Climate change was a big theme in Time Magazine’s 2021 list of “Most Influential People,” with a handful of climate scientists and environmental advocates making the list along with celebrities like Dolly Parton and Naomi Osaka.

2021 isn’t the first year rock star environmentalists have made Time’s list. Teen activist Greta Thunberg was Time’s “Person of the Year” in 2019. Green New Deal champion Alexandria Ocasio-Cortez was also among the “most influential” that year. This year’s honorees may not be as widely known, but they’ve had a huge impact on how the world grapples with an existential crisis.

Tackling climate change is “possibly the greatest challenge humanity has faced,” one of the people who made the list, Fatih Birol, said in a statement today. Birol heads up the International Energy Agency, which issued a landmark report this year that called for a stop to investments in new fossil fuel infrastructure. It marked a dramatic shift for an institution that started in the 1970s to monitor oil markets.

People around the world are already reeling from back-to-back disasters fueled by climate change: scorching heatwaves, relentless droughts, raging wildfires, and terrifying storms, to name a few.

Researchers had already predicted that these kinds of things would grow worse, but Friederike Otto and Geert Jan van Oldenborgh set out to find climate change’s fingerprints in each catastrophe. They joined forces with other scientists around the world to launch the World Weather Attribution project, which has truly changed the game when it comes to our understanding of how climate change supercharges extreme weather. The group found that this summer’s road-buckling heatwave in the US Pacific Northwest and southwest Canada would have been “virtually impossible” without climate change. Thanks in large part to the group’s work, leading climate scientists can say definitively that human activity is the main driver behind increasingly apocalyptic weather. Otto and van Oldenborgh are on the list.

Time also highlighted a few leaders working on big solutions. Frans Timmermans, executive vice president of the European Commission, was on the list because of his work to get Europe on track to slash heat-trapping greenhouse gas emissions by more than half this decade. That roadmap includes a plan to phase out gas-powered vehicles by 2035.

Then there’s attorney Roger Cox, one of the architects behind Big Oil and Gas’ no good, very bad day in May. Cox won a suit against Royal Dutch Shell to cut its pollution nearly in half by 2030 to keep in line with global goals made in the Paris climate agreement.

As the world charts out potential solutions to the climate crisis, there will need to be watchdogs to ensure that a new energy economy doesn’t repeat the sins of the old one — particularly when it comes to exposing vulnerable communities to toxins and pollution. Phyllis Omido was named one of Time’s “Most Influential People” after she successfully fought to shut down the lead-smelting plant she once worked at in Mombasa, Kenya. Such smelters popped up in Kenya to feed demand for lead-acid batteries paired with solar arrays, and poisoned children in the process — including Omido’s son.

Omido, Cox, Birol, Otto, van Oldenborgh, and Timmermans are just a few of the countless voices around the world holding polluters accountable. So there’s a good chance we’ll see more of their names next year.