The science around climate change hasn't proven that carbon dioxide is the primary contributor to temperature fluctuations on Earth, Southern Company Chairman and CEO Tom Fanning told CNBC on Tuesday.
Fanning said on "Squawk Box" he's not denying that climate change is occurring. He just doesn't believe the evidence proves that the release of carbon dioxide gas, or CO2, is the main culprit.
"Is climate change happening? Certainly. It's been happening for millennia," said Fanning, who leads a $49 billion energy giant that brings electricity and natural gas to 9 million customers.
Earlier this month on CNBC, new EPA Administrator Scott Pruitt described a view similar to Fanning's concerning CO2, while calling for more study.
"I think that measuring with precision human activity on the climate is something very challenging to do, and there's tremendous disagreement about the degree of impact, so no, I would not agree that it's a primary contributor to the global warming that we see," Pruitt told "Squawk Box" on March 9.
But the EPA's website tells a different story. The "Causes of Climate Change" section states "carbon dioxide is the primary greenhouse gas that is contributing to recent climate change."
"Human activities, such as the burning of fossil fuels and changes in land use, release large amounts of CO2, causing concentrations in the atmosphere to rise," the EPA website adds.
Speaking ahead of President Donald Trump's executive orders aimed at rolling back Obama-era regulations to combat climate change, Fanning said he's encouraged by the new administration's approach.
"The biggest deal will be restoring balance between federal overreach in regulation and letting regulators set policy, rather than letting set policy Congress," he said.