Trees … To Be or Not to Be

By David L. Brown

The growing concern about “global warming,” that misleading terminology used to define the climate change that is taking place on the Earth, has yielded a number of proposals to help mitigate the rise of greenhouse gases (GHG) in the atmosphere that lie at the root of the problem. Many of these ideas revolve around the role of trees in our climate.

For example, it has become the “in thing” for the wealthy to plant trees to “offset” the carbon their activities release into the air. A rock and roll band recently did just that to offset the GHG released by the production and distribution of their latest album. Others have followed suit, “offsetting” their jet-setting lifestyles. These individuals believe that their tree planting efforts make them appear “green” as they continue their profligate lifestyles.

There are, however, some problems with this. First, even if the entire presently unforested areas of the planet’s surface were to be converted to an endless expanse of trees, it would not be able to compensate for the present rate of human produced carbon entering the air.

And, not all areas are suitable for arboriculture (tree farming). Imagine the results when some rock star attempts to plant a thousand hectares of trees in the middle of the Sahara Desert to offset the energy used by his private jet and you will see my point.

Then there is the all-important question of what impact planting all those trees would have on agriculture, that rather necessary activity that stands between humanity and mass starvation. Many of the same areas that might be converted to forests are needed to grow crops of another kind, for food. We humans are not like beavers or termites that can survive by munching on wood. Even the planet’s wide grasslands are needed to sustain wildlife and herds.

Now researchers at Lawrence Livermore National Laboratory in Berkeley, California have come up with a new climate model that contradicts the idea that trees are a good thing for atmospheric GHG.

According to Govindasamy Bala, who with his colleagues developed a computer program called the Integrated Carbon and Climate Model, removing all of the world’s trees might actually cool the planet. His reasoning: Forests, especially of the evergreen variety that are found in temperate zones, are dark-colored and absorb heat. Even in winter, their dark needles cause a forest to appear as a dark, light-absorbing area. Open land, on the other hand, is lighter, particularly when covered with snow, and will reflect more of the Sun’s radiation back into space thus resulting in a cooler planet.

This utterly ignores the fact that in tropical regions there is seldom any snow to reflect the heat of the Sun — not to mention that the process of deforestation could turn vast regions into desert. Especially in the tropics, when rainforest is cut down the soil quickly turns to a hardpan that is unsuitable for crops. That is the sad story in the Amazon Basin, where farmers clear land, grow soybeans or other crops for a few years, then leave the farmed-out and sterile soil behind and cut some more trees.

Returning to the above-mentioned Sahara Desert, ask yourself whether the lack of trees can be equated to cooler temperatures? Well, OK, that’s not a scientific observation, but it does raise an interesting point. And, in fact, Dr. Bala admits that in tropical regions cutting down forests would result in both regional and global warming — his ideas only work in the higher latitudes where most people live and where agriculture is at its most productive.

Here’s another point: In prehistoric times far more of the planet’s surface was covered with forests, including most of Europe and much of North America as well as the vast and now shrinking rainforests circling the Equator. If trees are such a bad influence on the planet’s temperature, as Dr. Bala proposes, one would guess that in those days the thermostat would have been set even higher than today … and yet it is only since human-produced GHG began to be introduced into the atmosphere that the warming has begun to rise appreciably.

And here is another viewpoint on this question, one related to transpiration. This is the process by which plants draw moisture from the soil, utilize it for growth, and finally evaporate it into the air. Forests are among the largest contributors to transpiration, and the end result is more moisture in the air. Moist air means clouds, and clouds reflect solar rays back into space, thus helping to cool the planet.

So, which is it? Do trees make the Earth warmer, or cooler? Well, perhaps they do both and in many other ways contribute to the balance the Earth needs to sustain the many lifeforms which call it home.

All of this reminds me of the splendid book “The Coevolution of Climate and Life,” published more than 20 years ago. In its pages, this substantial work by leading atmospheric scientist Stephen H. Schneider explores the ways in which the climate of our planet may have “evolved” over billions of years in response to the growing complexity of plant and animal life. The result is the intricate web of effects that makes the Earth “work.”

The Gaia theory set forth by James Lovelock also comes to mind (see my book review of Lovelock’s latest book, “The Revenge of Gaia,” posted here July 23, 2006.) Lovelock makes the analogy that the Earth is a living organism in itself, one that has been sorely wounded by human activity.

As it seems to me, the trouble with ideas for mitigating climate change by altering our natural landscapes are not only questionable, but very likely dangerous. After all, many if not most of our environmental troubles are due to human meddling with the natural processes of the Earth.If we as a species had shown ourselves to be smart enough and wise enough to change our planet without sowing the seeds of disaster, that would be one thing. But our track record on this is rather poor (note: understatement) and who is to say that any further attempts at planet modification might not lead to even more disaster?

The search for easy answers, ones that do not require sacrifice and changes in lifestyle for people used to an energy-intensive civilization, should be looked upon with suspicion. Cutting down all the trees would almost certainly inflict another vicious wound in the already sorely injured “body” of Gaia, perhaps a fatal one. Sadly, it is far easier for we humans to accept the possibility of “easy answers” than to embrace the economic and lifestyle changes that could make a more direct impact on climate change by reducing our use of fossil fuels.

The natural processes of the Earth are enormously complex and involve interwoven connections that we cannot hope to fully understand. Hubris, that most tragic form of pride and arrogance, has led us to where we stand today, on the brink of climate change that could prove disastrous to our very existence.

Hubris was the affliction or character flaw that brought down the subjects of Greek tragedy, and it is no less a problem today. McGeorge Bundy, one of John F. Kennedy’s advisors on national security, recognized the danger of human arrogance when he said “There is no safety in unlimited technological hubris.” That applies today more than ever, and particularly in the area of climate change.

The way to go is backward, not forward. We must work toward restoring the natural processes of the planet, not to change them even more. We need to help Gaia to heal and regain Her balance. To do otherwise is to play the role of a demented and misguided Dr. Frankenstein by attempting to create from our stricken planet an unnatural and unsustainable “creature” that bears no resemblance to the beautiful and awe-inspiring condition that came about through natural forces.

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