President Barack Obama is teaming up with actor Leonardo DiCaprio to push for action on climate change.
The two appeared together Monday on the White House South Lawn as part of a festival of technology and music meant to re-create the spirit of the annual South by Southwest festival in Austin, Texas.
Obama said the world is in "a race against time" to combat climate change, but the good news is that "there's still time to pass the test" and make real progress on the issue.
DeCaprio, joined by climate scientist Dr. Katharine Hayhoe, told the White House crowd that the scientific consensus about the dangers of climate change is in, and "the argument is now over."
The actor said anyone who doesn't believe that "should not be allowed to hold public office."
"South by South Lawn," or SXSL, rolled out on Monday, bringing together artists, innovators, musicians and entrepreneurs for the equivalent of a giant White House block party for tech nerds.
The president made a midday visit to the South Lawn to check out booths and vendors promoting everything from virtual reality technology to fake tattoos.
In an email promoting the event, Obama wrote that SXSL was "at its heart, a call to action. The folks out on the lawn today are artists, creators, entrepreneurs, and innovators who will share how they've used their unique skills to engage their communities in making the change they want to see -- whether it's curing cancer, fighting poverty, empowering women, and so much more."
DiCaprio's documentary film on climate change, "Before the Flood," got its domestic premier on the lawn later in the day.
Tech blogger and entrepreneur Anil Dash said the South Lawn event was a way to connect the dots between SXSW, with its ideas for changing the world, and the people who are "doing the actual work" to use technology to improve worker rights, civil rights and more. Panel discussions included topics such as "feeding the future" and "fixing real problems."
The White House tech fest also featured a student film festival, a wall of art made of Post-Its, Lego statues, demonstrations on the science of food and using technology to help the disabled and lots of music. Among those performing: the Lumineers, Gallant, Black Alley, Sharon Jones & The Dap-Kings and DJ Bev Bond.