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. Not only that, but in the case of climate change - a scientific issue with strong moral implications and difficult decisions to be made - it's essential to connect the science to our values. And for many of us, our values come from our faith.

If you can frame climate change as an alternate religion, or as one more of those issues where the pointy-headed liberal atheist scientists are trying to discredit the Bible, then you've already got a ton of people on your side who are concerned about heresy, other religions, or teaching evolution in schools.

We need a price on carbon that accurately reflects its real costs on our society and our wellbeing.

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.

We must prepare for a changing climate by incorporating climate preparedness into every aspect of our planning - for food, water, health, energy, even national security. We must reduce our emissions to prevent even more dangerous change.

When I talk to my neighbor, or to someone at church who doesn't accept that the planet is changing, I know that they don't know any better. They've been told this information by somebody they trust and it's not their fault. They've just never heard otherwise.

I think the biggest pushback comes from people who perceive me to be a threat. Having bloggers who are dedicated to making up false information about you, having anonymous people write nasty emails and letters, having organizations file legal requests for your work-related emails, and all the other things that happen can be very depressing and discouraging.