The most important problem with renewable resources is that they are on the brink—some have gone over it—of becoming nonrenewable. The amount of usable land, water, and timber decreases rapidly. Land disappears into deserts or under pavement. Every year a million and a quarter acres of rural land, a third of it cultivated cropland, are given over to other uses—chiefly urban expansion. Cities tend to become greedier as they grow; from 1960 to 1970, the land area of urban centers expanded by 40 percent while population grew by 24 percent. At the same time, formerly good rangeland is deteriorating. The Bureau of Land Management, largest manager of land in the country, says 16 percent of its rangelands are declining. The next step for declining rangelands—areas where rainfall is too low or erratic to support forests or unrelated cultivation—is erosion and possibly desertification. Once soil cover is lost from these lands, it can take from 300 to 1,000 years to build up another layer of productive topsoil.
The Relentless March of Deserts – Water Scarcity
The United Nations Environment Programme estimates that humanity has changed 9.1 million square kilometers of potentially productive land into desert. This process is what former UNEP Executive Director Maurice Strong called “the relentless march of deserts.” Water is the answer to some soil problems, but we are already having trouble stretching our water supply. North Americans now remove twice as much water from the hydrologic cycle as we return. In 1970 projected American water requirements for 1980 were about 700 billion gallons, but even technological optimists could only come up with a 1980 supply of 650 billion gallons. To supply water, particularly in the West and Southwest, we have tapped large aquifers—natural reservoirs in underground porous rock. Consequently, water tables have dropped sharply in areas of heavy withdrawal. Some aquifers will take tens or hundreds of thousands of years to replenish, and they may not refill at all if rock from which water was drained is compacted by the earth’s pressure.
Forests Diminishing – Not Quite a Renewable Resource
Land in California’s Central Valley is already subsiding. Replenishing trees cut from forests is a similar problem, although the time spans involved are shorter. A prime example of trees becoming nonrenewable resources are the once-vast redwood forests of California. The remnants of those forests are being clearcut rapidly, even to the point of endangering the world’s tallest trees inside the boundaries of Redwood National Park. Growing more redwoods the size of the ones we are now cutting would take 800 years or more. Unless man uses unprecedented restraint for many centuries, old-growth redwood is a non-renewable resource. Intensive forestry has become the rage in lumbering circles because it provides more wood per acre than other methods. Its practice includes such techniques as clear cutting large tracts and planting even-aged stands of a single species. This is management of trees as a crop, and “tree farm” has come into the language. Anyone can tell where this practice is being carried out, either from peeled hill-sides or from rows of trees of uniform height with no one, waste. Inorganic and organic wastes are a $6-billion-a-year problem. It costs us more than five million Btus of energy to collect and dispose of each of the 125 million tons of garbage we generate each year. But a study for the Ford Foundation Energy Policy Project suggests that crop residues, feedlot manures, and urban refuse could actually be used to generate more than four quadrillion Btus. This figure is expected to more than double over the next 25 years. Waste conversion could take the place of the pro-posed shale-oil industry. While our cities debate where to put the next landfill, they ignore the vast potential of the waste they try so hard to hide. It is easy to understand the main source of our problems with natural resources.
Our Country Was Founded On Exploitation of Resources
When our country was young, we deemed it advantageous to encourage the exploitation of resources. We were even anxious to give away public land to be used for private purposes, believing those uses would benefit the whole country. The country was built with re-sources virtually given to miners and with tax shelters granted to lumbermen. Now that we have built ourselves a culture and a country, we are slow to take back the concessions granted to resource-exploitative industries, even though those provisions harm us now.
