Climate change and rising sea levels may impact the bond ratings of coastal U.S. cities, Honolulu among them. That issue was briefly discussed Tuesday during the first hearing of the Senate Democrats' Special Committee on the Climate Crisis.

Honolulu Mayor Kirk Caldwell attended the hearing, along with mayors from Portland, Oregon, Pittsburgh, St. Paul, and Atlanta, to discuss their efforts to address climate change in their cities.

Sen. Sheldon Whitehouse of Rhode Island asked Caldwell if he is seeing economic impacts from climate change. Caldwell said it was a timely question because he recently gave a presentation to representatives from Moody's Investor Service and Fitch Ratings Inc.

"I've heard from other mayors when I was in Rotterdam for the 100 Resilient Cities," said Caldwell. "Miami, Miami Beach, Dade County are all being asked by Moody's and Fitch, and others, what are they doing to address sea level rise. And it's going to affect their bond rating unless they show what they're doing.

"They're (the credit rating agencies) just concerned about, 'We're issuing bonds. We're rating your bonds. And are you going to be able to pay them back, given what's occurring in your city?'"

Honolulu's municipal bond rating is currently AA+ from Fitch and Aa1 from Moody's.

The Senate Democrats' Special Committee on the Climate Crisis is chaired by Hawaii Sen. Brian Schatz.