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.

For Christians, doing something about climate change is about living out our faith - caring for those who need help, our neighbors here at home or on the other side of the world, and taking responsibility for this planet that God created and entrusted to us.

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

I feel like a physician, one who's done a scan of the patient's body and seen evidence of a potentially serious issue.

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.

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.

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.