“What kind of times are they, when a talk about trees is almost a crime because it implies silence about so many horrors?” (Bertolt Brecht)
Global warming, desertification, soil erosion, water pollution, species extinction and resource depletion are all environmental issues we face in the 21st century. Though the causes and cures of these environmental maladies are numerous and complex, there is at least one common thread that serves as the warp for the weave of this sickness killing our planet: deforestation.
Clive Ponting, author of A New Green History of the World, tells of the Easter Islanders who, although they were in a perfect position to predict and control their fate, willfully depleted their arboreal resources nearly to the point of their own extinction (1-7). Although this example shows the direct relationship between man and forest, and how the depletion of one can lead to the extinction of another, the effects of deforestation are not always as transparent.
Possibly the most significant environmental issue threatening our existence today is that of global warming. Most would agree that the primary cause of such warming is the CO2 emissions generated through the burning of fossil fuels. However, less obvious is the role that deforestation likely plays in the speed of this warming. According to Mark Hertsgaard, author of Earth Odyssey, “… deforestation also boosted global warming because it released additional greenhouse gasses into the atmosphere even as it deprived the planet of millions of trees that, through photosynthesis, could absorb excess carbon dioxide” (11).
In addition to the acceleration of the greenhouse effect by the cutting down of trees, deforestation takes on many other shapes and forms. What happens to the land, for instance, once the trees are downed to provide firewood, crop land or pastures? Ask the people of Sudan, and they will likely answer: soil erosion and desertification. Through the process of transpiration, trees return moisture to the air, and that moisture, in turn, plays its role in the water cycle and results in higher humidity and rainfall. For example, during the growing season, an average-sized birch tree can transpire as much as 3,700 liters of water a day (Mader 469). Imagine then, the impact of clear-cutting a forest in a region already prone to high temperatures and drought. Add to that the effects of soil erosion, caused by the loss of protection and support provided by tree canopies and root systems, and you have effectively created a new desert. According to Ponting, “The best estimate is that the world’s deserts are expanding by about 70,000 square kilometers a year” (257).
Once lost, soil cannot quickly be replaced. In fact, it takes thousands of years, through an intricate combination of physical, chemical and biological processes to produce even the smallest amount of soil from rock, decaying organic matter, rainfall and heat. It is for this reason that soil is considered to be a non-renewable resource (Ponting 14). What happens then, when we cut down our trees and create new desert, is that we forever sentence that land to death. With few exceptions, it can no longer naturally support life – neither animal nor vegetable.
While soil erosion caused by deforestation results in the inability to support life in the most arid parts of the world, it wreaks havoc in an entirely different way in some of our mountainous regions: debris flows. Debris flows are the result of a process that often begins with forest loss through fire, which is a natural phenomenon. For centuries, forests have burned and life has been renewed through natural processes involving the germination of seeds through heat and the returning of nutrients to the soil. However, human intervention via unsuccessful attempts to prevent such fires has resulted in conflagrations that burn hotter and faster than those that occur naturally. The result is a barren hillside, that when besieged with heavy rains, transforms the rock and mud and burned remnants from the fire into a wall of energy causing erosion like nothing else. John McPhee, author of The Control of Nature, said this of the power and enormity of a debris flow in Los Angeles, “The dark material …was not only full of boulders; it was so full of automobiles it was like bread dough mixed with raisins” (185).
Just like erosion caused by tree loss can be devastating to our land, it can be equally as destructive to our water quality. The root systems of trees act like safety nets along our shorelines, keeping valuable soil from washing into our waterways and polluting them with excessive sediment and debris. Trees provide buffer vegetation also capable of absorbing nitrogen and phosphorus from agricultural runoff that can lead to eutrophication, causing algae blooms that deplete the oxygen content of our water. The leafy canopies of trees can prevent thermal pollution of our waterways, by shading the ground adjacent to and the water itself. According to the Clean Water Campaign website, “Maximum summer temperatures in a deforested stream may be 10-20 degrees warmer than in a forested stream” (“Planting Trees…”).
Finally, any comprehensive discussion of today’s environmental concerns would not be complete without at least a mention of species extinction. Habitat loss is perhaps the biggest threat to wildlife today, and this is why individual forested ecosystems, like the mangroves discussed by Vandana Shiva in Stolen Harvest, are so incredibly important to the survival of life (45-46). Indonesia, which has the largest area of mangroves in the world, has already lost more than 45% of its mangrove habitat, and according to Sylvia Mader, author of Biology, “… the percentage is even higher for other tropical countries” ( 934). According to Hertsgaard, tropical rainforests are home to more than half the world’s organisms (11). Ponting reminds us that when we clear these rainforests, we are not only ridding the land of trees, we are wiping out entire ecosystems. “The actual rate of species loss is unknown, but the best estimate would suggest about 50,000 a year, most of whom were unknown to science when they became extinct” (252). The loss of even one species could prove to be detrimental in the long run, due to the intricate balance between one species and another, and the chain of events that occurs when the food chain is interrupted. But 50,000 a year is almost beyond comprehension.
In the preceding paragraphs we have explored how many of the world’s most critical and time-sensitive environmental problems could at least be partially resolved by reforesting our Earth. Why don’t we, then? Certainly there are mavericks here and there who are attempting to do just that. In Terry Williams’ “The Wild Card,” she speaks of a Kenyan woman who founded a tree-planting project in her country called the Green Belt Movement. Over a period of sixteen years, more than a million children participated, resulting in the reforesting of more than ten million trees (136-137). In Gaviotas, Alan Weisman tells the story of how the people of the llanos created an entirely new forest, planting hundreds of thousands of hectares with Caribbean pines – a project so successful that it drew attention from around the globe (161-222). But solving this issue is going to take more than planting a few million trees. In order to adequately address the fallout of deforestation, we not only need to plant more trees on a magnificent, global scale, we first need to stop the current and continued act of deforesting. The United Nations estimates that tropical rainforests are being cut at the rate of 15,000 square miles a year. In the United States, only about ten percent of old-growth forests remain, and they are being logged at a rate of 60,000 acres a year (Getis, Getis, and Fellmann 166-167).
“What kind of times are they when a talk about trees is almost a crime because it implies silence about so many horrors?” (Bertolt Brecht) They’re the times of change; of rebellion; of anarchy if need be. We have to stop the silencing of those horrors, and instead shout them from the rooftops. We must take back our forests if we ever hope to save our Earth.
Getis, Arthur, Judith Getis, and Jerome D. Fellmann. Introduction to Geography. 11th ed. New York: McGraw-Hill Companies, Inc., 2008.
Hertsgaard, Mark. Earth Odyssey. New York: Broadway Books, 1988.
Mader, Sylvia S. Biology. 9th ed. New York: McGraw-Hill Companies, Inc., 2007.
McPhee, John. The Control of Nature. New York: The Noonday Press, 1990.
“Planting Trees to Protect Streams.” Clean Water Campaign. 3 Oct. 2008 http://www.wateryear2003.org/en/ev.php-URL ID=5137&URL DO=DO TOPIC&URL SECTION=201.html>.
Ponting, Clive. A New Green History of the World. New York: Penguin Group, 2007.
Shiva, Vandana. Stolen Harvest. Cambridge: South End Press, 2000.
Weisman, Alan. Gaviotas. White River Junction: Chelsea Green Publishing Company, 1999.
Williams, Terry T., An Unspoken Hunger. New York: Vintage Books, 1995.