On carbon dioxide and global warming: About 100 billion tons of carbon in the form of carbon dioxide circulates between the Earth, oceans and atmosphere each year. This is the natural stuff and would go on without human activity. Each year human activity in the form of fossil fuel burning adds about 5 billion tons to this natural circulation. The United States now has about 100 nuclear power plants generating 20 percent of our electricity. If we should add another 100 nuclear plants and replace equivalent coal generation, we would reduce that worldwide 5 billion tons of carbon added to the atmosphere each year by 3 percent.

Petroleum use in Maine: In 1960 the Maine residential sector used about 7.2 million barrels of petroleum (propane, kerosene and furnace oil). In 2002 that use increased to about 8.5 million barrels. The Maine population growth over this period was about 30 percent – our use of residential petroleum increased a bit less than 30 percent. Petroleum use for all purposes was 27 million barrels in 1960 and 42 million barrels in 2002. That growth is greater than the population growth. Each household’s share of total Maine petroleum use is about 60 barrels.

Richard Hill is a retired professor emeritus of engineering at the University of Maine.