Transparency is all about letting in and embracing new ideas, new technology and new approaches. No individual, entity or agency, no matter how smart, how old, or how experienced, can afford to stop learning.

I love disagreements. I love the democratic process. If I'm in a room where everybody agrees, I start to nod off.

Critics play a dangerous game when they denounce the science and law EPA has used to defend clean air for more than 40 years. The American people know better.

When consumers do not take full advantage of efficiency gains, it is because they are weighing other factors that influence their decision making. When the federal government arbitrarily places one of those factors over others, it makes consumers worse off.

EPA gets to set a standard for new. For the existing, EPA sets guidelines for what we think is appropriate, but then states develop plans that work for them, taking into consideration their specific energy mix.

But just [proposing the standard] puts companies on notice that if you're looking to construct a new natural-gas or coal facility, you really need to pay attention to these. This is what they should be designing new facilities toward as soon as this proposal hits the streets.

Climate change is the greatest threat of our time.