The science is overwhelming. Climate change is real and poses a grave threat to human life on Earth. We need to keep average global temperature rise below a livable 2-degrees centigrade.

So why the persistent doubt and uncertainty? Primarily because of disinformation by 100 energy companies responsible for 71 percent of the world's industrial greenhouse gas emissions. They seem to believe there are only two contrary choices: doing the right thing for humankind or making massive profits, and they've chosen profits.

Many psychologists suggest these companies exhibit the characteristics of a psychopath: They lack empathy, guilt, and remorse. They pretend to be good but act the opposite. Alex Steffen, an environmental writer, has coined the term "predatory delay" to describe this aberrant behavior.

The misinformation poster child is Exxon. Back in 1977, James F. Black, one of Exxon's senior scientists, informed the company's top leaders, "There is general scientific agreement that the most likely manner in which mankind is influencing the global climate is through carbon-dioxide release from the burning of fossil fuels."

During 40 years of knowing the truth about climate change Exxon issued an internal memo recommending the company "emphasize the uncertainty" in the scientific data, another document declared that "victory will be achieved" when average citizens and the media "recognize uncertainties in climate science" to be "conventional wisdom," and it spent more than $33 million supporting organizations that questioned the scientific consensus on global warming.

This helps explain why 2017 polls still found that almost 90 percent of Americans did not believe there was a scientific consensus on global warming. Exxon and other energy companies systematically have compromised the global struggle to adequately reduce greenhouse-gas emissions. Government here and abroad needs to confront this predatory delay and force Exxon to do the right thing.

Tim Scherkenbach

Warba, Minn.