Last month, when the EPA turned down California's request, it was the first such denial in 40 years. It has led to suspicions that the EPA knuckled under to political pressure from the White House, and on Thursday, the EPA administrator took a lot of heat.
"Is this your notion of an open and transparent way to make decisions?" asked Senator Boxer.
It was hardly a collegial atmosphere in the Senate's Environmental and Public Works Committee, especially for EPA administrator Stephen Johnson.
"Do you believe bold action is needed to reduce global warming?" asked Senator Bernie Sanders, D-Vermont.
Nothing near a straight-forward answer was heard by senators Thursday. The Chairman says he said no to California because its waiver request failed to meet legal standards, despite recommendations to approve it by his staff.
"I evaluated the data, made the decision. It was the right decision," Stephen Johnson, EPA Administrator.
Johnson's critics disagree. Among them is Dr. Stephen Schneider of Stanford. He is a leading scientist on climate change who advised the EPA that global warming presents California with compelling and extraordinary threatening circumstances.
"Almost all the EPA scientists said the case is clear. The administrator used legal excuses to say it is not true," says Schneider.
"I was not directed by anyone to make the decisions," said Johnson.
"But on what basis?" asked Boxer.
Senator boxer was appalled that when California asked the EPA to explain those decisions, they received blank documents.
"I'm talking about you sending us blank documents," said Boxer.
In summary, on Capital Hill, a good time was not had -- by anyone.
"Do you believe global warming is a major crisis?" asked Senator Sanders.
"I don't know what you mean by a major crisis," said Johnson.
According to Johnson, his rationale will not remain a mystery, forever. The EPA expects to establish its own emission guidelines next month.