Primate researcher Goodall and "Star Trek" actor Shatner, both renowned activists, will be recognized at a star-studded Los Angeles fundraising gala on April 2 which aims to spotlight environmental concerns at a critical moment.

"We do not have the luxury of waiting for action on climate change and environmental justice as communities grapple with the crisis on a daily basis. The choices we make today will shape the future of our planet and our communities," Ben Jealous, executive director of the Sierra Club, told AFP.

US President Donald Trump, who has called climate change a "scam," recently pulled Washington out of the landmark Paris Agreement for a second time, expanded domestic oil drilling, and signed executive orders to slow the transition to electric vehicles.

Government agencies including the Environmental Protection Agency and the National Oceanic and Atmospheric Administration have been targeted for mass layoffs.

Goodall will receive the Sierra Club Lifetime Achievement Award "for her inspiring dedication to protect chimpanzees and conserving the natural world."

Shatner will collect a Visionary Award "for using his platform to raise awareness about the climate crisis."

Other honorees at the 2025 Trail Blazers Ball, which brings activists and environmentalists together with celebrities, include Indigenous climate activist and fashion model Quannah Chasinghorse.

The Sierra Club boasts millions of members and supporters, and is the oldest US environmental group -- formed in 1892.

Most scientists agree that climate change currently underway differs from natural cycles of the past.

The Intergovernmental Panel on Climate Change says it is indisputably attributable to human activity, and in particular to the burning of fossil fuels, especially since the end of the 19th century.