On Sept. 20, the world likely saw its biggest single-day climate protest in history.
Organizers of the climate strikes estimate that some 4 million people turned up to 6,000 events held in more than 1,000 cities across 185 countries. Quartz attempted its own partial count of the protestors, relying on local sources, and was able to tally at least 1 million people in attendance.
Either figure would eclipse prior protests over climate change, including the People’s Climate March in 2014, which had an estimated 600,000 protestors and the school climate strikes in March this year, which had an estimated 1.4 million in attendance.
As my colleague Michael Coren describes the protests that occurred on Friday:
Organizers of the rallies said their goal is to secure a future for a generation that sees it slipping away. For millions, especially those in the path of extreme weather, global warming is quite literally a matter of life and death. For many others, it is also a matter of what kind of world they and their children will inherit.
Quartz has compiled information from multiple sources to create the most up-to-date crowd estimate. It’s worth noting that, while some of these estimates come from independent sources, most come from organizers themselves. Independent sources may provide different numbers for those rallies.
Below are the crowd sizes we found at climate strikes in 64 cities. You can find the source for each estimate in this spreadsheet.
This story is part of Covering Climate Now, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.