There's real economic costs to climate change - So, Superstorm Sandy led to billions of dollars in damages. The fires out in the west, 70 million dollars a day are being spent in fighting fires that have clearly been exacerbated by drought and climate change. So, people have pointed out the true dollars and cents cost of inaction on climate change.

I think it is important for people to understand that there are real serious economic costs and real serious economic damages associated with inaction on climate change.

Many people have the impression that there is significant scientific disagreement about global climate change. It's time to lay that misapprehension to rest. There is a scientific consensus on the fact that Earth's climate is heating up and human activities are part of the reason. We need to stop repeating nonsense about the uncertainty of global warming and start talking seriously about the right approach to address it.

What to do about climate change is political, it's social, and it's moral, which is one of the reasons the scientific community reached out to the Pope, to ask for his involvement in this issue.

Scientific monitoring is going to be terrifically important, because whatever steps we take ... we will have to monitor those steps in order to know if they're actually working.

When we damage the environment, we damage everything we depend on.

Scientists should continue doing what they've always done, which is to understand the Earth as well as they can.