Why read popular science? The best books manage to entertain, educate, astonish and even galvanise the reader, bringing an appreciation of new realms of knowledge. They expand awareness, not just of the beauty and complexity of the universe, but our place in it as human beings. They serve as celebrations and warnings, challenges and pleas. Traditionally, the genre tends to garland hard data with lashings of anecdote and well-turned, elegant metaphor. With Becoming Earth, Oregon-based journalist Ferris Jabr achieves all of these aims and more. He takes James Lovelock’s Gaia hypothesis, which proposed a reframing of Earth as a living being, and shows how “the history of life on Earth is the history of life remaking Earth” in perpetual feedback spirals. “Becoming Earth is an exploration of how life has transformed the planet, a meditation on what it means to say that Earth itself is alive, and a celebration of the wondrous ecology that sustains our world.”
It’s a vision thick with baroque possibilities, potentially endless, and Jabr simplifies his mission by dividing his book into three sections: rock, water and air. In Rock, he journeys a mile underground and learns that as much as 20% of the Earth’s biomass – the collective weight of all living things – may be simple organisms that live deep within the earth. There are some microbes that flourish in the cracks between rocks, magma-heated to 60C, and which get their energy from radioactive uranium; he describes others that live for millions of years. The weathering effect of bacteria, fungi and lichens has, over eons, created the silts that have lubricated plate tectonics, creating our continents. “Computer models suggest that on a barren planet, the expansion of the continents would have been severely stunted and Earth would have remained a water world flecked with islands.”
For much of the past 100,000 years, up to 40% of the world’s landmass was covered in prairies now known as “mammoth steppe”. These dominated the northern hemisphere and were among the richest ecosystems the world has ever seen – populated not only with mammoths, but also mastodons, rhinos, bison, bears, lions, dire wolves and muskoxen. We’re accustomed now to thinking of modern humans as the wreckers of ecosystems, but our prehistoric ancestors were no better – they killed this habitat off. Between 50,000 and 10,000 years ago, humans steadily destroyed large steppe animals; as a consequence, mammoth steppe gradually ceded to the kind of species-poor coniferous forest that now covers much of Russia. Jabr’s Russian guide Sergey Zimov (who has been instrumental in showing how rewilding that steppe mitigates the climate crisis, promotes biodiversity and pulls carbon back into the soil) calls the great forest of Siberia “weeds covering the cemetery of mammoth steppe”. Jabr goes to see for himself the large herbivores that are transforming Zimov’s nature reserve of Pleistocene Park. “They had become the stewards of their realm,” he says of them, “the architects of their own Eden.” Architects of Eden could easily have been an alternative title for this book.
The sea’s plankton is the engine of all life on Earth; without the cyanobacteria that generated atmospheric oxygen, life wouldn’t have got much further than single-celled microbes. The diving and surfacing of large sea creatures churn the oceans more even than winds and tides, helping to spread nutrients and nourish sea life. The seesaw interplay of atmospheric oxygen and carbon dioxide over millions of years has repeatedly cycled our planet through phases Jabr calls “snowball earth” and “swampland”, but he explores how microorganisms blown up into the sky too have been pivotal in engineering our climate – some have evolved proteins that raise the freezing temperature of water, giving themselves “a return ticket to the surface” when they seed clouds of snow. These organisms have profoundly altered our planet’s climate (they’re of commercial use too: ski resorts can use their proteins to generate snow more easily from water).
It’s long been known that trees make clouds and it’s now appreciated that the Amazon forest generates half of the rain that falls on it. More water is drawn every day from the Amazon basin into the sky than pours out into the ocean. The forests of South America offer Jabr some of his most resonant metaphors: “A cloud is Earth seeing its own breath,” he writes “… a levitating lake, typically weighing more than several blue whales. A cloud is aerial alchemy, at once liquid, vapour, and crystal.” But his observations regarding fossil fuels are no less striking: the US has emitted one-quarter of the excess CO2 in our skies, he observes, while China, with more than triple the population, has emitted just an eighth of it. The 19th-century technology of burning fossil fuels still generates 80% of the energy humanity uses. And all that carbon we’re burning took millions of years to accumulate. I hadn’t realised that there’s 100 tonnes of ancient life in a single gallon of petrol.
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The final sections of Becoming Earth focus on wildfires in North America and how they can be prevented by adopting traditional Native American techniques of fire suppression, which were themselves suppressed by European colonisers. He closes with a litany of terrifying statistics on the climate calamities of the last few years, but ends on a note of hope; as part of life, we are both problem and resolution. Even just to reform our stewardship of the soil could, by 2100, return CO2 to preindustrial levels. Scientists have created enzymes that can break down plastic pollution. Jabr quotes Jonathan Foley, environmental scientist and campaigner: “I am more optimistic now than I have ever been about climate,” Foley said. “We’re only doomed if we choose to be … So what are we going to choose to do?”
Solutions are not only available, they are achievable. For too long we have considered life as something that happened on Earth, “the manger that housed a miracle”. But “Life is Earth,” Jabr concludes – “our living Earth is the miracle”.
Gavin Francis’s latest book, The Bridge Between Worlds: A Brief History of Connection, is published on 12 September by Canongate (£20). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply