Earth is home to millions of species. Just one dominates it. Us. As we continue to grow towards a global population of 10 billion, we are facing an unprecedented planetary emergency, writes Stephen Emmott in an edited extract from his new book.

There are now more than 7 billion of us on Earth. As our numbers carry on growing, we continue to increase our need for far more water, far more food, far more land, far more transport and far more energy. As a result, we are accelerating the rate at which we’re changing our climate.

There is a politically agreed global target – driven by the Intergovernmental Panel on Climate Change (IPCC) – to limit the global average temperature rise to 2°C. The rationale for this target is that a rise above 2°C carries a significant risk of catastrophic climate change that would almost certainly lead to irreversible planetary “tipping points”, caused by events such as the melting of the Greenland Ice Shelf, the release of frozen methane deposits from Arctic tundra, or dieback of the Amazon. In fact the first two are happening now – at below the 2°C threshold. As for the third, we’re not waiting for climate change to do this: we’re doing it right now through deforestation. And unfortunately, recent research shows that we look certain to be heading for a larger rise in global average temperatures than 2°C – a far larger rise.

What about political action to address these problems? Here, politicians are currently part of the problem, not the solution.  What politicians have opted for is failed diplomacy. For example, the UN Framework Convention on Climate Change, whose job for 20 years has been to ensure the stabilization of greenhouse gases in the Earth’s atmosphere: Failed.

The UN Convention to Combat Desertification, whose job for 20 years has been to stop land degrading and becoming desert: Failed.

The Convention on Biological Diversity, whose job for 20 years has been to reduce the rate of biodiversity loss: Failed.

It looks like 20 years of words and inaction is set to continue with another 20 years of words and inaction. All the while, we are heading into deeper and deeper trouble.

If we discovered tomorrow that there was an asteroid on a collision course with Earth, and we were able to calculate that it was going to hit Earth on 3 June 2072, and we knew that its impact was going to wipe out 70% of all life on Earth, governments worldwide would marshal the entire planet into unprecedented action. Every scientist, engineer, university and business would be enlisted: half to find a way of stopping it, the other half to find a way for our species to survive and rebuild if the first option proved unsuccessful. We are in almost precisely that situation now, except that there isn’t a specific date and there isn’t an asteroid.

The problem is us.

This is an edited extract from 10 Billion, by Stephen Emmott (Penguin)

Author: Stephen Emmott is Head of Microsoft’s Computational Science Laboratory in Cambridge.

Image: Commuters are seen in a subway station in Sao Paulo REUTERS/Nacho Doce