With the arrival of April, we welcome Earth Day, a time to consider our obligation to the environment. Earth Day is an appropriate time for Americans to consider their record as keepers of our nation’s lands and waters, a country blessed with bountiful natural resources.
This is also election season, and candidates like Rick Santorum are suggesting that President Barack Obama’s worldview placed care of the earth and natural resources above human needs. “The earth is not the objective,” he said on CBS’s “Face the Nation.” “Man is the objective, and I think that a lot of radical environmentalists have it upside down.” This view is echoed by others in public life who suggest that mere humans do not affect the large forces that control the earth’s environment.
Long before humans appeared, they note, the earth’s overall temperature varied through the ages from tropical to very cold. Atmospheric green house gases, like carbon dioxide, were often at several times the levels of today without us. More recent temperature variations, like the medieval warm period when the Vikings colonized Greenland, and the following Little Ice Age, occurred before the Industrial Revolution and substantial human, greenhouse gas emissions.
Canadian scholar Vaclav Smil has quantified the difference of the energy used by the average human through history. Muscles aided by simple tools were the prime movers for all of human existence until the early modern era. The farmer working his field could maintain output at the equivalent of 70-80 watts. A big advance was the taming of large animals, and behind a pair of properly yoked draft horses he controlled at least 800 watts. Now, his great-grandson controls tractors and combines with the power of a 100,000 watts.
As William Catton put it in his pioneering work, “Overshoot,” we are now homo colossus, each of us having the energy impact of the hundreds of slaves once controlled only by lords and kings. Fishermen once cast a few lines or nets, which they could manage. Today, they are in large trawlers whose powerful diesel engines control miles of nets with the ability to eliminate whole species from the oceans.
As we look east, we see Appalachian mountain forests clear cut so our tractors can push mountain tops off into the valleys, retrieving small seams of coal while blocking miles of streams in the ruined valleys below. In the Midwest, our machines allowed us to plow vast dry area grasslands, which once supported countless birds and buffalo. Now, we grow crops intended by nature for wetter regions. To accomplish this, we pump up three feet of irrigation water annually from underground aquifers, which are replenished by nature at the rate of one inch per year. In the arid west, we dam rivers so that people and crops can live in deserts. The land becomes more saline, and the rivers no longer reach the sea.
Before the Europeans came, Minnesota was a natural resource treasure, with forests of virgin white pine and some of the world’s largest deposits of rich iron ore. Deep layers of our glacially deposited soil were nourished by the ample waters of our lakes, streams and aquifers. Now those forests are clear cut, their lumber exported to the world. Most of the iron ore is also gone, leaving behind those empty pits. We need to protect our remaining soil and the waters which nourish it.
All over the earth, this drawing down of nature’s resources continues. More than a billion people are hungry, while the rest of us make a place at the table for nearly a billion cars and trucks consuming their diet of food-based biofuels. The vengeance for these acts of desecration will not be sudden — instead, rivers will gradually silt up the dams, overtop and remove them and resume their destined routes to the sea. Soils, impoverished and eroded from single cropping and excessive fertilizers will no longer nourish our billions. A warming atmosphere, polluted by overuse of carbon fuels, will wreak its own havoc. There is still time, but not much time, to take seriously our responsibility to the earth.
