Bill Nye, beloved host of the television show "Bill Nye the Science Guy," surprised Democratic Rep. Alexandria Ocasio-Cortez while she spoke at the South by Southwest (SXSW) festival Saturday night in Austin. He asked her a question about the impact of fear in stemming progressive issues, such as climate change.

After the New York lawmaker was told the following question would be her last, viewers can hear her scream, "Oh my gosh," as Nye appeared at a microphone, in a video posted by TicToc by Bloomberg. After the television personality jokingly told the audience, "I can't take selfies with everyone," he asked Ocasio-Cortez if she had a plan to work with those whose fear prevents them from supporting progressive issues.

"People are just afraid of what will happen if we try to make these big changes," Nye said. "When we address climate change, we're going to have clean water, access to the internet and renewable electricity for everyone on Earth."

The freshman congresswoman responded to Nye's question after applause from the shocked audience died down — and she finished a brief chant of "Bill! Bill! Bill!" She spoke about dismantling fear and urged people to speak out about the issues they believe in. She finished her answer stating, "Courage begets courage. So, the first person who stands up has to encounter the most amount of fear and discomfort, but once that one person stands up, it becomes immensely easier for the second person and the third."

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After the surprise, the pair posed for a selfie together and Nye tweeted his support of the representative. "AOC gets it," he tweeted Saturday night. "She sees that fear is dividing us. We can address income inequality. We can address climate change, if we get together and get to work."

AOC gets it. She sees that fear is dividing us. We can address income inequality. We can address climate change, if we get together and get to work. #SXSW @AOC pic.twitter.com/I8tSbAc97u — Bill Nye (@BillNye) March 10, 2019

Ocasio-Cortez introduced the "Green New Deal" with Massachusetts Democrat Sen. Ed Markey in February. The initiative's goal is to convert the entire U.S. economy to renewable energy within 12 years, while also sparking a massive burst of job-creation and technological innovation. Nye has been a longtime advocate for science and the importance of tackling the issue of climate change.

The lawmaker also spoke about a wide range of issues during her talk, including capitalism and political moderates.