I recently had an argument with a friend who says that if we pollute and cut down the forests, it doesn’t matter because the Earth will take care of itself anyway. How would you counter such an argument?
—Alison Berglof, via e-mail
It is true that Mother Nature has amazing powers to restore her ecosystems, and most scientists agree that it would be nearly impossible for humans to destroy the Earth itself, despite our success at wreaking environmental havoc. Short of a catastrophic meteor strike or some other unforeseen galactic trauma, the Earth will likely continue to spin in the solar system, perhaps as long as there is a solar system.
Example after example from distant and recent history underscore the fact that the Earth can recover from just about any trauma—including the meteor strike 65 million years ago that many believe caused the extinction of the dinosaurs. Whether subjected to tidal waves, volcanic eruptions or nuclear bomb blasts, landscapes reform anew, even if it takes years, decades, centuries or eons.
But what is at stake if we don’t clean up our act may be life itself as we know it, both our own and that of other species with which we share the planet. We are already witnessing what may be an even larger species extinction than occurred with the dinosaurs—but this time thanks to various human activities. Eminent Harvard biologist E.O. Wilson predicts that human-caused environmental destruction will lead to the extinction of half of all species on the planet within 100 years. Such species loss is a big problem for humans. That incredible diversity of life keeps our water, soil and air healthy, our stomachs full and our ailments in check (many modern medicines originated as herbal plant remedies).
And regardless of the fate of other species, the destruction of our environment also impacts us directly. Though early conservationists sought largely to preserve nature for its own sake and beauty, most environmentalists today see a direct correlation between environmental protection and human health. Modern environmental problems like fast-paced habitat destruction, toxic chemical releases and global warming (which is exacerbated by cutting down forests) raise concerns about the spread of diseases for which we have not evolved proper defenses.
According to a 2002 Princeton University study published in the journal, Science, “Pathogens that have been restricted by seasonal temperatures can invade new areas and find new victims as the climate warms and winters grow milder.” That trend is already underway and has, so far, primarily impacted non-human animals. However, said Andrew Dobson, a co-author of the study, “The accumulation of evidence has us extremely worried. We share diseases with some of these species. The risk for humans is going up.”
“Epidemics of Rift Valley fever, a deadly mosquito-borne disease, rage through northeastern Africa during years of unusual warmth,” said the study. “If the climate becomes permanently warmer and wetter
Rift Valley fever epidemics will become frequent
Malaria and yellow fever may become more common as milder winters permit the seasonal survival of more mosquitoes, which carry these diseases. A warmer climate also could enable them to move into areas where the cold once kept them out.”