Update: Here's our coverage of the rally.

Across the world, millions of young people are set to “go on strike” Friday to demand quick and bold action on climate change. And here in Boston, organizers estimate 10,000 people from across Massachusetts will participate in a rally at City Hall Plaza and a march to the State House.

Inspired by 16-year-old Swedish activist Greta Thunberg, Friday’s youth-led climate strike is expected to be one of the largest — if not the largest — global environmental demonstrations in history.

There's a lot going on that day, so here’s what you need to know:

Who is organizing this?

Friday's local strike is organized by Massachusetts Climate Strike, a diverse group of young activists, all of whom are under the age of 20. Many leading the strike are affiliated with the Sunrise Movement, the national grassroots organization pushing for progressive climate action and the Green New Deal.

What is happening and where?

10–11:30 a.m.: Community events at City Hall Plaza (art activities, sign-making and partner organization tabling)

11:30 a.m. – 1 p.m.: Main rally at City Hall Plaza with speakers, including:

Gina McCarthy, former U.S. EPA administrator and current director of Harvard C-CHANGE

Saya Ameli Hajebi, Sunrise Movement (17 years old)

Jeremy Ornstein, Sunrise Movement (18 years old)

Ahria Ilyas, Youth-On-Board representative (18 years old)

Michelle Wu, Boston city councilor

The Rev. Mariama White Hammond, Ministry for Ecological Justice

1–1:30 p.m.: March to the State House

1:30–2:30 p.m.: Action at the State House

What do the strikers want?

Organizers have published a list of local and national demands. Here in Massachusetts, they want three things:

for Gov. Charlie Baker to declare a climate emergency; for the Legislature to pass policies that "prioritize workers and communities on the front-lines of poverty and pollution"; and for the state to stop using fossil fuels and building fossil fuel infrastructure, and for all politicians to commit to the No Fossil Fuel Money Pledge.

Nationally, organizers have five demands. Read about them here.

How are schools responding?

School districts throughout the state are responding in various ways.

Boston Public Schools sent a letter to families this week saying, "We believe strongly that regular attendance plays a critical role in our students' academic success. We also believe in the power of young people to affect change on important issues, and that valuable learning can occur through participation in civic activities."

BPS isn't letting kids skip class to attend the rally, but an absence will be considered excused if the student's parent writes a note.

Brookline schools disseminated a similar letter calling the strike a "teachable moment." Schools in the town will designate an area on school grounds for students who want to participate in the rally, however any student who wishes to leave campus will need a note from a parent.

In Fall River, meanwhile, absences related to the strike will not be excused. In an email, superintendent Matthew Malone writes, "Our policy allows for waived absences against our mandatory attendance policy for [doctors] appointments, college visits, etc. I’m not going to suspend anyone for skipping school in the 20th, but the absence is not excused."

Last week, the international organization Health Care Without Harm issued a symbolic medical excuse note to demonstrate solidarity with students who are striking. It has more than 675 signatures — 100 of those from Massachusetts.

This story is part of "Covering Climate Now," a week-long global initiative of over 250 news outlets.