Twenty years ago the world's leaders did something tremendous. Meeting at the historic Earth summit in Rio, governments agreed that we must start living within our means. They saw that hoovering up or wrecking precious natural resources to get rich quick today would only leave us poorer tomorrow. Development would have to become more sustainable. Everybody would have to play their part.
Tomorrow morning I arrive in Brazil for Rio's 20-year reprise. I don't expect this week's meeting will be as show-stopping as that in 1992, but it matters just as much.
The legacy of the original Earth summit is under serious threat. There has been important progress, but actions have not met ambitions. Too many people still lack food: tonight, one billion will go hungry. There isn't enough clean energy: right now women in some of the poorest communities are fuelling their homes with tyres and plastics. Despite the noxious fumes produced, they rely on anything that will burn. Dirty water and poor sanitation kill a child every 30 seconds.
These aren't someone else's problems. We have a moral duty to help prevent this suffering, and we all share responsibility for the planet we leave behind. And in a global economy, resource scarcity affects everyone: food costs more; heating bills rise; far-flung conflicts drive extremism on our streets. In just 40 years the earth's population could increase by a staggering two billion. What will happen if there isn't enough food, water or energy for all those people? There'll be greater poverty, worse disease, more war – and we will all bear the cost.
So if 1992 was a breakthrough, 2012 must be about follow-through. Despite our continuing difficulties, developed economies must not sacrifice long-term sustainability in the name of short-term growth. It's a false choice: we need to strive for both. And the opportunities in the green economy are enormous. Last year the UK's low carbon sector grew by almost 5%.
In these uncertain times nations must also resist the temptation to turn inwards. Of course, individually, we must each do our bit. I'm proud that the UK is sticking to our commitment to spend 0.7% of gross national income on development by 2013. But it's a fact of modern politics that governments can only foster prosperity by working together. And in Rio we need a show of solidarity to drive three big shifts.
First, we want more national governments to broaden their understanding of wealth. Gross domestic product is vital in measuring economic performance, but it doesn't capture the full picture. It says nothing about natural capital – the forests, farmland, rivers, and coastline on which future prosperity depends. The UK is working on a kind of "GDP+" so that, by 2020, our national accounts reflect these assets. Botswana has pioneered this kind of thinking since the 1980s. The government calculates the cost to the environment from mining and then invests in other parts of the economy, like education, to offset the damage. We want to see others follow suit.
Second, Rio must set out a plan for the future. The best way to drive progress is through clear ambitions with hard deadlines. The millennium development goals were designed to alleviate poverty throughout the world, and have galvanised dozens of states and international organisations around that task. The UN's High Level Panel – co-chaired by the prime minister and the presidents of Liberia and Indonesia – will lead an inclusive, transparent process to help shape a new generation of development goals when the millennium development goals expire in 2015. Rio will be a critical step along the way. We're proposing a package of sustainable development goals to rally the international community around ensuring that all people, everywhere, have access to food, clean water and green energy. Agreeing these will be a huge undertaking – but this week we need to get them off the ground.
And finally, we need to bring business in. Using resources responsibly is in business's own interests too. Pepsi depends on water, Unilever depends on fish stocks and agricultural land, and every firm relies on a stable fuel supply. But while nine out of 10 chief executives say sustainability is fundamental to their success, only two out of 10 record the resources they consume. So the UK will press for governments to come together, working with those companies already blazing a trail, to give "sustainability reporting" a global push. By agreeing common standards and practices we can get many more firms on board. And in the UK, from the start of next financial year, all firms listed on the London Stock Exchange will have to report the levels of greenhouse gases they emit.
On each of these fronts, ambition will be key. We must revive the spirit of our predecessors to get the world on to a more sustainable path. Twenty years on from the Earth summit, we need to get back on track.
Article originally appeared in The Guardian.