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Many possible solutions have been proposed to stave off global warming, should it actually be occurring. Some are very practical, while others are grandiose, to say the least. What is certain is that as the world's population continues to grow and developing nations develop, the world's need for space and energy will continue to grow. The need for space will accelerate deforestation. The need for energy will almost certainly increase the rate of fossil fuel burning. Listed below are a number of proposed "solutions" to combat global warming.

The simplest solution is an old one: conservation. Each gallon of gasoline releases 8.64 kg of CO2 into the atmosphere (source USEPA). Each kilowatt of electricity generated by a coal-fired plant produces about 1.4 kg of CO2 (source USEPA). Use less = emit less. The USEPA estimates that energy-saving appliance standards in the U.S. will have reduced national electricity consumption by 3% by the year 2000. This reduction will offset the need for 31 large power plants. A 625 MW coal-fired plant (serves about 425,000 homes) emits 1 million tons of carbon each year. The best part about conservation is it also saves you money. Again, the USEPA estimates that consumers will save more than $140 billion by the year 2030 with energy-saving appliances.

Plant a tree. Forests cover 10 billion acres worldwide and sequester 1 trillion tons of carbon. The IPCC estimates that 850 million acres could be made available for planting trees. These trees would take up 60 to 90 billion tons of carbon by the year 2050. Unfortunately, this is only 12 to 15% of projected emissions during this period. Moreover, trees mature and stop rapidly consuming carbon. They are cut down, burned, or decay, which releases their stored CO2. So trees are a temporary partial solution at best. However, if these trees were used for lumber or paper products, their carbon would be stored for much longer periods of time. This might give the next solution time to work.

The oceans. The oceans already hold 36 trillion tons of carbon and absorb an additional 10 GtC from the ocean surface components each year (see Carbon Cycle). The ocean surface currently absorbs 2.5 GtC from the atmosphere, or roughly 40% of anthropogenic emissions. Given time, the oceans will probably absorb human-induced emissions, just not as fast as we are currently producing them. Proposals have been made to pump power plant emissions directly into the deep ocean. It would probably work, but would be extremely expensive.

John Martin, a scientist at Moss Landing Marine Laboratories in California, proposed in 1986 that we seed the oceans with iron to cause phytoplankton blooms. Such blooms would consume huge quantities of CO2, and when the plankton die in a couple of weeks they would sink to the bottom and thus sequester their CO2. Two small trial experiments have shown that it might work. The environmental impact on other creatures in the ocean has yet to be assessed.

Human fat is 76% carbon. What if all 6.5 billion humans gained a kilogram of fat? This would sequester 4.7 MtC, which is only 0.077% of the yearly emissions from anthropogenic sources. Not worth it. On the other hand, you're not contributing much to global warming when you lose weight.

Reduce the amount of incoming solar radiation. There are several ways to do this. Increase cloud cover. Shoot sulfur into the stratosphere like volcanic eruptions do. The National Academy of Sciences estimates it would cost the U.S. about $250 to $500 million a year to offset its emissions this way. This is ironic, since we limit power plant emissions of sulfur into the troposphere. Routinely send a trillion Mylar balloons into the upper atmosphere to reflect sunlight away. Unfurl a 1200 mile long thin shield, 930,000 miles from Earth to reflect solar radiation. This would reflect 2% of the sun's energy. To reduce costs, the shield would need to be manufactured on the moon.

To counter sea level rises, add snow to the east Antarctic ice sheet. The 3 trillion tons of sea water needed each year would be sprayed out as snow on the ice cap, using technology much like ski slopes use to make artificial snow.

Stop burning fossil fuels to generate electricity. Alternatives: Solar cells, hydropower, wind power, nuclear power. Drawbacks: Solar cells are not yet practical or cost efficient. Will not work in high latitudes or cloudy areas where sunlight is not steady or intense. Hydropower is a regional solution. The question must be, Do we want to dam every beautiful river to generate electricity? Wind power is also a regional solution of limited capacity. Conventional nuclear power (based on fission) has fallen out of favor in the U.S. because the spent fuel rods are highly radiactive and must be stored for several million years before they are safe. Also, there is only a limited supply of uranium for use in nuclear reactors. A possible solution is nuclear fusion. This is the process which powers the sun. The technological problems for practical nuclear fusion power are enormous. However, fusion is a relatively clean (spent materials would need to be stored for less than 100 years) and there is a nearly limitless supply of fuel in the world's oceans. Because of the technological problems, the U.S. is lagging far behind the rest of the world in developing fusion power.

Many of the solutions were taken from an article by Ruth Flanagan in the Oct. 96 issue of Earth magazine, pgs. 34-39.

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