Last week's announcement that the Environmental Protection Agency is coming down hard on existing coal-fired power plants raises literally hundreds of questions.
Perhaps the only one to which we already have an answer is what the edict will cost.
For tens of millions of American families and tens of thousands of businesses, the answer is a single word: astronomical.
Beyond any doubt, many household electric bills will increase by hundreds of dollars a year as a result of the mandate. Many businesses' costs will skyrocket by thousands or even millions of dollars a year.
For some companies where electricity is a high proportion of expenses, the increase will push them over the edge into bankruptcy. That already has happened in some places.
On June 2, EPA Administrator Gina McCarthy signed orders to reduce carbon dioxide emissions from U.S. power plants by an average of 30 percent. Though the full impact of the mandate is not expected to take effect until 2030, states must submit compliance proposals by 2016. Utilities already are under the gun to plan how they will bring power plants into compliance.
Truth be told, most electric companies anticipated the ruling years ago. President Barack Obama has made his agenda - shutting down coal-fired power plants - very clear.
Utilities already have closed or announced plans to shutter as many as 300 coal-fired generating units throughout the country. Existing rules essentially banned them from constructing new coal-fired plants. A shift toward stations fueled by natural gas already is under way.
The new rule will cost us dearly.
Congress can prevent that from happening. Perhaps the most crucial question of all is whether lawmakers will do that.