President Obama will deliver his 2013 State of the Union address tonight, and expectations are high that he will devote significant time to climate change. We hope that he adopts a different approach to explaining the need for action than he did in much of his first term.

In past addresses, talking about green jobs didn't work, nor did talking about energy independence. The credible way to justify fighting climate change is to discuss the science, the real reason to cut carbon emissions. There is overwhelming evidence that the planet is warming.

The widespread burning of fossil fuels, meanwhile, pumps heat-trapping greenhouse gases into the atmosphere every second. There is still uncertainty about exactly how sensitive the climate system is to a given increase in carbon dioxide concentrations -- but not enough uncertainty to justify ignoring the risks of rising temperatures.

Putting a slowly rising, significant price on carbon emissions would encourage people to burn less fossil fuel without micromanaging by Congress or the Energy Department. This approach would enlist market forces to green the energy sector. It would also allow for similar policies in other nations to connect with America's, creating a bigger, global market for carbon.

Anything like carbon pricing must get lawmakers' approval, though, which is the first reason Obama should make reaching out to them on climate policy a priority. True, a coalition of antiregulation Republicans and coal-state Democrats killed the last major effort to price emissions, a 2010 cap-and-trade bill. But, in the big budget reform politicians have been promising, they will need new revenue from somewhere. A carbon tax would be an ideal source.

Even second- and third-best alternatives would need Congress's say-so. These include establishing a national clean-energy standard requiring that a defined and rising amount of electricity come from sources cleaner than coal, the top climate villain.

Sen. Lisa Murkowski of Alaska, the Energy Committee's lead Republican and a voice of reason within her party, just released a 121-page plan with other ideas that could serve as a basis for some congressional action, such as paying for energy technology research, reforming subsidies for green power, advancing hydropower and promoting energy efficiency.