Earth Day is turning 50 today. The awareness campaign that started in 1970 with a push to reduce air pollution and help save endangered species is throwing a massive three-day-long star-studded celebration, although most of the events will be held in quarantine.

Helming the lineup of Earth Day Live 2020 are A-list celebs including Fire Drill Friday co-founder Jane Fonda, recent Academy Award winner Joaquin Phoenix, former vice-president Al Gore, superhero actor Chris Hemsworth, and dozens of other celebrities and musicians.

Organized by climate activists, the event aims to send a message of urgency to the world at large, even if most of us are currently on lockdown. But it also aims to inspire hope.

'A Monumental Time in History'

“This is a monumental time in history,” the organizers wrote on the website. For more ways to get involved, go to Earthday.org. “This moment presents a special opportunity to not only unite our movement around a shared common vision for a better future for humankind but to welcome in organizers, friends, family, and community members who have not been interested in being an active part of the climate movement. The world moves so fast. We may never get another chance like this to bring so many people together to demand a future that works for all of us.”

The three-day live stream event aims to be the largest in climate activism history. It follows a banner year of activism that included strikes and protests to raise awareness and a sense of urgency.

Climate strikes have been made popular by Swedish teen Greta Thunberg. She’s the founder of Fridays for Future, a climate action movement helmed by teens skipping school every Friday in order to protest and demand climate action from world leaders.

“In the midst of a global pandemic, Earth Day Live aims to spur collective action to protect our communities and our planet, through performances, conversations, and training sessions curated by climate activists,” the event’s organizers wrote in a statement.

Fonda, 82, says she’s inspired by Thunberg and other young activists; the Academy Award winner has been arrested numerous times since last year for her climate protests. Joaquin Phoenix has joined Fonda at her protests in DC and LA. He was arrested alongside actor Martin Sheen during a DC protest earlier this year.

Other stars stepped up for specials and activism of their own, including a National Geographic "Born Wild" series where the next generation of animals are celebrated.

For his part, Thor actor Hemsworth appeared on National Geographic's Born Wild Earth Day Special to bring awareness to the plight of baby koala bears still being rehabilitated in the wake of devastating bush fires in his native Australia.

The National Geographic special, hosted by Robin Roberts, celebrates the "next generation" of animals  as a  way of bringing awareness  to climate change. The special  airs on ABC  at 8 p.m. on April 22nd.

The live stream event will feature journalists and climate experts as well as the celeb-led entertainment. It runs April 22-24. More info here.