Nicholas Stern

We can look back through ice-core data and see over 800,000 years, relationships between carbon dioxide and the temperature of the world. So those people who deny the importance of climate change are just wasting their time. They're also being diversionary because if we don't act the risks are enormous.

If coal is going to be used, the only response - because it is the dirtiest of all fuels - is that we have to learn how to do carbon capture and storage and we have to learn how to do it quickly on a commercial scale.

The basic scientific conclusions on climate change are very robust and for good reason. The greenhouse effect is simple science: greenhouse gases trap heat, and humans are emitting ever more greenhouse gases.

I'm no longer just a candidate. I'm the President. I know what it means to send young Americans into battle, for I have held in my arms the mothers and fathers of those who didn't return. I've shared the pain of families who've lost their homes, and the frustration of workers who've lost their jobs.

As a small business owner for the last 15 years, when I think of what truly changed my life, it was my faith, a strong family, my mom did a really, really good job of encouraging me in very clear and discernible ways.