It is often said that it takes great ideas in science some forty years to gain widespread acceptance. Sadly for us all, James Lovelock’s concept of a self-regulating Earth has fitted this mould with a frustrating and yet thoroughly predictable punctuality: had acceptance come sooner we would by now have been much further advanced in our understanding of the dangers of climate change.

It was in 1965, whilst thinking of a workable life-detection experiment for a NASA mission to Mars, that Lovelock received a “flash of enlightenment” which would lead him to overturn a notion widely held by scientists at the time: that living beings are merely passive passengers on an Earth governed mostly by geological, chemical and physical processes. Not so, said Lovelock – life’s tightly coupled feedbacks with the abiotic domains of atmosphere, rocks and water configure the Earth into a dynamic, evolving planet that has actively maintained its surface in a state suitable for life over thousands of millions of years despite the vagaries of plate tectonics and an ever-brightening sun.

Thinking of the Earth as a system with life at centre stage was a challenging and controversial proposal that met with severe disapproval from the scientific community, more so because Lovelock had dared to name his theory of a self-regulating planet after Gaia, the ancient Greek divinity of the Earth. But in responding to his critics, Lovelock was forced, over many years, to produce convincing models, to gather evidence and to hone his arguments in ways that developed in him a unique and resilient understanding of our Earth as a living planet and of the impact of humans upon its tangled web of relationships.

Lovelock’s long devotion to establishing the science of Gaia has at last come to fruition – many scientists no longer deny that life plays important roles in configuring the Earth’s climate, or that the Earth is a complex dynamic system with oftentimes surprising emergent behaviours, including sudden shifts from one semi-stable state to another.

In this, his latest book, published in the year of his ninetieth birthday, Lovelock uses his matchless transdisciplinary Gaian viewpoint to eloquently warn us, once again, about the severe dangers that our destruction of wild ecosystems and our burning of fossil fuels are likely to bring us in the very near future. He cautions us that most mathematical models run on supercomputers to predict climate change over the next century, including the many models collated by the Intergovernmental Panel on Climate Change (IPCC), vastly underestimate the likely severity of the problem because they “do not yet include the physiological response of the ecosystems of the land or ocean”.

In other words, most of these models deal only with the physics and chemistry of the air and oceans, and leave out life’s impacts on climate altogether, not because scientists deny their importance, but because our technical and mental capacities are not advanced enough to include them. This shortcoming of conventional climate models is increasingly recognised and yet politicians glibly use the IPCC predictions of smooth and therefore potentially manageable change to create strategies for a supposedly liveable future. Instead, says Lovelock, policymakers should compare the IPCC projections with what is happening in the real world.

Pay close attention to sea-level rise, he says, for this is “a thermometer which indicates true global warming” because it only comes about in two main ways: through the melting of land-based ice and through the thermal expansion of the oceans, both of which only take place on a warming planet. He shows us sea- level data, which is decidedly worrying: in 2007 observed sea level had risen 1.6 times faster than predicted by the IPCC.

We also discover other observations of the real Earth that are equally alarming. By 2007 the area of the Arctic Ocean covered by summertime floating ice had fallen to 4 million square kilometres, a condition that the IPCC models predicted was unlikely before 2050. If this trend continues, within fifteen years all the Arctic sea ice will have melted in summer and the extra heating caused by the sun’s warming of the dark ocean will be equivalent to that caused by all the anthropogenic carbon dioxide now present in the atmosphere.

Lovelock also points to a third process of immense significance for the Earth’s climate that the IPCC models seem to have ignored altogether: the shockingly rapid loss of planet-cooling marine algae caused by our warming of the oceans.

Lovelock explores what sort of climate we can expect to experience over the next decade or so due to these changes, using one of his simple but powerful Gaian models that includes feedbacks between oceanic algae, land plants and global mean temperature. To begin with, not much happens when the model is forced with increasing emissions of carbon dioxide, but when the atmospheric concentration of the gas reaches between 400 and 500ppm, global average temperature suddenly increases by 5 °C, after which the model stabilises in this new, hot state. In contrast to the non-Gaian models of the IPCC, which predict smooth linear changes, Lovelock’s model captures the dynamics of the real Earth, where similarly rapid changes have not been uncommon.

His prognosis, now shared by increasing numbers of eminent climate scientists, is that with around 380ppm carbon dioxide currently in the atmosphere, a sudden catastrophic warming is either currently in process or is extremely likely. In the hot state much of the Earth will become uninhabitable due to desertification in the low latitudes and severe weather elsewhere. As a result, within decades billions of people will lose their lives. The survivors will be forced to seek refuge in the high latitudes, particularly in the northern hemisphere. Things will also go badly for the biosphere, which will experience an extinction event of gargantuan proportions that will make the warming more severe as forests burn and marine algae disappear.

SO, WHAT CAN be done to avert this dreadful prognosis? Lovelock urges us to make adaptation “at least equal in importance to policy-driven attempts to reduce emissions”. What he means by adaptation beggars the imagination: for the UK and many countries in the north it means preparing for a huge influx of climate refugees. He suggests that we will need to create mega-cities to house the billions of people who will be displaced, we will need to grow food chemically to feed them and we will need to generate the electricity they will need, for the most part, using nuclear power.

Most forms of renewable energy, carbon trading, offset schemes and so on are dismissed by Lovelock as largely ineffectual, given the little time left to ameliorate the situation, if indeed this is possible at all. His one ray of hope for renewables is solar thermal energy deployed in the deserts of the world to generate electricity from steam-driven turbines.

Lovelock examines each of the major contenders for engineering our way out of trouble, including putting mirrors in space, introducing cooling aerosols of sulphuric acid droplets into the stratosphere and fertilising the oceans with iron to feed planet-cooling algae. He doubts that these measures will stop the warming: at best they can only reduce its early consequences. His favourite ‘geo-engineering’ option is biochar – in which carbon captured from the atmosphere by photosynthesis is fixed by making charcoal – but my own delving into this possibility has convinced me that it probably won’t work. There are serious doubts about whether the carbon in the biochar is stable for significantly long periods of time, and we simply don’t have time to find out.

One might think that Lovelock were both pessimistic and misanthropic, but nothing could be further from the truth. He hopes that the few survivors of the catastrophe will create a new civilisation that is truly in tune with Gaia. It took the Earth some 3½ thousand million years to produce human intelligence, so his hope is that one day we will become the “hearts and minds of Gaia”, wise enough to regulate our own numbers and skilled enough in science and technology to maintain her habitability and protect her from harm. Only then, he says, will Gaia have become a “truly sentient planet”. In the meantime, Lovelock’s well argued yet passionate “final warning” needs to be taken with utmost seriousness, for it is now blindingly obvious that business as usual is wreaking huge and unremitting havoc upon the Earth.

Stephan Harding is the Co-ordinator of the MSc in Holistic Science at Schumacher College, where he is also Ecologist in Residence. He is author of Animate Earth published by Green Books.