Before the COVID-19 pandemic hit, more than 6 million people flooded into the streets in 2019 as part of mass Fridays for Future protests, aiming to force governments and companies to act more swiftly to slash emissions and curb climate change.

But while the protests boosted public awareness of climate threats, the response from institutions was largely reports, letters and "creative accounting," said German activist Luisa Neubauer, who along with Sweden's Greta Thunberg helped organize the strikes.

"They're trying to blind us with the nice words and promises, and prevent us from looking into the details and (calling) them out," the 26-year-old said.