What Can Be Done?
Ideas for combating the greenhouse effect are proliferating as fast as global pollution. Some are promising. Others are not.
1 SOLAR ENERGY: The use of solar energy has faded from public view in recent years, largely because of falling oil prices. In the meantime, however, dramatic gains have been made in the efficiency of solar cells. As The New York Times reported recently, for the first time, “the conversion of solar energy to electrical power could become comparable in efficiency to conventional power generation.” If solar energy becomes truly competitive, this technology could help reduce greenhouse emissions as solar power plants replace conventional ones.
2 HYDROGEN FUEL: This is an idea that is at least technologically feasible—the use of pure hydrogen, instead of petroleum products, as a fuel for airplanes and perhaps even automobiles. From a ‘greenhouse’ standpoint, the advantage of hydrogen fuel is that it is very clean burning. There is no carbon dioxide produced at all in hydrogen combustion, just steam. Hydrogen is an excellent source of energy. In fact, pound for pound it will keep an airplane flying for three times as long as jet fuel will. One problem is that it is also three times as expensive. A larger problem is that liquid hydrogen must be kept very cold and under pressure. Any leaks in the fuel system could lead to a disastrous explosion, as in the case of the American space shuttle Challenger.
3 SPACE SHIELDS: Huge “parasols” in outer space made of thin plastic that would cast giant shadows on the earth have been proposed. It would require satellites with an area equal to 2 percent of the earth’s surface to compensate for the anticipated doubling of carbon dioxide. This plan would not be popular with astronomers!
4 GLOBAL REFORESTATION: Did you know that highly efficient, nonpolluting, self-maintaining devices already exist for carbon dioxide removal from the atmosphere? They are plants. Green plants use carbon dioxide as food, keeping the carbon for their own use and returning the oxygen to the air as waste matter. All things being equal, an increase in carbon dioxide should stimulate plant growth worldwide, which would tend to use up the extra carbon dioxide and help control the greenhouse effect. But, sad to say, all things are not equal where plants are concerned. The plants that are able to remove the most carbon per acre are trees, and trees are being chopped down all over the world at an appalling rate.
In the face of this global trend, many scientists are urging massive reforestation to combat the greenhouse effect. They point out, for example, that ten million acres [4,000,000 ha] of trees could absorb all the carbon dioxide emitted by power plants in the next ten years. Programs to reach this goal at a cost of thousands of millions of dollars were discussed at Senate hearings in the United States a year ago.
Such a program might succeed in the United States, but what about the Tropics? Tree-planting incentives are not very appealing to starving, desperate people where trees are being destroyed to clear land for crops. However, the world’s tropical rain forests are part of the oxygen-producing lifeline for the entire planet, and they are being slashed, burned, and butchered. Will the lifeline be cut?
5 CFC DEATH RAYS: Giant lasers could be fired from earth into the atmosphere, tuned to energy frequencies that chlorofluorocarbon gases absorb. Hopefully this energy will blast apart the CFC molecules before they rise to the stratosphere and attack the ozone layer. Problems with this include the expense and energy requirements of the lasers and “whether you can get the laser’s energy absorbed by CFC’s and not other molecules, such as water vapor and carbon dioxide,” according to Princeton University physicist Thomas Stix.
6 SOLAR POWER SATELLITES: Giant arrays of solar cells in space could collect solar energy continuously without stopping for clouds or night. The energy would then be beamed down to earth as microwaves or laser beams. The idea is to use solar energy instead of burning more fossil fuels. The technical obstacles and scale of the project are daunting.
[Diagram/Picture on page 8, 9]
(For fully formatted text, see publication)
1 SOLAR ENERGY
2 HYDROGEN FUEL
3 SPACE SHIELDS
4 GLOBAL REFORESTATION
5 CFC DEATH RAYS
6 SOLAR POWER SATELLITES