💭 The Most Important Decision of Your Life

“Whatever you can do, or dream you can, begin it. Boldness has genius, power, and magic in it.” — Goethe

Dear friend,

I’m writing to you about the most critical matter in humanity's history: what will happen to the world’s climate over the next two decades, and what we must do about it.

Now, I’ll be honest: when I say this is the most critical matter in human history, a voice in your head might not quite believe it. I’ll admit — I hear that voice too. We only honestly believe what’s in front of our noses. But on a deeper level, we believe it — because somewhere inside us, we know it’s true. We know we’re facing the end of humanity because we are.

I’ve given around 200 public talks on the climate crisis. I often begin by talking about cancer. When you’re told you might have cancer, you experience this inner split — disbelief alongside a desperate need to know the truth. What do you ask first? You ask for the number — the likelihood. I recently had this experience myself. I was told I might have cancer. Without hesitation, I asked the question: what’s the number? In my case, it was 3%. I now need to undergo tests. Fingers crossed I’ll be okay.

In 2018, when I helped found Extinction Rebellion, it took off because of one number: 12. We had twelve years left. According to a major UN report, emissions had to halve by 2030, or it would be “too late.” Millions of children and adults took to the streets. But now, seven years later, the numbers are a hundred times worse.

We’ve already passed 1.5°C. The underlying temperature has risen by 0.2°C in just one year. We’re now told it’s increasing by 0.4°C per decade. That puts us at 2°C by 2030. The Paris Agreement is dead. It is now going to happen.

I recently spent a day compiling all the latest data from official science reports: the locked-in warming due to air pollution removal and carbon lag; additional heating from collapsing carbon sinks; the exponential rise in wildfires and methane emissions from permafrost. Put it all together, and the result is clear—we’re on track to exceed 5°C by around 2060. Without drastic change, our young people will face the extinction of humanity by the time they reach middle age, which will result in billions of deaths.

That’s why this is the most critical matter in human history.

You can read the briefing on the science behind our coming extinction. It’s now under review by scientists around the world. Don’t be surprised if, over the coming year, official bodies begin releasing analyses that echo these conclusions. A recent report by the British insurance industry has already predicted four billion deaths. At some point soon, when large-scale crisis events hit, there will be an almighty explosion of public mobilisation — like Extinction Rebellion, but many, many times bigger.

This is why I’m writing to you.

I’m asking you to leave your job — your university course, your current occupation — and commit full-time to Rev21 (Revolution in the 21st Century). I’m writing not only because of the dire situation we face, but because I genuinely believe we now have the opportunity to help create this new international mobilisation.

If you’re going to commit to a full-time project in this moment, you’ll want to know it has the maximum possible leverage to save what can still be saved. So this isn’t a request to join a single action, or support a specific campaign — I’m asking you to help build the organisation that creates the campaigns. That trains, seeds and supports a global movement to remake the world. Because that is what is needed.

Rev21, after a year of development — in close collaboration with other networks — is now ready to do this.

We are launching six key interconnected projects:

1. Global Festival of Resistance – Coordinating mass events on the same dates each year across the world to unify our movements.
2. Fundraising – Raising and distributing funds to grassroots campaigns that participate in the festivals and initiate mass public action.
3. Local Assemblies – Organising deliberative assemblies that articulate demands and provide legitimacy to people power.
4. Movement Parties – Supporting new political platforms to contest local and national elections and counter the rise of the far right.
5. Leadership Training – Delivering in-depth courses to equip organisers with the skills to lead powerful campaigns.
6. International Conventions – Hosting twice-yearly gatherings of top movement figures to share knowledge, strategy, and inspiration.

These initiatives only work if they happen together. The whole is far greater than the sum of the parts. As we connect with movements around the world working towards nonviolent system change, we will coordinate closely, offering hope and a clear pathway towards a livable future — a democratic alternative to collapse and fascism.

This is the plan. And we know we can do it.

Robin Boardman and I helped organise the mobilisation of 200,000 people for Extinction Rebellion in the UK. The teams I’ve worked with have created some of the biggest climate campaigns in the Western world. We’ve done this before. Now, with the election of Trump and increasing geopolitical instability, major funders are actively looking to finance systemic alternatives. I was in a meeting last year where the vision laid out in this letter was presented — and one funder indicated he could provide up to $5 million. We’ve just presented to a major global company and a personal letter is now on its way to the founder, who is looking to donate millions of euros.

What’s missing is you — and others like you — to build the teams that make this vision real.

You don’t need special skills. But you do need serious commitment — to match the seriousness of what we face. This is about creating a new world out of the one that is dying around us.

Last year, The New Statesman named me one of the 50 most influential progressives in the UK—the only environmentalist ranked higher than me was David Attenborough. I was named one of the 50 most influential progressives in the UK not because I make nature documentaries but because I help make change happen—or, more accurately, I work with teams that make change happen.

And I want you to be part of one of those teams.

Yes, this is a long letter. Marketing experts would say it’s too long. That people have short attention spans. That I should keep it snappy. I couldn’t disagree more. If you’re going to make a serious commitment, you deserve to see the full picture. To know that the ask is credible.

If you’ve made it this far, then you’re serious.

The next step is simple: join one of the Induction Zoom calls on the third Sunday of the month, ask your questions, and then make a decision. It might take time to make the transition. You might only be able to start part-time. That’s absolutely fine. Come along to the Zoom and we can talk it through.

This is a massive opportunity: to be part of the next great mobilisation. To give your life to the common good — at the edge of history.

It is what it is.

I look forward to working with you.

With best wishes,
Roger Hallam
Co-founder, Rev21

P.S. One last thing — please share this letter with three people you know who might be ready for this journey. And ask them to share it with three more. Thank you.

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