Maybe it’s the record heat we just experienced in Washington, but I am very confused.

Since last summer, GOP presidential candidate Mitt Romney has been saying that “we don’t know” if humans are causing climate change — flipping in the opposite direction from his earlier position as Governor, when he called for a “no regrets policy” on addressing climate change.

But as we head into the general election, a surrogate from the Romney campaign now indicates the candidate has again changed his stance, declaring that he is “certainly not a denier” of climate science.

Speaking at a debate on energy issues today between representatives of the Romney and Obama campaigns, former Deputy Secretary of Energy Linda Gillespie Stunz implied multiple times that Mitt Romney would be open to action on the issue.

Stunz mostly danced around the questions on climate, criticizing EPA regulation of greenhouse gas emissions and dismissing any domestic action without more international coordination. But in providing her answers, she also strongly hinted that a Romney Administration would engage in international talks on reducing greenhouse gas emissions.

“It’s a huge challenge. But it’s one that Governor Romney would face up to by continuing dialogues … with other countries. This is not a problem that can be addressed by the U.S. alone,” said Stunz, speaking at an event put together this morning by the Business Roundtable.

She was debating Dan Reicher, former assistant secretary for energy efficiency and renewable energy, who spoke on behalf of the Obama campaign.

Stunz also said there “needs to be more research on adaptation. He’s certainly not a denier, he certainly thinks there’s more room for research.”

Stunz’s comments mark a noticeable shift in rhetoric that potentially complicates the Romney campaign’s messaging. Now that a representative for the campaign is back on record claiming (in a round-about way) that Romney believes climate change is an issue that needs to be addressed, does that now mean he will begin talking about it during the general election?

Up until now, Romney has been focused exclusively on appealing to voters on the extreme right — and in the process turned his back on previous support for efficiency, renewable energy, and reducing carbon emissions.

But with polls showing that that a large majority of Americans understand that climate change is accelerating, support government action on the issue, and strongly desire more renewable energy, the Romney campaign may be faced with another decision: Should the candidate flip back to a more moderate stance?

They may need to bring out the Etch A Sketch on this one.

We’ve come to expect changes like this from Romney, a candidate who has drastically altered his position on virtually every issue. But it’s one of Stunz’s other comments that really has me confused.

In describing appropriate ways to limit carbon emissions, she said Romney believes that initiatives already in place — things like fuel economy standards, appliance standards, and efficiency targets — are the solution to lowering carbon emissions.

“We are effectively de-carbonizing our economy in ways that we had not foreseen,” said Stunz, referencing measures undertaking by the Obama administration.

Wait a second. Didn’t Romney say last December that he would roll back existing fuel economy standards? And don’t I also remember him falsely claiming that new light bulb efficiency standards meant the government had “banned” incandescent lights?

So which is it?

Romney’s campaign has twisted itself into knots on the issue of climate change, and it’s unclear where the candidate will stand when he’s finally untied himself.