Rick Perry's confirmation hearing is today. He may not have known what he signed up for.

UPDATE 9:01 a.m. EST:

Parts of Rick Perry's testimony he will deliver before the Senate addresses his infamous declaration that he would shut down the Department of Energy. 

"After being briefed on so many of the vital functions of the Department of Energy, I regret recommending its elimination," the testimony reads. 

He also wrote, "I believe the climate is changing...some of it is naturally occurring, but some of it is also caused by man-made activity." In 2010, he called global warming "hysteria."

Rick Perry's Cabinet confirmation hearing is set for 10 a.m. Thursday. He's Donald Trump's pick to run the Department of Energy.

But a New York Times report suggests he didn't exactly know what he was getting into. Perry reportedly planned to be an "advocate for energy" but didn't know the department also maintained the U.S. nuclear arsenal. 

In fact, about two-thirds of the department's $30 billion yearly budget is devoted to nuclear weapons one way or another.

This quickly drew a lot of criticism.

Many pointed to Perry's predecessors.

But Perry supporters say this isn't a big deal.

"If you asked him now, he'd say, 'I'm serious about the challenges facing the nuclear complex.' It's been a learning curve," said Republican energy lobbyist Michael McKenna. 

As governor of Texas, Perry led a plan to create a nuclear waste dump in his state, which no other governor has done.

"He really understands this stuff," said Charles McDonald, spokesman for the company Perry hired to run the dump, Waste Control Specialists.

WATCH | Perry also infamously forgot the name of the Department of Energy in 2011 while running for the Republican nomination for president. He originally promised he'd shut down the agency if elected. 

Critics claim his background doesn't make him fit to run the Department of Energy.