For many of us, our values come from our faith.

The word "evangelist" means someone who spreads good news. Studying the impacts of climate change as I do, it's hard to come up with good news. In many ways I feel more like a Cassandra or a Jeremiah than a good-news evangelist.

There is no set period of time or total amount of carbon emissions that we can stay below to ensure we stay safe.

Our carbon emissions have to eventually go to zero. We have to. Otherwise we're never going to have a stable climate and that's what our goal is for human civilization to thrive, a stable climate. We don't want one that's hotter, we don't want one that's colder, we want one that's stable.

There's no question that natural gas is a lot better than coal or oil, in the sense that natural gas produces less carbon per unit of energy produced.

It's a common perception that science and religion are mutually exclusive. But there are many scientists who would consider themselves to be spiritual people.

It is certainly true that conservative Christians are much more likely to doubt the reality of climate change than mainline Christians or the unaffiliated. But when we control for political affiliation and for the important role of thought leaders in determining our opinions on social issues such as climate change, most of the faith-related bias disappears.