President Obama established rules which will require new electricity generating plants to emit less carbon. He promised to deal with emissions from older coal plants in the future. One solution, proposed in this article, is to require coal burning plants to reduce mercury emissions. The older coal burning plants, which are not equipped with modern scrubbing technology, would not be able to satisfy that requirement. They would be forced to switch to gas which is cleaner and becoming less costly. The National Academy of Science estimated that the cost to society from burning coal in 2005 was $62 billion. We could provide pensions to the coal miners who lost their jobs for a fraction of that cost to society. Unfortunately, our accounting systems do not account for the cost of externalities.
One approach for dealing with carbon emissions from older coal plants is to capture and store the carbon underground. That technology has not been tested on a large enough scale to determine its effectiveness.