Net benefits

摘要

Those who worry about global warming have a simple answer to the problem. Simple in theory, that is: stop pumping carbon dioxide into the atmosphere. In practice that is rather hard to do. But there is another approach. Having put the stuff into the air, take it out. One proven way of doing this is photosynthesis. Measures to nurture and expand the world's forests come high on the agenda of environmental proposals. But new forests take up a lot of land. How about a high-tech alternative: capturing the CO_2 from air by artificial means and tucking it away in the Earth's crust?