Four former EPA administrators testified before the Senate Environment and Public Works Subcommittee on Clean Air and Nuclear Safety that more climate change action needs to be taken now.

Obviously, substantial action has been taken, it just hasn't been by the government. CO2 emissions from energy are back at early 1990s levels, which means so is overall CO2. Coal, the biggest polluter that America was forced to rely on when the Clinton administration banned nuclear energy in 1994, now has early 1980s levels of emissions.

But that is all due to the private sector using more natural gas and a moribund economy. So the subcommittee wanted to focus on the new restrictions leveled by the EPA outside Congress and why they were needed when emissions are dropping without job-killing provisions.

The former EPA administrators of Richard Nixon, Ronald Reagan, George H.W. Bush and George W. Bush disagreed that nothing needs to be done and that the EPA did not have the legal authority to do it. They also dispel the myth that Republicans are uniformly against climate science the way Democrats are against GMOs, vaccines and energy.

"There are a lot of Republicans that believe that the climate is changing and that humans play a role in that," said Christine Todd Whitman, EPA administrator for George W. Bush. "They just need some cover."

In opposition to the Republicans seeking action on climate change was a biologist, an economist and a state Attorney General.

Read more: Republican Former EPA Chiefs Try To Convince Senate GOP That Climate Change Is Real by Kate Sheppard, Huffington Post