Someone said something really striking to me the other day – that weather used to be the last thing on the news, but now it’s the first. And it’s not good news. Fire, floods, drought – climate change in terrible and obvious action. It made me think of something I’ve been increasingly obsessed by – unexpectedly – which is pensions. Pensions used to be the last thing on our minds, certainly not something to talk about at lunch, but to help tackle the climate crisis, they actually should now be the first.

With delegates from across the world gathering in Glasgow this November for Cop26 – the most important climate negotiations for a generation – pensions should be right at the heart of the conversation. They can be a huge and radical agent for change: a powerful weapon in our armoury for the battle against the climate crisis.

Over the past 18 months, I’ve been part of the Make My Money Matter campaign, a partnership of the public, businesses and financial institutions that’s pushing to make sure that the trillions of pounds – yes, trillions – that are invested through our pension funds help tackle the climate crisis, not fuel the fire. With GBP2.6tn invested in UK pensions alone, and more than $50tn worldwide, our campaign believes pensions to be citizens’ hidden superpower in fighting against catastrophic climate change.

Until recently, people like me never thought about where our pension money went and the impact it had. Our pensions have often left us accidental investors in many of the practices we condemn, and the causes we fight against. Since we launched, I’ve heard from peace campaigners unwittingly invested in weapons, doctors invested in tobacco, and environmentalists invested in coal, oil and deforestation. There’s a brilliant Ted talk by a cancer doctor called Bronwyn King who discovered that a lot of her money was invested in tobacco companies – she’d actually been killing more people with her investments than she’d been saving with her life’s work.

The good news is that where pensions were once poorly understood and easily ignored, they’re increasingly seen as a critical part of businesses’ sustainability plans, governments’ net-zero strategies, and individuals’ drive to reduce their carbon footprint. Research we’ve done shows that more than 20 million people are now aware that their pension may be contributing to the climate crisis. We’ve had huge numbers of people change their pensions, and seen more than GBP600bn committed to robust net-zero targets.

So ahead of Cop26, we’re asking for two things. First, we’ve spoken to the 100 biggest UK pension providers, calling on them to halve their emissions this decade and commit to net zero before 2050. Second, we’re joining forces with partners from across the country calling on the UK government to lead the world on green pensions by mandating that all providers commit to robust net zero.

In taking these critical steps, we can make sure our pensions take advantage of the enormous opportunities of the green industrial revolution, while protecting our savings against the ravages of climate change. And meanwhile – anyone reading this – do check if your own pension is cheating on you and ask if you can have a sustainable pension. This is a people’s movement – and the more pressure from below the better. And, be assured, it’s not a money v morals thing – the returns from sustainable pensions are almost always equal and increasingly often better than old-style ones.

With people across the world determined to make their money matter, and the demand for cleaner, greener pensions growing across society, now is the time for individuals, the financial industry and the government to put pensions at the heart of the climate agenda. And it makes such logical sense – what’s the point in collecting a pension in a world on fire?

• Richard Curtis is a filmmaker and activist