The University of Iowa's Center for Global, Regional and Environmental Research has been studying climate change in Iowa and around the world for 25 years this year.
Greg Carmichael, co-director of the center and professor of chemical and biochemical engineering at the University of Iowa, says public opinion has come a long way since the center's founding and that climate change deniers are "dead wrong" about the facts.
"The relationship between humans and climate change and the human role is at the same level of confidence as the connection between tobacco smoke and health outcomes," Carmichael explains.
During this River to River program, host Ben Kieffer talks with Carmichael and Jerry Schnoor, also co-director of the center. Schnoor says that while natural causes could be causing some of the global warming we're tracking, that's a very small part of the picture.
"You shouldn't take comfort in the fact that there have been natural changes in the past. We know for a fact that the greenhouses gases that we are admitting from burning our natural gas and fossil fuels causes a blanket effect to warm the earth," Schoor says. "Any natural causes that we aren't fully aware of or don't have evidence for ... we're simply adding to those. You should take action because we are adding to any natural warming, and the amount we're adding is quite substantial."