Bury the trees--and C[O.sub.2]--in the ground.

Of the current global environmental problems, the excessive release of carbon dioxide from the combustion of fossil fuels (and the related global warming) is among the most pressing, maintain a number of scientists. Proposing a new approach to an old solution concerning this dilemma are Fritz Scholz and Urich Hesse from the University of Greifswald, Germany, who say that deliberately planted forests--once they bind C[O.sub.2] through photosynthesis--should be removed from the global carbon cycle by burial.

Whereas other environmental difficulties can, at least in principle, be solved by the appropriate modern technology, "there are no realistic solutions for the C[O.sub.2] problem," contends Scholz. At present, 32 gigatons of carbon dioxide are released into the atmosphere every year. Previous proposals to pump this greenhouse gas into the oceans are not practical--or are ecologically problematic. The only way to bind sufficiently large quantities of C[O.sub.2] from the atmosphere is photosynthesis. However, the resulting biomass cannot be burned or composted, because that would release the bound C[O.sub.2]. The trick is to make the bound biomass "disappear." Scholz recommends planting forests whose wood subsequently would be buried in brown coal pits or other surface mines. Cut off from the air, the wood would not change, even over long periods. It even could be dug up in the future and used.

A little more than 1,000,000,000 hectares of forest would have to be planted to bind all the carbon dioxide produced in a year. This corresponds roughly to the surface of virgin forest cut down in the last century. The project could be financed by an additional tax on gasoline or electricity.

"The forests should be planted in countries that are suitable for growing them and also have the necessary sites for burial of the wood," stresses Scholz. "Other nations, the primary consumers of fossil fuels, can pay for it This would produce a global trade that would be of benefit to everyone involved."