A pro-climate change protester interrupted President Obama's speech on manmade climate change Wednesday, prompting Obama to complain that he was being interrupted.

"I gotcha. Okay. I got you. Thank you. That's a great banner," the president said, trying to appease a young woman chanting from a crowd. The protest brought his comments at the Lake Tahoe Summit in Nevada to a full stop for a few moments, and also raised Obama's hackles a bit.

"I'm about to talk about it though," Obama said to the protesters, who were trying to shout over him. "So, you're interrupting me."

Climate activists have been protesting the administration for moving forward with oil and gas leases, despite the president's many regulations and support for an international treaty to stop global warming.

"I was going to talk about climate change and why it's so important," the president said once they began to quiet down. It wasn't clear if security was called to usher them out.

Once he got back to making his point, he said it isn't hearsay that climate change is occurring and that it is manmade.

"The fact is, it is manmade. It's not 'we think it's manmade.' It's not 'we guess it's manmade.' It's not 'a lot of people are saying it's manmade.' It's not, 'I'm not a scientist so I don't know.'"

"You don't have to be a scientist," Obama said. "You have to read, or listen to scientists to know that the overwhelming body of scientific evidence shows us that climate change is caused by human activity."

He said that his administration has done more to combat climate change than any other in history.

"And appropos of that young lady's sign, we've been working on climate change on every front," he said. "We worked to generate more clean energy, use less dirty energy, waste less energy overall."