the saying goes, the best time to plant a tree was 20 years ago. The second best time is now.)
- Trees scrub our world clean of toxic substances. They can clean up toxic waste better and cheaper than conventional cleanup. It’s called phytoremediation. The roots absorb and break down substances like ammonium, nitrogen, pesticides, and nitrogen run-off from farms that cause dead zones. They can even deal with things conventional methods can’t extract, like pharmaceuticals and endocrine disruptors. One willow can process 15 gallons of waste a day.
- Seeing trees makes humans less crazy. Going for a walk in the woods helps kids with ADD concentrate and increases anti-cancer proteins in cells. Proximity to green space reduces the rate of anxiety disorders. Even having a home view of trees cuts down on aggressive conflicts with family members. How do they do it? One theory is that tree gives off a chemical cocktail as an aerosol.
- Civilizations that cut down all their trees collapse. This is Jared Diamond’s theory, not mine, but he provides so much proof in Collapse that it’s hard to disagree with his central thesis that misusing our natural resources predictably comes around to bite us in the ass. Money is not edible. To paraphrase Diamond, “being rich just means being the last to starve.”
Trees plainly deserve more attention in the green conversation than they’ve been getting — more research money and energy, too. When I read my Twitter feed and come across yet more articles on miniscule impacts to human health (chemical x is linked to cancer / asthma / infertility / whatever human ailment), I just want to shout, “Hey! Other species besides humans matter!” And then I grumble in my head about why we’re wasting so much energy and money investigating infertility when, at 7 billion people + and rising, infertility is clearly not a major problem humans are facing. But I digress.
While writing this entry, I’ve decided that my next move is to harangue the city arborist again. If the city budget won’t stretch to replace my cherished street tree, I’ll pay for it myself. It’ll be worth it, emotionally as well as ecologically.
When’s the last time you thought about trees? Did I miss anything major on my list of why we should give a damn about them? (Maybe just the fact that they’re beautiful and fascinating and we don’t really know that much about them?)
Photo credit: Redwood Canopy by Tolomea