Matt Yglesias has a plan to finesse the Democratic position:

I think climate hawks are making a dangerous mistake by not engaging more deeply with deficit hawks. One thing that both the Simpson-Bowles and Domenici-Rivlin proposals make clear is that some conservatives now are prepared to concede the need for higher taxes. But they want a hefty chunk of that revenue to come from regressive sources, and they want at least some progressive votes for it. Now, as Paul Krugman argues regressive taxes aren’t as bad as many people think.

But the fact of the matter is that a VAT as proposed by Domenici-Rivlin is always going to be a very hard sell for the left. This, tough, is where climate hawks can come to the rescue of the cherished ambitions of the center-right. Swap out a VAT and swap in a tax on climate pollution, and we become a constituency that’s not just “willing” to swallow the tax but eager to do so. Putting a price on climate pollution isn’t the only thing to be done in an environmental policy, but getting it done would be a huge step forward.