The threat of global warming may not be as dire as some experts say,but Americans should be making changes in the way they consume energy, a Baltimore Gas & Electric Co. official said.

Ted G. Ringger, supervisor of air and water quality for BG & E, spoke on "The Greenhouse Effect Theory" at the monthly Agribusiness breakfast Thursday at Baugher's Country Restaurant.

He offered a simple explanation of the greenhouse effect: The atmosphere allows the sun to strike the Earth, but gases in the atmosphere trap and retain some of the heat, keeping the planet warm.

That's not necessarily bad, but the concern is that the climate could change drastically as more gases are emitted and trapped, said Ringger, who works out of Anne Arundel County.

Four types of gases are a concern, he said. They are methane, nitrous oxides, carbon dioxide and chlorofluorocarbons.

The 1980s produced four of the warmest years on record, Ringger said.

"Global climate change is here. It's happening right now," he said.

Some people suggest phasing out fossil fuels, such as coal, or using more nuclear power, Ringger said. Solar, tidal, wind and geothermal power also are alternatives, he said.

"Think more about conservation," he suggested. "It's the right thingto do regardless of whether there is a problem."

Nuclear energy, widely used in Europe, probably won't be a popular option in the United States any time soon, Ringger said.

"The problems with nuclear power are more political and with the public's perception than technical," he said.

The Earth's temperature has not changed much for most of history, he said.

"Climate has a cyclical nature with short-and long-term ups and downs," Ringger said.