In 1492 Christopher Columbus landed on what he thought were the shores of India – except he had discovered a new continent. The ‘business case’ he presented to lure his funders was based on a gross miscalculation of the diameter of the Earth, but this mistake led him and his reluctant investors – among them the court of Isabella I of Castile – to a serendipitous success.

In 2010, the planet has shrunk dramatically. In just 500 years, we have moved from a world of few people, uncertainty about the proportions of the planet and virtually unlimited resources to a world of strained ecological limits, population pressures and climate change induced by growth models that date back to the Industrial Revolution.

But astonishing new insights are emerging from cutting-edge science. In 2009, the Stockholm Resilience Centre identified ten ‘planetary boundaries’ that make up the safe operating space for humanity (with climate change being just one), showing that we have already crossed the stability threshold for two of them – the loss of biodiversity and the concentration of nitrogen and phosphorous in the Earth’s cycles.[1] The poor will be hit first and hardest, as the tipping points in ecological stability affect the production of food and energy and the availability of water and land, and reinforce extreme temperatures and weather events.

We are only beginning to understand the critical interdependence between the economy, the biosphere and human security. Take the Amazon rainforest, which pumps 8 trillion tonnes of water a year into the atmosphere, regulating rainfall from South America to Tibet. Deforestation in the Amazon will generate acute water shortages in Brazil (to take one example), whose energy supply is 70 per cent dependent on hydropower. But little of this has made it to the central debate on deforestation and sustainability in the Amazon. Why not?