After denying the existence of climate change for years, a handful of elected Republicans now acknowledge that human activity is the primary cause and are calling for “innovative” action to address it.

In 2011, Republican presidential candidate Mitt Romney staked out no fewer than four different positions on climate change, at one point telling a Pennsylvania voter, “We don’t know what’s causing climate change on this planet.” By mid-2018, Romney was calling for federal action to curb climate change.

Before heading the House Republican conference for six years, Rep. Cathy McMorris Rodgers (R-Wash.) called the science around human activity and climate change “inconclusive at best.” Now she says human activity is at least “partially” responsible.

Sen. Pat Roberts (R-Kan.) called climate change science “condescending elitism” in 2010. Now, Roberts not only acknowledges the science, but he also says humans contribute to climate change.

And in 2011, Rep. Fred Upton (R-Mich.), then-chairman of the committee with jurisdiction over the Environmental Protection Agency, said climate change was not “man-made.” Now he says climate change is real and must be addressed, while not explicitly acknowledging its cause.

That Republicans are publicly discussing ways to combat climate change is remarkable, considering that 49 of 54 Republican senators voted against attributing climate change to human activity just four years ago. The science of the causes and effects of climate change has not changed significantly over the past decade. What has changed is the politics of climate change, as the video above illustrates.

Three years ago, 49 percent of Republicans believed in climate change. Today, 64 percent do.

A record 45 percent of Americans now believe immediate action is needed to combat climate change, including 15 percent of Republicans, according to a December Wall Street Journal-NBC News poll. In 2010, fewer than 10 percent of Republicans thought immediate action was needed to combat climate change.

Today, fossil fuel companies are curbing greenhouse gas emissions or calling for action to combat climate change (“All the climate arguments are real, urgent and important,” BP’s chief economist recently told The Washington Post).

And Democrats have seized on an issue largely skirted by Republicans over the past decade with proposals including the nonbinding Green New Deal, which has led to a flurry of alternatives, many offered by Republicans.

A growing number of Republicans now no longer contest the science behind human-caused climate change, including Senate Majority Leader Mitch McConnell (R-Ky.), who told reporters last week that he believed human activity is causing the climate to change, a far cry from when he would not even acknowledge the existence of the science in 2014.

“I’m not a scientist,” McConnell told the Cincinnati Enquirer at the time. “I’m interested in protecting Kentucky’s economy.”

Scott Clement contributed to this report.