Speaker Nancy Pelosi (D-CA) has not yet settled on either her plan for cap and trade legislation or the purpose of such legislation. In the San Francisco Chronicle she says:

The speaker disappointed environmentalists when she said earlier this month that she may not bring climate change legislation to the House floor this year because it may lack the votes needed for passage. “I’m not sure this year, because I don’t know if we’ll be ready,” she told Capitol Hill reporters. “We won’t go before we’re ready.”

But in the interview Wednesday, she shifted her stance, saying she plans to move the bill this year. She said she hopes to hold a vote before December, when climate negotiators gather in Copenhagen, Denmark, to work on a successor to the treaty many countries adopted in Kyoto, Japan, in 1997.

“I believe we have to because we see that as a source of revenue,” she said, noting that proposed cap-and-trade bills would raise billions of dollars by forcing major emitters to buy credits to release greenhouse gases. “Cap-and-trade is there for a reason. You cap and you trade so you can pay for some of these investments in energy independence and renewables.”

If the point of the policy is indeed to raise revenue for investing in innovation, then we can do a much better job than by creating a bloated cap and trade program by simply establishing a low carbon tax, as Chris Green and I argued recently (PDF). Politically, Pelosi’s continuing fickleness on cap and trade does not foreshadow a successful legislative effort.