Monitor: For years, natural gas has enjoyed a reputation as the cleanest fossil fuel because it releases less carbon dioxide into the atmosphere when it is burned than coal or oil.
With technology that allows companies to extract gas from reservoirs trapped in underground shale deposits in the US, domestic gas has become plentiful and cheap. As a result, it is increasingly replacing coal in power generation, and is substituting for gasoline and diesel fuel in fleets of retrofitted vehicles.
But from...