Organisations

Here are some national or international-scale solarpunk-adjacent organisations worth working with or donating to.

Environmental activism

Extinction Rebellion (on Sunbeam City @ExtinctionR) - Nonviolent action in response to the urgent threat of climate change. Find a local movement.
Earth Strike (on Sunbeam City @EarthStrikeInt) - The world's first global general strike. Planned for September 27th 2019, it demands immediate action on climate change.
Rising Tide: North America/United Kingdom/Australia/Ecuador/Finland - Occupations and blockades, among other actions, to oppose fossil fuels and protect the environment.
Demand Utopia! - A libertarian municipalist organisation which opposes fascism, takes direct action, and fights for liberation and the environment.
Green Anti-Capitalist Front - An alliance united by a belief that capitalism is one of the core causes of the environmental crisis threatening us all, and that if we do not act soon the costs of that crisis will fall on the poor and powerless.

Transition Network - Neighbourhood-level organising, projects, and development of resources (such as Repair Cafes, community gardens,and makerspaces) to build sustainable circular economies.
Buy Nothing Project - Share your resources and your skills with your neighbours, with the ultimate goal being to buy nothing.
Symbiosis - A network of community organizations across North America, building a democratic and ecological society from the ground up. Symbiosis is fighting for a better world by creating institutions of participatory democracy and the solidarity economy through community organizing, neighborhood by neighborhood, city by city.
Falling Fruit - Plant fruit trees and other edible plants in urban environments to help end food insecurity.
Food Not Lawns - Share skills, labour, and resources to promote urban farming.
Communitere - A non-profit that builds makerspaces and provides other resources to promote independence and resilience in underserved, exploited, or disaster-struck areas.
Project Entropy - An in-development initiative to build a traveling solarpunk makerspace on a boat and develop various open source designs as decided democratically by its community.

Industrial Workers of the World - Join the one big union! Organise your workplace and fight for your rights as a worker. Also facilitates community self-defence, as well as anti-fascism and anti-racism, with the General Defense Committee.
Debt Collective - Dispute your debt, organise debt strikes, and oppose the debt economy.
International Workers Alliance - An international federation of anarcho-syndicalist labour unions and initiatives including the Confederación Nacional del Trabajo and Solidarity Federation.
Anarkismo.net - The product of international co-operation, between platformist organisations and individuals including Zabalaza and the Workers Solidarity Movement, to further communication, discussion and debate within the global anarchist movement.
Anarchist Federation - An international of Anarcho-Synthesist federations.

Food Not Bombs - Collect corporate food waste and prepare meals with and for people in your community. Read their guidebook, Hungry for Peace.
Mutual Aid Disaster Relief - Community-focused aid and reconstruction to areas affected by disasters.
Timebanking: United States/United Kingdom - Trade your time, labor, and skills with your neighbors without exchanging money.
WeHaveRoom - Offer room in your house/on your land to those struck by disasters.
Medic Wiki's list of street medic organisations - Volunteers who provide first aid at protests and actions, and who train others to do the same.

Black Lives Matter - An international grassroots campaign fighting for freedom and justice for all black lives.
Black Socialists of America - A coalition of anticapitalist, internationalist Black Americans who believe in the core principles of socialism as defined by Karl Marx.
Indigenous Anarchist Federation - A group working to unite the unique anarchist struggle of Indigenous people in North America.
Unrepresented Nations and Peoples Organisation (UNPO) - An international membership organisation established to facilitate the voices of unrepresented and marginalised nations and peoples worldwide.