We're operating this planet like a business in liquidation.

I understand that being optimistic in this age is challenging, but I am optimistic nonetheless.

As president, I will bring all the parties and stakeholders together. I am going to come up with a solution that respects the environment and does not cause an upheaval in the economy.

I think the cost of energy will come down when we make this transition to renewable energy.

What's at risk [in 100 years] if we do not take action, truly is the survival of civilization as we know it... Literally that is the case. We have seen global warming so far of just a little bit less than one degree Celsius and look at what's happened. Superstorm Sandy. Boulder Colorado. All these fires. Hurricane Irene one year before.

We're putting 70 million tonnes of pollution into the atmosphere every day, trapping an enormous amount of extra heat from the sun inside the earth's atmosphere. It's threatening to push the planet past a tipping point beyond which climate change would be difficult to stop

Adopting a central organizing principle means embarking on an all-out effort to use every policy and program, every law and institution, to halt the destruction of the environment.