OK, Carnival, write 1,000 times: I will not pollute the water and the air. I will not pollute the water and the air.

Something has got to drive home to Carnival Cruise Lines that it is not all right to send the Fantasy to the port of Charleston when it has scored an F for its environmental footprint.

Environmental advocacy group Friends of the Earth’s recently released Cruise Ship Report Card compares 15 major cruise lines and 148 cruise ships. The good news ... sort of ... is that Carnival Cruise Lines has improved from an F to a D+.

Marcie Keever, oceans and vessels project director for Friends of the Earth, said Carnival’s grade improved in part because it installed shoreside power on two of its ships.

“Imagine if Carnival implemented these changes across its entire fleet,” she said.

At present, imagination will have to suffice in Charleston, where the Fantasy is homeported. The ship scored an F in reducing air pollution.

It also scored an F in sewage treatment, for an overall grade of F. Air emissions have provided the most cause for complaint locally, by far.

The report card indicates that Carnival Cruise Lines could do a better job than it has done — and particularly for the Fantasy. And those improvements would benefit the 3,530 people who might be aboard and the people on shore who breathe the same air.

Adding shoreside electrical power, which allows ships at berth to cut off their emissions-spouting diesel engines, would be a good start. And now would be a good time, since state environmental regulators recently approved the port’s proposed new passenger terminal at Union Pier, which the Fantasy will use.

Shoreside power would almost assuredly pull up the Fantasy’s sad grade.

Charleston City Council, which has so far declined to put any meaningful restrictions on Carnival, should take note of the report card.

Viewed in context with local complaints about the Fantasy, it offers compelling reading — and more evidence that the city shouldn’t be a passive host to the cruise industry.