For the third time, Gov. Christie has refused to link climate change and Sandy.

"I don't think there's been any proof thus far that Sandy was caused by climate change," Christie said yesterday in response to a question from a reporter from WNYC, an NPR affiliate.

Today at a union meeting for teachers, Christie's expected Democratic challenger, State Sen. Barbara Buono, brought up his remark.

"Wake up!" Buono said. "How much proof do you need? This kind of putting his head in the sand, being in denial, is not going to solve our problem. Being in in denial is going to have the future Sandy be the legacy our children are going to inherit."

Immediately after the storm, I asked Christie about the effect of global warming or climate change on Sandy, and he said that kind of question was above his pay grade.

In February, I asked again, and he called the question "esoteric." My subsequent story noted that while scientists cannot link Sandy and climate change, they can say that climate change has led to rising sea levels and more intense storms.

This time, when asked about the issue, Christie went after the messenger -- a reporter from WNYC, an NPR affiliate, which has been reporting about the failure of NJ Transit to properly take into account climate change and protect its trains from Sandy.

Christie told the WNYC reporter: "I would absolutely expect that that's exactly what WNYC would say, because, you know, liberal public radio always has an agenda. And so since I disagree with the premise of your question I don't feel like I have to answer the rest of it."

Environmentalists say the question is important because the answer could guide the state's approach to post-Sandy rebuilding. For example: Should science be used in evaluating whether homes on the Shore should be rebuilt? Should regulations be strengthened to protect the environment from gases that scientists say cause global warming and, possibly, more storms?

Christie said, in August 2011, that climate change is real and that he believes human belngs play a role in it

But Buono doesn't buy it. "He's trying to repackage himself as a moderate, and he's anything but."