implications of meeting the boundaries. There are substantial caveats and uncertainties, as always, and disagreement can be expected between other experts about whether a ‘planetary boundary’ is truly relevant, and if so, what its limit should be – not to mention how we should meet it. This is first-draft work, Planetary Boundaries 1.0 if you will; there cannot fail to be teething problems. Even so, factual statements in this book are based wherever possible on the peer-reviewed scientific literature – the gold standard for current knowledge. References are at the back, and I urge all readers to make good use of them.
Many will find my analysis and conclusions rather unsettling – not least my colleagues in the Green movement, many of whose current preoccupations are shown to be ecologically wrong. Until now, environmentalism has been mostly about reducing our interference with nature. Central to the standard Green creed is the idea that playing God is dangerous. Hence the reflexive opposition to new technologies from splitting the atom to cloning cattle. My thesis is the reverse: playing God (in the sense of being intelligent designers) at a planetary level is essential if creation is not to be irreparably damaged or even destroyed by humans unwittingly deploying our new-found powers in disastrous ways. At this late stage, false humility is a more urgent danger than hubris. The truth of the Anthropocene is that the Earth is far out of balance, and we must help it regain the stability it needs to function as a self-regulating, highly dynamic and complex system. It cannot do so alone.
This means jettisoning some fairly sacred cows. Nuclear power is, as many Greens are belatedly realising, environmentally almost completely benign. (The Fukushima disaster in Japan did nothing to change this sanguine assessment, and perhaps more than anything reconfirmed it: more on that later.) Properly deployed, nuclear fission is one of the strongest weapons in our armoury against global warming, and by rejecting it in the past campaigners have unwittingly helped release tens of billions of tonnes of carbon dioxide into the atmosphere as planned nuclear plants were replaced by coal from the mid-1970s onwards. Anyone who still marches against nuclear today, as many thousands of people did in Germany following the Fukushima accident, is in my view just as bad for the climate as textbook eco-villains like the big oil companies. (Germany’s over-hasty switch-off of seven of its nuclear power plants after the Japanese tsunami will have led to an additional 8 million tonnes of carbon dioxide in just three months.3) The same goes for genetic engineering. The genetic manipulation of plants is a powerful technology that can help humanity limit its environmental impact and feed itself better in the process. I personally campaigned against it in the past, and now realise that this was a well-intentioned but ignorant mistake. The potential of synthetic biology I can only begin to guess at today in early 2011. But the lesson is clear: we cannot afford to foreclose powerful technological options like nuclear, synthetic biology and GE because of Luddite prejudice and ideological inertia.
Indeed, if we apply the metric of the planetary boundaries to the campaigns being run by the big environmental groups, we find that many of them are irrelevant or even counterproductive. Carbon offsetting is a useful short-term palliative that the Green movement has discredited without good reason, harming both the climate and the interests of poor people in the process. Some Green groups have also made it very difficult to use the climate-change negotiations as a way to save the world’s forests by insisting that rainforest protection should not be eligible for carbon credits. In addition, environmental and development NGOs in general have been much too easy on rapidly emerging big carbon emitters like China and India, whose governments need to be pressed or assisted to eschew coal in favour of cleaner alternatives. Blaming the rich countries alone for climate change may tick all the right ideological boxes, but it is far from being the full story.
Most Greens also emphatically object to geoengineering – the idea that we could consciously alter the atmosphere to counteract climate change, for example by spraying sulphates high in the stratosphere to act as a sunscreen. But the objectors seem to forget that we are already carrying out massive geoengineering every day, as a hundred million people step into their cars, a billion farmers dig their ploughs into the soil, and 10 million fishermen cast their nets. The difference seems to come down to one of intent: is unwitting and bad planetary geoengineering really better than witting and good planetary geoengineering? I am not so sure. At the very least a reflexive rejectionist position risks repeating the mistakes of the anti-genetic engineering campaign, where opposing a technology a priori meant that lots of potential benefits were stopped or delayed for no good cause. Being against something can have just as big an opportunity cost as being for it.
Certainly deciding on something as epochal as intentional climatic geoengineering would involve us in some truly awesome collective decisions, which we have only just begun to evolve the international governance structures to manage. But if we want the Anthropocene to resemble the Holocene rather than the Eocene (roughly 55–35 million years ago, which was several degrees hotter and had neither ice caps nor humans) we will need to act fast. On climate change, meeting the proposed planetary boundary means being carbon-neutral worldwide by mid-century, and carbon-negative thereafter. The former will not be possible in my view without nuclear new-build on a large scale, and the latter will need the deployment of air-capture technologies to reduce the concentration of ambient CO2. On biodiversity loss, we need to rapidly scale up ‘payments for ecosystem services’, schemes that use private and public-sector approaches to make planetary ecological capital assets like rainforests and coral reefs worth more alive than dead. To meet the other boundaries we will need to deploy genetically engineered nitrogen- and water-efficient plants, remove unnecessary dams from rivers, eliminate the spread of environmental toxins like dioxins and PCBs, and get much better at making and respecting international treaties. We can learn a great deal from the success of ozone-layer protection, which remains a shining example of how to do it right.
Most importantly, environmentalists need to remind themselves that humans are not all bad. We evolved within this living biosphere, and we have as much right to be here as any other species. Through our intelligence, Mother Earth has seen herself whole and entire for the first time from space4. Thanks to us she can even hope to protect herself from extraterrestrial damage: we now operate a programme to track large meteorites like the one that destroyed a significant portion of the biosphere at the end of the Age of Dinosaurs. The Age of Humans does not have to be an era of hardship and misery for other species; we can nurture and protect as well as dominate and conquer. But in any case, the first responsibility of a conquering army is always to govern.
Chapter One
The Ascent of Man
Three large rocky planets orbit the star at the centre of our solar system: Venus, Earth and Mars. Two of them are dead: the former too hot, the latter too cold. The other is just right, and as a result has evolved into something unique within the known universe: it has come alive. As Craig Venter and his team of synthetic biologists have shown, there is nothing chemically special about life: the same elements that make up our living biosphere exist in abundance on countless other planets, our nearest neighbours included. But on Earth, these common elements – carbon, hydrogen, nitrogen, oxygen and many more – have arranged themselves into uncommon patterns. In the right conditions they can move, grow, eat and reproduce. Through natural selection, they are constantly changing, and all are involved in a delicate dance of physics, chemistry and biology that somehow keeps Earth in its Goldilocks state, allowing life in general to survive and flourish, just as it has done for billions of years.
Why the Earth has become – and has remained – a habitable planet is one of the most extraordinary stories in science. Whilst Venus fried and Mars froze, Earth somehow survived enormous swings in temperature, rebounding back into balance whatever the initial cause of the perturbation. Venus suffered a runaway greenhouse effect: its oceans boiled away and most of its carbon ended up in the planet’s atmosphere as a suffocatingly heavy blanket of carbon dioxide. Mars, on the other hand, took a different trajectory. It began life warm and wet, with abundant liquid water. Yet something went wrong: its carbon dioxide ended up trapped for ever in carbonate rocks, condemning the planet to an icy future from which there could be no return.1 The water channels and alluvial fans that cover the planet’s surface are now freeze-dried