3.5 %

Bill McKibben,
Author, educator, environmentalist, and co-founder of 350.org

This totemic number comes from the work of Harvard political scientist Erica Chenoweth, whose global database of nonviolent social protests finds that when that percentage of citizens engage in a peaceful civil uprising, they are nearly certain to win. (She also finds that nonviolent resistance is twice as successful as the use of force.)

There are 8 billion people on the planet; that would imply the climate crisis requires a movement of 280 million people, which is a lot of human beings, but easier to imagine than, say, 50%.

In a sense, the rule recognizes that most people most of the time will be apathetic and uninvolved, which makes it hard to mount an uprising, but also hard to stop one once it gets started, especially if there's no violence to repulse bystanders.

Historians, Chenoweth notes, have tended to fixate on violent upheavals, and so have the movies--but “ordinary people, all the time, are engaging in pretty heroic activities that are actually changing the way the world – and those deserve some notice and celebration as well.”

(1) Mark Engler, This Is An Uprising

(2) Gahndi (1982)

(3) Waging Nonviolence