MADISON, Wis. — Wisconsin Gov. Scott Walker is scheduled to speak at a prominent think tank that denies the existence of man-made global warming.

Walker was scheduled to appear at a $250 dinner and reception Wednesday night at the Chicago-based Heartland Institute. The group's website describes Walker as "the country's most successful and important governor."

He was scheduled to speak last year at Heartland's 28th anniversary but had to cancel when his wife, Tonette, had an emergency appendectomy.

Heartland bills itself as discovering, developing, and promoting free-market solutions to social and economic issues.

Walker has been traveling the country speaking at events hosted by Republicans and conservatives, fueling speculation that he's going to run for president in 2016.