WATCH: 16-year-old Greta Thunberg rebukes GOPer who thinks other countries must solve climate change

Greta Thunberg, a 16-year-old Swedish climate activist, faced off with members of Congress on Wednesday.

In a hearing before the House Select Committee on the Climate Crisis, Thunberg declined to submit a written opening statement.

"I don’t want you to listen to me, I want you to listen to the scientists and I want you to unite behind the science,” she said.

Republican Rep. Garret Graves of Louisiana tried to make the point that the U.S. should not curb its carbon emissions until other countries agreed to do so.

"Let me ask you a question," Graves said. "If you were sailing across the ocean and you were picking up trash along the way and for every one piece of trash you pick up, there's a boat right next to you dumping out five pieces, how would that make you feel?"

"If you use that logic," Thunberg replied, "I am also dumping a lot of trash in the ocean. I would stop dumping my trash in the ocean and then tell the other boat to stop dumping their trash in the ocean as well."

But it wasn't clear if Graves understood Thunberg's remarks.

"That's the important point here," the lawmaker said. "I think we need to be focusing on the countries that are dumping trash in the ocean. Of course that's a metaphor."

Watch the video below from C-SPAN.