What's the world worth? Pavan Sukhdev, Centre for Policy Development, Sydney

Environmental damage is already costing us trillions a year, according to Pavan Sukhdev, head of the UN Green Economy Initiative. Sukhdev applies numbers to things that nature does for free - like purifying drinking water, supplying food and fuel, protecting coasts from storms, and generally keeping humans alive and healthy. The cost of the global financial crisis stunned the world, with an estimated $862 billion in direct government bailouts alone. After years of running down our natural capital, are we getting close to an environmental version of the credit crunch? Climate change has been grabbing most of the headlines in recent years, but we are now up against many environmental limits at once. Sukhdev looks at what this tells us about the limitations of our economic system and how it needs to change. The pioneering economist (who also works for Deutsche Bank) describes what the global economy would look like with nature on the balance sheet - and what that means for Australia. His talk was presented by the Centre for Policy Development at the Sydney Opera House. Afterwards, Pavan Sukhdev joined a panel consisting of leading business people, climate change advocates and scientists.