One of President-elect Trump’s most controversial nominees is Scott Pruitt, the Oklahoma attorney general tapped to head the Environmental Protection Agency — an agency he has sued repeatedly. Pruitt is also on record asserting that there is a “debate” about climate change — meaning it was virtually certain that one or more senators would challenge him on the matter.

Still, the exchange between Sen. Bernie Sanders and Pruitt from earlier Wednesday was pretty intense, with Pruitt seeking to defend the view that humans may contribute to climate change “in some manner,” and Sanders insisting that the science says a great deal more than that.

At one point in the exchange, Sanders simply asked Pruitt, “Why is the climate changing?” “I’m asking you a personal opinion,” he continued.

“My personal opinion is immaterial to the job of the…” Pruitt began.

“Really? You are going to be the head of the agency to protect the environment, and your personal feelings about whether climate change is caused by human activity and carbon emissions is immaterial?” Sanders retorted.

You can watch it in the video below, or read it in the transcript pasted after that.

Sen. Bernie Sanders (I-Vt.) and Scott Pruitt, President-elect Donald Trump's nominee for Environmental Protection Agency administrator, clash at Pruitt's confirmation hearing. (Reuters)

Here’s the full exchange between Sanders and Pruitt:

Sanders: My office has received a great deal of comments from people in the state of Vermont, which takes environmental protection very seriously, as well as from all over the country. And the fear is that the nomination of Mr. Pruitt is a nomination designed to protect the fossil fuel industry and not the environment. I would like to ask Mr. Pruitt a question. As I understand it, earlier in this hearing, you said that Mr. Trump was wrong in suggesting, in stating over and over again, that climate change was a quote unquote “hoax.” Is that in fact the case?

Pruitt: That is correct Senator.

Sanders: Okay. Let me ask you this. As you may know, some 97 percent of scientists who have written articles for peer reviewed journals have concluded that climate change is real, it is caused by human activity, and it is already causing devastating problems in our country and around the world. Do you believe that climate change is caused by the emission, by carbon emissions? By human activity?

Pruitt: Senator, as I indicated, you weren’t here during my opening statement, but as I indicated in my opening statement, the climate is changing, and human activity contributes to that in some manner.

Sanders: In some manner?

Pruitt: Yes, sir.

Sanders: 97 percent of the scientists who wrote articles in peer reviewed journals believe that human activity is the fundamental reason we are seeing climate change. You disagree with that?

Pruitt: I believe the ability to measure, with precision, the degree of human activity’s impact on the climate is subject to more debate on whether the climate is changing or whether human activity contributes to it.

Sanders: While you are not certain, the vast majority of scientists are telling us that if we do not get our act together and transform our energy system away from fossil fuel, there is a real question as to the quality of the planet that we are going to be leaving our children and our grandchildren. So you are applying for a job as administrator for the EPA, to protect our environment, overwhelming majority of scientists say we have got to act boldly, and you’re telling me that there needs to be more debate on this issue and that we should not be acting boldly?

Pruitt: No, Senator, as I’ve indicated, the climate is changing, and human activity impacts that…

Sanders: But you haven’t told me why you think the climate is changing.

Pruitt: Well Senator, the job of the administrator is to carry out the statutes as passed by this body…

Sanders: Why is the climate changing?

Pruitt: Senator, in response to the CO2 issue, the EPA administration is constrained by statutes…

Sanders: I’m asking you a personal opinion.

Pruitt: My personal opinion is immaterial to the job of the…

Sanders: Really? You are going to be the head of the agency to protect the environment, and your personal feelings about whether climate change is caused by human activity and carbon emissions is immaterial?

Pruitt: Senator, I’ve acknowledged to you that human activity impacts…

Sanders: Impacts. The scientific community doesn’t tell us it impacts, they say it is the cause of climate change. We have to transform our energy system. Do you believe we have to transform our energy system in order to protect the planet for future generations?

Pruitt: I believe the EPA has a very important role at regulating the emission of CO2.

Sanders: You didn’t answer my question. Do you believe we have to transform our energy system away from fossil fuel to do what the scientific community is telling us in order to make sure that this planet is healthy for our children and grandchildren?

Pruitt: Senator, I believe that the administrator has a very important role to perform in regulating CO2.

Sanders: Can you tell me, as I think all of us know, Oklahoma has been subjected to a record breaking number of earthquakes. Scientists in Oklahoma, scientists say that Oklahoma is almost certain to have more earthquakes with heightened risk of a large quake, probable to endure for a decade, and that the cause of this is fracking. Can you point me, picking up on Senator Harris’s discussion with you, can you point me to any opinion that you wrote, any enforcement actions that you took against the companies that were injecting waste fracking water?

Pruitt: Senator, let me say I’m very concerned about the connection between activity in Oklahoma…

Sanders: And therefore you must have taken action. I guess, can you tell me who you fined for doing this?    

Pruitt: The corporation commission in Oklahoma is vested with the jurisdiction and they have actually acted on that…

Sanders: And you have made public statements expressing your deep concern about this?  

Pruitt: We have worked with…

Sanders: You have made public statements? You’re in a state which is seeing a record breaking number of earthquakes, you’re the attorney general. Obviously you have stood up and said you will do everything you can to stop future earthquakes as a result of fracking?

Pruitt: Senator, I’ve acknowledged that I’m concern…

Sanders: You’ve acknowledged you’re concerned. Your state is having a record number of, well if that’s the kind of administrator for the EPA, your state’s having a record breaking number of earthquakes, you have not acknowledged your concern. If that’s the kind of EPA administrator you will be, you’re not going to get my vote.