If your incentives are set up wrong - if for some reason you reward people for behavior that's actually bad for your customers or your organization - then you're going to encourage that behavior.

You have to be able to generate usable energy without greenhouse gas emissions and you have to be able to do it cheaply if you want people to choose that approach.

On almost every environmental issue I care about, in fact, I've been wrong at one point or another. I used to think that climate change was no big deal, that most environmental problems were massive exaggerations, that oil reserves were effectively unlimited, and more.

Whatever my current beliefs are, on any topic, they're all open to being changed by the right facts and the right evidence.

Unfortunately, in the environment, I don't see as much willingness to invest heavily in R&D as I do in consumer technology. And that's a pity.

We have climate change caused by greenhouse gas emissions, mostly from human power and transportation infrastructure. At the same time, we have 2 billion people who live in energy poverty.

Often we need to use policy to level the playing field, or to be sure that a technology is managed in a responsible way.