In the race against time that is the worldwide effort to avoid the worst of climate change, there’s a lot to despair. Sometimes it seems every day brings more bad news about the seeming inevitability of global heating, food shortages and chaotic mass migrations.
But for today, let’s look on the bright side. 
A week of walkouts, rallies and other public events begins this Friday, Sept. 20, with the global climate strike. It will be the biggest-ever day of climate action. 
If there is a day when we can begin to turn things around toward a safer and more stable world, it would be a good idea for it to be now.
You want hope? Even for those not versed in the grim physics of climate emergency, one person stands out as a beacon. 
Greta Thunberg. She’s the girl who recently came to America on a zero-emission sailboat powered by solar panels and underwater turbines.
Thunberg, age 16, was once a lonely voice of seeming unreason when she refused to go to school and sat alone on the steps of the Swedish Parliament — a one-girl climate strike. But this coming Monday at the UN, she will stand in her characteristic braids and speak to the world in her lovely English-inflected accent.
Her simple act of not going to school on Fridays inspired a youth movement of school strikes and now worldwide walkouts. 
One power of the youth climate movement is its plea to adults — who hold the future in their hands — that we act immediately.
Greta doesn’t mince words: “You say you love your children above all else and yet you are stealing their future in front of their very eyes.”
“Since our leaders are behaving like children, we will have to take the responsibility they should have taken long ago,” she told leaders at the climate summit in Poland.
Amid the blur of statistics about climate change, there’s one number that stands out as the most hopeful.
New research indicates that if just 3.5 percent of a population participates in public events that call for societal change, those campaigns will succeed. The world belongs to those who show up. It’s called the 3.5 percent Rule.
Harvard political scientist Erica Chenoweth looked at hundreds of protest movements in recent decades. General strikes were the best at bringing about change. 
But many other forms of protest have proved effective. Massive street rallies brought down repressive regimes in the Philippines, Algeria and Estonia. The Velvet Revolution transformed communist Czechoslovakia. Divestment from noxious industries (fossil fuels) and nations (apartheid South Africa) has proven powerful, as have plain old consumer boycotts.
BBC Future reports that Chenoweth is now looking at Extinction Rebellion and other groups like 350.org, which was founded here in Vermont. “They are up against a lot of inertia,” BBC reports her saying. “But I think that they have an incredibly thoughtful and strategic core. And they seem to have all the right instincts about how to develop and teach through nonviolent resistance campaigns.” 
It’s not easy to reach the point where 3.5 percent of a population gets active. But there’s hope in this: So far as Chenoweth can tell from studying hundreds of movements, the 3.5 percent Rule guarantees success.
But as the BBC notes, “Raising even that level of support is no mean feat. In the U.K. it would amount to 2.3 million people actively engaging in a movement … In the U.S., it would involve 11 million citizens.”
That’s a lot of people. But local actions matter. By essentially blockading London, the Extinction Rebellion forced Parliament to declare that the nation is in a climate emergency. 
More evidence for local: Back in 2006, about a thousand Vermonters gathered in Burlington at what was then the largest-ever rally held about global warming.
Just eight years later there were over 400,000 in the streets of New York for the People’s Climate March. Another 250,000 encircled the White House in 2017, joined by hundreds of thousands in other U.S. cities. The numbers grow with every global day of actions. 
In the next week there will be climate events all over Vermont that will likely involve several thousand Vermonters of all ages. It’s a cornucopia of citizen activism and, yes, fun. Among events listed at vermontclimatestrike.org:
Teach-ins, die-ins, sing-ins, art projects, musical performances, dances, bike rallies, worship services, electric vehicle events, bannering, films, nature walks, tree plantings, regenerative agriculture, action against fossil-fuel lobbyists and nonviolent direct action at the largest remaining coal plant in New England.
Towns and cities hosting events range from Newport to Brattleboro, from Barre to Worcester.
The media have taken notice, too. Teen Voguewas proud to make Thunberg “a cover star.” Ripton’s own Bill McKibben has the cover story in this week’s Timemagazine, in a rare issue devoted entirely to climate change.
Another sign of progress: Vermont businesses including Burton Snowboards, SunCommon and Ben & Jerry’s have joined in, with Seventh Generation donating a week’s worth of advertising to emphasize the climate crisis.
“I’m striking because I want the corrupt corporations that are responsible for this climate crisis to fear our collective power,” says Divya Gudur, a Middlebury College student. “I want them to know that they are being held accountable, and that they, along with the politicians, will have to listen to what we have to say.” 
Gregory Dennis’s column appears here every other Thursday and is archived on his blog at www.gregdennis.wordpress.com. Email: [email protected]. Twitter: @greengregdennis.