The Heartland Institute is trying to nurture the next generation of climate change deniers.

The conservative and libertarian think tank has sent out 25,000 copies of the organization's book, Why Scientists Disagree About Global Warming, and an accompanying 10-minute DVD to 25,000 science teachers this month, according to a Frontline report. The book argues that climate change is not settled science.

Katie Worth, who authored the Frontline report, called the effort a "massive propaganda campaign by the nation's leading climate change skeptical think tank."

The Heartland Institute, which has received funding from polluting industries such as Exxon and the Koch family, rejects the scientific community's widespread consensus that human activity causes climate change.

The organization plans to send the materials to another 25,000 teachers every two weeks until every public-school science teacher in the nation has a copy, Heartland president and CEO Joseph Bast said.

This means the book and DVD could end up in the mailboxes of more than 200,000 K-12 science teachers in the country. The campaign began in mid-March.

Frontline also published a cover letter of the materials from Lennie Jarratt, project manager of Heartland's Center for Transforming Education, who asks that the teacher "consider the possibility" that climate science is not settled.

The 2015 book is coauthored by Drs. Craig D. Idso, Robert M. Carter and S. Fred Singer, who have been heavily involved in the "debate" over global warming.

Here are some tidbits about the authors:

According to DeSmog, Idso believes that "CO2 is not a pollutant" and is the chairman and former resident of the Center for the Study of Carbon Dioxide and Global Change, which has a mission is to "separate reality from rhetoric in the emotionally-charged debate that swirls around the subject of carbon dioxide and global change."

Carter, who passed away last year, was an Australian marine geologist and a paid climate change denier, SourceWatch noted. He once asserted that the Intergovernmental Panel on Climate Change has not found evidence that global warming was caused by human activity.

Singer, a former space scientist and government scientific administrator, founded the Science & Environmental Policy Project in 1990, a 501(c)(3) "educational group" focusing on global warming denial, according to DeSmog. Idso and Singer helped develop the Heartland Institute's "Nongovernmental International Panel on Climate Change. Singer said in Jan. 2016 that "the real threat to humanity comes not from any (trivial) greenhouse warming but from cooling periods creating food shortages and famines."

The letter directs teachers to visit Izzit.org to access an online guide to using the DVD. Izzit.org is a "right-wing advocacy organization" that provides free educational videos to U.S. educators and homeschoolers.

The National Center for Science Education, an Oakland, California nonprofit that monitors climate change education in classrooms criticized the mailing campaign.

"It's not science, but it's dressed up to look like science," NCSE executive director Ann Reid told Frontline. "It's clearly intended to confuse teachers."

Climatologist Michael Mann also tweeted that the Heartland Institute is trying to "indoctrinate children with climate denial propaganda."

Bast, Heartland's president, said that some teachers have appreciated the information and even asked for a Heartland speaker to visit a class.

However, many science teachers have not welcomed the campaign.

As Frontline wrote:

Lori Baker, a sixth-grade science teacher at North Putnam Middle School in Roachdale, Indiana, found the package in her school mailbox and was dismayed by its contents. "I read quite a bit of the book, actually, and it was extremely frustrating. It's an attempt to sound science literate, but there's very little actual data," she said.



Baker pointed to the first paragraph of the foreword, written by Marita Noon, executive director of Citizens' Alliance for Responsible Energy, a nonprofit and lobbying group that advocates for the use of fossil fuels. In it, Noon writes that Obama's description of climate change as the greatest threat facing mankind is "laughable" at a time when "ISIS is beheading innocent people."

"That as a foreword to something claiming to be scientific is pretty shocking," said Baker.