Wdo you read popular science? The best books manage to entertain, educate, amaze and even excite the reader, bringing an appreciation for new areas of knowledge. They increase awareness, not only of the beauty and complexity of the universe, but our place in it as humans. They serve as celebrations and warnings, challenges and pleas. Traditionally, the genre tends to sling hard data with slings of anecdote and well-turned, elegant metaphor. With earth becomes Oregon-based journalist Ferris Jabr achieves all these goals and more. He takes James Lovelock’s Gaia Hypothesiswhich suggested a reformulation of the earth as a living being, showing how “the history of life on earth is the history of life recreating the earth” in perpetual feedback spirals. “Earth becomes is an exploration of how life has changed the planet, a meditation on what it means to say that the earth itself is alive, and a celebration of the amazing ecology that sustains our world.”
It is a vision full of baroque possibilities, potentially endless, and Jabr simplifies his mission by dividing his book into three sections: rock, water and sky. In Rock, he travels a mile underground and learns that as much as 20% of the Earth’s biomass – the combined weight of all living things – may be simple organisms that live deep within the earth. There are some microbes that thrive in the cracks between rocks, magma-heated to 60C, and that get their energy from radioactive uranium; he describes others living for millions of years. The weathering effect of bacteria, fungi and lichens over centuries created the silt that lubricated plate tectonics, creating our continents. “Computer models suggest that on a barren planet, the expansion of the continents would have been severely hampered and Earth would have remained a water world with islands.”
For much of the past 100,000 years, up to 40% of the world’s land mass was covered in prairies now known as “mammoth steppes”. These dominated the northern hemisphere and were some of the richest ecosystems the world has ever seen – populated not only with mammoths, but also mastodons, rhinos, bison, bears, lions, terrifying wolves and mouse dogs. We are now used to thinking of modern humans as the destroyers of ecosystems, but our prehistoric ancestors were no better – they killed this habitat. Between 50,000 and 10,000 years ago, humans gradually destroyed large steppe animals; as a result, mammoth steppes gradually gave way to the kind of species-poor coniferous forest that now covers much of Russia. Jabr’s Russian guide Sergey Zimov (who was instrumental in showing how those steppes are once again mitigating the climate crisis, promoting biodiversity and sequestering carbon back into the soil) calls the great forest of Siberia “weeds covering the graveyard of mammoth steppes”. Jabr goes to see for himself the large herbivores that are transforming Zimov’s nature reserve Pleistocene Park. “They became the stewards of their riches,” he says of them, “the builders of their own Eden.” Architects of Eden could easily have been an alternative title for this book.
The ocean’s plankton is the engine of all life on Earth; without the cyanobacteria that generated atmospheric oxygen, life would not have progressed much beyond single-celled microbes. The diving and surfacing of large sea creatures leave the oceans more level than winds and tides, which helps distribute nutrients and feed marine life. The see-saw interaction of atmospheric oxygen and carbon dioxide over millions of years has cycled our planet repeatedly through phases that Jabr calls “snowball earth” and “swampland,” but he explores how airborne microorganisms have also been crucial in engineering our climate. – some have developed proteins that raise the freezing point of water, giving themselves “a return ticket to the surface” when they seed snow clouds. These organisms have profoundly changed our planet’s climate (they are also of commercial use: ski resorts can use their proteins to more easily generate snow from water).
It has long been known that trees make clouds and it is now appreciated that the Amazon forest generates half of the rain that falls on it. More water is pumped into the air from the Amazon basin every day than flows into the ocean. The forests of South America provide Jabr with some of his most resonant metaphors: “A cloud is the earth seeing its own breath,” he writes “… a floating lake, typically weighing more than several blue whales. A Cloud is aerial alchemy, simultaneously liquid, vapor and crystal.” But his observations about fossil fuels are no less striking: the US emitted a quarter of the excess CO2 in our air, he notes, while China, with more than triple the population, emitted only an eighth of that. The 19th century technology of burning fossil fuels still generates 80% of the energy used by humanity. And all that carbon we burn took millions of years to accumulate. I didn’t realize that there is 100 tons of ancient life in a single gallon of gasoline.
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The last sections of Earth becomes focuses 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 colonizers. He concludes with a litany of frightening statistics about the climate disasters of the last few years, but ends on a note of hope; as part of life we are both problem and solution. Even just reforming our stewardship of the land could return CO by 21002 to pre-industrial levels. Scientists have created enzymes that can break down plastic pollution. Jabr quotes environmental scientist and campaigner Jonathan Foley: “I’m more optimistic now than I’ve ever been about climate,” Foley said. “We are 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 viewed life as something that happened Earth, “the crypt that housed a miracle”. But “Life is Earth,” concludes Jabr – “our living Earth is the miracle”.
Gavin Francis’ latest book, The Bridge Between Worlds: A Brief History of Connectionis published by Canongate (£20) on 12 September. To the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply
