Another top priority for my energy and global warming agenda will be changing the cars we drive and the fossil fuels we burn. I will increase fuel efficiency standards by 4% per year, lift the 60,000-permanufacturer cap on buyer tax credits to encourage more Americans to buy ultra-efficient vehicles, and encourage automakers to make fuel-efficient hybrid vehicles. Domestic automakers will get either assistance shouldering their health care legacy costs in exchange for investing 50 percent of the savings into technology to produce more fuel-efficient vehicles or generous tax incentives for retooling assembly plants.

I proposed a National Low Carbon Fuel Standard tao reduce the lifecycle greenhouse gas emissions of passenger vehicle fuels sold in the U.S. by 10 percent in 2020 and require additional reductions of 1% annually thereafter.

A successful approach to climate change requires that all major emitting nations actively participate in the solution. Unfortunately, the current administration, instead of trying to improve the Kyoto Treaty by including oil guzzlers like China and India, walked away from the entire global effort to stem climate change. If we must take the first step, our second and third steps must be conditioned on meaningful participation by all countries. This is also an enormous opportunity for us to provide our technological developments to these nations so they can leapfrog to cleaner technologies.

As president, I will enact a cap on our country’s greenhouses gases with a goal of an 80 percent reduction by 2050 – the level scientists warn us we must get to in order to limit the most damaging impacts of climate change. Getting our own house in order is the vital first step in assuring we can get the rest of the world’s major polluters – like China, which just passed us as the world’s largest emitter – to agree to binding caps.

And as we impose our own cap, we must lead constructive international negotiations of a follow-on protocol to Kyoto, whose first phase expires in 2012, that tackles decisively the challenge of climate change.

CBS News: Katie Couric Asks The Candidates In "Primary Questions:" Is The Global Warming Threat Overblown?

Obama: No, I think they're serious. We have to take significant steps now to deal with it. So I've put forward a very substantial proposal to get 80 percent reductions in greenhouse gases by 2050. That is going to require that we change how power plants operate. That's going to require that we increase fuel efficiency standards, that we develop clean and renewable sources like solar and wind and biodiesel.

And, you know, we're going to have to charge for pollution and create a market for pollution abatement and create green technologies that can, over the long term, generate jobs and entrepreneurial opportunities all over the country. But we've got a moral obligation to deal with this. And you're already seeing the effects in not just the United States but all around the world in ways that ultimately could affect our national security.