In a growing number of states, conservatives have been taking a rather novel approach to climate change — simply preventing people from talking about it.

Florida state employees say they were barred from using the term "climate change"

There's a big uproar in Florida this week after an investigation alleged that the state has an unwritten policy barring environmental officials from using the terms "climate change" or "global warming" in their work. On Monday, Republican Governor Rick Scott denied any such policy was in place. But state employees and outside scientists insist there's heavy pressure not to talk about the topic, despite the fact that Florida faces a serious threat from future sea-level rise.

If so, it wouldn't be the first time state officials — Republicans, usually — have taken steps to prevent people from discussing global warming or climate science.

In 2012, North Carolina's GOP-controlled state legislature passed a law to prevent the state from considering the most up-to-date climate science in formulating predictions of rising seas. In Pennsylvania in 2014, back when Republican Tom Corbett was governor, one former state employee alleged that she was ordered to remove references to "climate change" from the conservation agency's website.

In a somewhat different vein, states such as Tennessee and Louisiana have been passing laws making it easier for teachers in the classroom to present alternative theories to climate change — even though there's a broad and firm consensus among climate scientists that human activity is responsible for the rise in global temperatures over the past 50 years.

Florida: Don't use the term "climate change"

On Sunday, an investigative report alleged that Florida has an unwritten policy barring officials in the Department of Environmental Protection from using the terms "climate change" and "global warming" in any official communication.

In Florida, 2,120 square miles of land sits less than three feet above the high-tide line

The story, by Tristram Korten of the Florida Center for Investigative Reporting, says the policy came into effect after Republican Gov. Rick Scott took office in 2011. On the campaign trail, Scott said, "I have not been convinced" that humans are causing global warming.

This is all despite the fact that the state faces huge risks from sea-level rise — roughly 2,120 square miles of land sits less than three feet above the high-tide line. Climate scientists have warned that global sea levels could rise between one and four feet by 2100, thanks to warmer temperatures, expanding ocean water, and melting ice caps. It becomes much harder for Florida to plan for that if climate change can't even be discussed.

Scott, for his part, has denied that any such policy to mute discussion exists: "First off, it's not true," he said at a press conference on Monday. He then switched the subject by noting that the state has been investing in flood mitigation and beach renourishment — a move he often used when asked about global warming in his 2014 re-election campaign, Marc Caputo of Politico points out.

Yet a number of Florida officials insist they were pressured not to mention climate change. The Coral Reef Conservation Program, for instance, was urged not to use "climate change" when talking about threats faced by the state's coral reefs.

Likewise, in 2010, the Florida Oceans and Coastal Council's Annual Research Plan contained 15 references to climate change (including a section called "Research Priorities — Climate Change"). In the 2015 version of the report, climate change is only mentioned once — an extraneous reference that state employees told Kortem must have slipped past the censors.

North Carolina: Use less science in sea-level predictions

Back in 2012, North Carolina's GOP-controlled legislature passed a law preventing state officials from using the newest science in sea-level rise projections.

Here's what that means: Sea levels along the North Carolina coast have risen about eight inches since 1880 as the planet has gotten hotter. But scientists have argued that this pace is likely to accelerate in the decades ahead, as more ice in places like Greenland and Antarctica melt. All told, the state's Coastal Resources Commission predicted, sea levels could rise another 39 inches this century.

Projections of higher sea-level rise would be bad news for developers

That was bad news for developers — it would threaten some 2,000 square miles of coastal property, putting permits in jeopardy, forcing new flood zones to be drawn, waste-treatment plants to be built, and roads to be elevated. If true, the projection would force the state to spend hundreds of millions of dollars.

So the legislature passed a bill saying that it wasn't true. Instead, all projections of future sea-level rise have to be based solely on past sea-level rise, at least for the time being. If sea-levels had risen eight inches in the past century, then surely they'd only rise eight inches in the next century. Never mind what climate scientists were saying about acceleration.

The bill's Republican backers, for their part, say they just want to take a "breather" and allow time for more accurate projections to emerge. "We just need to make sure we're getting the proper answers," said State Rep. Pat McElraft, who drafted the law.

In a similar vein, in 2014, North Carolina's Department of Environment and Natural Resources also decided to remove all references to climate change from its website. The agency told Climate Progress that these links didn't matter because there were few federal regulations on climate change, anyway. (You can parse the full statement here.)

Pennsylvania: Take "climate change" off the website

Also in 2014, a state employee with Pennsylvania's Department of Conservation and Natural Resources — which regulates natural-gas drilling — said she was ordered to remove references to "climate change" from the agency's website.

Here's how the Allegheny Front reported it: "Adrian Stouffer, formerly the marketing manager for the agency’s Office of Education, Communications and Partnerships, said she and other DCNR staffers were called into a meeting in the Governor’s offices in early 2012, and told to remove ‘climate change’ "in cases where we looked like we were giving a position" on the issue. That meant taking down mentions of the scientific consensus that humans are causing global warming."

A spokesperson for the agency justified it this way: "Agencies typically review websites to determine if information being communicated with the public is consistent with policy platforms of the new administration," she said. "That was done several years ago, and we had about a half dozen places on the websites DCNR maintains where we made some changes to existing language."

Pennsylvania's Republican governor at the time, Tom Corbett, was no fan of addressing climate change. As Emily Atkin of Climate Progress pointed out, he also defunded programs to research the impacts of climate change on Pennsylvania and scrapped programs to encourage renewable energy development and conservation.

In the 2014 election, Corbett lost his bid for re-election to Tom Wolf, a Democrat who has put a much higher priority on promoting clean energy and tackling global warming.

Tennessee and Louisiana: Teach the controversy!

On the other end of the spectrum, some conservative state legislatures want to talk more about climate change. It's just that they're mostly interested in discussing alternative theories.

In 2012, Tennessee enacted a law that made it easier for teachers to present alternative theories to climate change. As Reuters reported, the law mainly provides protection for teachers who "help students understand, analyze, critique, and review in an objective manner the scientific strengths and scientific weaknesses of existing scientific theories covered in the course being taught."

The only problem with that? Advocates of scientific education say it makes it easier for teachers to promote creationism or climate-change denial. Louisiana already has a similar law on the books.

For the record, climate scientists say they are 95 percent certain human influence has been the dominant cause of global warming since 1950. They're about as sure of this as they are that cigarette smoke causes cancer.

Further reading: Thanks to both Climate Progress' Emily Atkin and LiveScience's Tanya Lewis to the pointer for some of the examples here.