trawled round the clock for the fishy fats and proteins our brains and bodies demand. In sum, somewhere between a quarter and a third of the entire planetary ‘net primary productivity’ (everything produced by plants using the power of the sun) is today devoted to sustaining this one species – us.
With close to 7 billion specimens of Homo sapiens currently in existence, mostly enjoying rising (though highly variable) levels of wealth and material consumption, human beings have so far been an evolutionary success story unprecedented in the entire history of planet Earth. But there is a dark side to this momentous achievement. For the biosphere as a whole the Age of Humans has been a catastrophe. Our domestication of the planet’s surface to provide crops and animals for ourselves has displaced all competing species to the margins. The Earth is now in the throes of its sixth mass extinction, the worst since the ecological calamity that wiped out the dinosaurs 65 million years ago. Evolution is about competition – and we have outcompeted them all. No other species can control our numbers and return balance to the system (though extremely virulent microbes are likely to come closest). Whenever we have appeared on the verge of shortages, either in food production or fuel for our ever-rising energy demands, we have saved ourselves through brainpower and the judicious application of technology. The worst plague, flood or world war – which may singly or combined cause horrifying loss of life – is just a blip in this relentless upward trend.
But most amazing of all perhaps is how blissfully unaware of this colossal transformation we remain. We are phenomenally, stupendously, ignorant. As if God were blind, deaf and dumb, we blunder on without any apparent understanding of either our power or our potential. Even most Greens – ever hopeful that vanished wild nature can one day be restored – still recoil from the real truth about our role. Climate-change deniers are successful not just because of the moneyed vested interests they serve, but because they tap into a powerful cultural undercurrent that insists we are small and the planet is big, ergo nothing we do – not even in our collective billions – can have a planet-scale impact. The world’s major religions, founded as they were in an earlier, more innocent age, share this insistence, as if the Book of Genesis could still be anything more than a historical metaphor in an era of Earth science and biochemistry. Our culture and politics languishes decades behind our science.
To most people my contention that humans are now running the show smacks of hubris. Consequently everyone loves a good disaster, because it makes us feel small. After the 2004 Asian tsunami there were honest discussions over the benevolence or otherwise of God. Those in the path of hurricanes often speak about the anger of Mother Nature. When the Icelandic volcano Eyjafjallajokull erupted in April 2010, news reports reminded us of ‘nature’s awesome power over humans’, as if a few grounded aircraft in Europe had humbled us helpless clumsy apes. The Japanese earthquake and resulting tsunami disaster in March 2011 showed nature’s force at its most powerful and destructive, but many lives were saved because of warning systems and strict building codes. We may not be able to stop earthquakes, but the idea of perennial human victimhood is now somewhat out of date. I suspect there is a reason why most of us cannot bear to let go of it, however, for admitting that we hold the levers of power over the Earth’s major cycles would mean having to take conscious decisions about how the planet should be managed. This is an idea so difficult to contemplate that most people simply prefer denial, relieving themselves of any inconvenient burden of responsibility. What you don’t know can’t hurt you, right?
This see-no-evil approach is particularly convenient for politically motivated climate-change deniers. Take Newt Gingrich, the US Republican firebrand who almost single-handedly destroyed the Clinton presidency and is now taking aim at Obama too. He told the American environment website Grist.org in June 2010: ‘It’s an act of egotism for humans to think we’re a primary source of climate change. Look at what happened recently with the Icelandic volcano. The natural systems are so much bigger than manmade systems.’1 QED, as I think they say.2
Gingrich and his ilk may be an extreme case, but this degree of ignorance and denial cannot go on for much longer. Instead, I suggest that since nature can no longer tame us, then we must tame ourselves. Recognising that we are now in charge – whether for good or ill – we need to take conscious and collective decisions about how far we interfere with the planet’s natural cycles and how we manage our global-scale impacts. This is not for aesthetic reasons, or because I mourn the loss of the natural age. It is too late for that now, and – as my uncle always says – one must move with the times. Instead, the overwhelming weight of scientific evidence suggests that we are fast approaching the point where our interference in the planet’s great bio-geochemical cycles is threatening to endanger the Earth system itself, and hence our own survival as a species. To avert this increasing danger, we must begin to take responsibility for our actions at a planetary scale. Nature no longer runs the Earth. We do. It is our choice what happens from here.
This book aims to demonstrate how our new task of consciously managing the planet, by far the most important effort ever undertaken by humankind, can be tackled. The idea for it came to me in a moment of revelation two years ago in Sweden, during a conference in the pretty lakeside village of Tällberg. I was invited to join a group of scientists meeting in closed session to discuss the concept of ‘planetary boundaries’, a term coined by the Swedish director of the Stockholm Resilience Centre, Professor Johan Rockström. The scientists – all world experts in their fields – were trying to nail down which parts of the Earth system were being most affected by humans, and what the implied limits might be to human activities in these areas. Some, like climate change and biodiversity loss, were familiar and obvious contenders for top-level concern. Others, like ocean acidification and the accumulation of environmental toxins, were newer and less well-understood additions to the stable.
During hours of debate, and with much scribbling of numbers and spider diagrams on flip-chart paper, humanity’s innumerable list of ecological challenges was reduced to just nine. I left the room late that afternoon certain that something radical had just happened, but not quite sure what it was. It wasn’t until later in the evening – in the shower of all places – that I understood in a flash just how important the planetary boundaries concept could be. I realised that scientists studying the Earth system were now in a position to define what mattered at a planetary level, and that this knowledge could and should be the organising basis for a new kind of environmental movement – one that left behind some of the outdated concerns of the past to focus instead on protecting the planet in the ways that really counted. Of course all knowledge is tentative, but here was something very tangible: for the first time, world experts were not just listing our problems, but putting numbers on how we should approach and solve them. I tracked down Johan Rockström and we shared a beer in the hotel lobby. He was encouraging, and we agreed that my job as a writer and as an environmentalist should be to do what the scientists could not: get this scientific knowledge out into the mainstream and demand that people – campaigners, governments, everyone – act on it. Hence this book.
The planetary boundaries concept of course builds on past work conducted by experts in many different fields, from geochemistry to marine biology. But its global approach is actually very new and potentially quite revolutionary. Unlike, say, the 1972 Limits to Growth report produced by the Club of Rome, the planetary boundaries concept does not necessarily imply any limit to human economic growth or productivity. Instead, it seeks to identify a safe space in the planetary system within which humans can operate and flourish indefinitely in whatever way they choose. Certainly this will require limiting our disturbance to key Earth-system processes – from the carbon cycle to the circulation of fresh water – but in my view this need constrain neither humanity’s potential nor its ambition. Nor does it necessarily mean ditching capitalism, the profit principle, or the market, as many of today’s campaigners demand. Above all, this is no time for pessimism: we have some very powerful tools available to allow us to live more gently on this planet, if only we choose to use them.
In this book I take the planetary boundaries concept further into the social, economic and political realms than the original experts were able to. Although some of the planetary boundaries expert group have generously helped to check my facts and figures, I do not expect them to agree with all my suggestions