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.

My faith tells me that God does want people to understand climate change and do something about it.

We're not paying a real price for carbon. If we were, we wouldn't be using as much. We need to have the right perspective. It's not just about next quarter's financial return. It's about where we want to be in ten years.

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.

We don't have a hundred years to fix climate change. We don't have a hundred years to wait until we've built all these bridges and rapport and scientific understanding and so on and so forth. We have to fix climate change with the people we have right now, and to a large extent with the perspectives we have right now as well.

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