We need the economic and regulatory certainty to invest in a low-carbon energy future.

On the other hand, we can't really predict the future of these systems with much certainty.

The committee has held hearings on climate change issues for nearly 30 years. The first one was in 1978 when I was still on staff. It's time to act.

It is critical that we start now.

The unfortunate thing for those seeking certainty is that the only thing certain is that they will be unable to find it.

It is far better to foresee even without certainty than not to foresee at all.