Gov. Andrew Cuomo wasn’t taking any chances that there might be empty seats at a speech he delivered last week on climate change — so state workers were summoned on the taxpayer dime to fill the audience, The Post has learned.

The workers said they left their jobs in the middle of the day Thursday and were paid their full salaries to hear Cuomo at Columbia University announce the state was joining a global effort to reduce greenhouse gas emissions.

“I’d rather be at the park,” said one of the workers, who is employed by the state Office of Parks, Recreation and Historic Preservation and who has no connection to climate issues.

He explained that he went because his boss “asked me to make some time available in my schedule.”

The worker confessed that he didn’t know what the event was about before he agreed to go.

He said attendance is not required, but is viewed favorably, and that the practice is common throughout state government to support Cuomo.

“They often ask,” he said, referring to supervisors. “We get emails, and they’ll ask us if we want to go.”

The worker said he would not have volunteered if he were not getting paid his regular salary. “It’s better be on the clock,” he said.

The 2:30 p.m. event, which lasted about an hour and included speeches from former Vice President Al Gore as well as Columbia President Lee Bollinger, focused on Cuomo’s plan to have state agencies work with other states and cities worldwide to reduce carbon emissions.

A state Department of Health worker told The Post that supervisors offered employees the ­option of attending the event ­“instead of working.”

If they watched Cuomo, they could go home afterward instead of returning to work, the employee said.

He called the practice “AstroTurfing” — an attempt to fabricate grassroots support.

“Public employees take an oath that they won’t use their position for their personal advantage,” the employee said. “How can you expect any state workers to take it seriously when the boss isn’t leading by example?”

Good-government advocates questioned why state workers were being paid to attend an event designed to bolster an elected official’s credentials.

“It’s a questionable use of state resources,” said Dick Dadey, executive director of Citizens Union.

A Cuomo spokesman acknowledged that state workers attended the Columbia event, but insisted that was proper.

“A handful of staff from relevant state agencies had the opportunity to attend this important announcement, which impacted their work. They were a small number of the more than 500 people who attended the event,” said spokesman Frank Sobrino.

He said about 20 workers went from four agencies, including Environmental Conservation and the state Energy Research and Development office and decisions on whom to send were made “at the agency level.”

He also said that climate issues are “directly relevant” to health employees and are “an enormously important issue” to parks workers after Hurricane Sandy.