By H. Sterling Burnett

President Obama is hostile to open debate and research that contradicts his opinions and policies.

The most recent evidence of this came last month, when Attorney General Loretta Lynch gave testimony before the Senate Judiciary Committee and said the Department of Justice has discussed pursuing legal action against companies, research institutions, and scientists who debate whether humans are causing catastrophic climate change.

The revelation that the Obama administration has asked the FBI to investigate people involved in an ongoing scientific debate should shock the sensibilities of all Americans.

It was not Obama or Lynch who first broached the idea of prosecuting climate realists for exercising their free-speech rights; that dishonor falls to Sen. Sheldon Whitehouse (D., R.I.), who in a May Washington Post op-ed argued that the fossil-fuel industry is collaborating with conservative think tanks to disseminate research contradicting the scientific consensus on man-caused climate change.

The First Amendment presents the first significant hurdle for efforts by Whitehouse and the Obama administration to silence their critics. For more than 200 years, the First Amendment has protected the rights of individuals and groups to speak freely on issues of public importance, including global climate change - even if politically connected renewable-power interests, influential environmentalists, members of Congress, or even the president of the United States disagrees with them.

Another problem hampering the attempt to prosecute climate skeptics is that the truth is a legal defense against fraud charges, which means it is impossible for Lynch to prove that skeptical scientists and climate researchers are lying when they say the human impact on climate is unclear and evidence of harm is lacking. Contrary to the constant false claims made by the Obama administration, the matter is still part of an ongoing, lively scientific debate.

The German climate science site No Tricks Zone documented about 250 peer-reviewed academic articles published in 2015 disputing one or more of the many claims made by climate-change alarmists.

These papers show that nature plays a significant role in climate change, increasing amounts of carbon dioxide are improving plant growth, and, contrary to climate model projections, weather extremes are not getting worse due to climate change. These articles make it clear, individually and collectively, that the discussion concerning the causes and consequences of climate change is not over.

Additionally, a survey of members of the American Meteorological Society found that 67 percent believe humans are responsible for more than half of climate change. Are we to believe that the 33 percent of members who disagree that humans are responsible for climate change are committing fraud?

For centuries people believed illnesses were due to an imbalance of humors in the body and that Earth was flat and was the center of the universe. Those people were wrong, but most of them were not frauds.

Everyone who disputes that humans are causing dangerous climate change could be completely wrong and may be shown to be so as more evidence is gathered and carefully analyzed. It's also possible that those who believe fossil-fuel use is causing a climate apocalypse are wrong. But being wrong does not constitute fraud. Debate is the scientific method in action, not a crime.

By raising the specter of possible prosecution, the Obama administration is attempting to silence those who disagree with it on climate matters. This vile effort threatens to undermine free speech and open inquiry, the very underpinnings of successful democracies and the scientific method.

H. Sterling Burnett is a research fellow on energy and the environment at the Heartland Institute.