My brother asked me if I could remember seeing this, and before I had tracked it down, he emailed me back with a link to this very interesting video about the exponential speed of growth of humanity.
Which reminded me of this excellent article in Time about how we are killing our home planet. We may be getting smarter, but we’re also not getting any brighter about what we need to do to keep living on this rock.
On February 5, a team of Russian scientists in Antarctica made history. Working on and off for nearly a decade in the inhospitable climate, the researchers, who had been drilling through two miles (3.2 km) of solid ice, finally reached their goal: the subglacial Lake Vostok, whose liquid water had been sealed off from light and air for up to 34 million years. The lake could contain previously unknown forms of microbes, and because the water’s temperature and chemical makeup resemble the environment found on Europa, one of Jupiter’s icy moons, Lake Vostok may even help us understand how life could exist on other planets. But the Vostok expedition is also extraordinary because it enabled scientists to reach a part of the planet that had never before been touched by human beings. Lake Vostok was one of the very few truly pristine places on earth in 2012, and now we’re starting to tinker with it too.
For a species that has been around for less than 1% of 1% of the earth’s 4.5 billion-year history, Homo sapiens has certainly put its stamp on the place. Humans have had a direct impact on more than three-quarters of the ice-free land on earth. Almost 90% of the world’s plant activity now takes place in ecosystems where people play a significant role. We’ve stripped the original forests from much of North America and Europe and helped push tens of thousands of species into extinction. Even in the vast oceans, among the few areas of the planet uninhabited by humans, our presence has been felt thanks to overfishing and marine pollution. Through artificial fertilizers—which have dramatically increased food production and, with it, human population—we’ve transformed huge amounts of nitrogen from an inert gas in our atmosphere into an active ingredient in our soil, the runoff from which has created massive aquatic dead zones in coastal areas. And all the CO2 that the 7 billion-plus humans on earth emit is rapidly changing the climate—and altering the very nature of the planet.
Human activity now shapes the earth more than any other independent geologic or climatic factor. Our impact on the planet’s surface and atmosphere has become so powerful that scientists are considering changing the way we measure geologic time. Right now we’re officially living in the Holocene epoch, a particularly pleasant period that started when the last ice age ended 12,000 years ago. But some scientists argue that we’ve broken into a new epoch that they call the Anthropocene: the age of man. “Human dominance of biological, chemical and geological processes on Earth is already an undeniable reality,” writes Paul Crutzen, the Nobel Prize—winning atmospheric chemist who first popularized the term Anthropocene. “It’s no longer us against ‘Nature.’ Instead, it’s we who decide what nature is and what it will be.”
Humans have been changing the planet ever since the dawn of agriculture 10,000 years ago, when Homo sapiens began altering the land—and the plants and animals growing on it—rather than simply living as hunters and gatherers. Agriculture enabled humans to proliferate and literally changed the face of the planet; today 38% of the earth’s ice-free land has been cleared and cultivated for farming. But it wasn’t until the dawn of the Industrial Revolution around 1800 that human growth and its impact on the environment began to explode, and that’s the moment when many scientists believe the Anthropocene truly began.
Since then our ranks have ballooned from 1 billion to 7 billion, a rate of reproduction that biologist E.O. Wilson has characterized as “more bacterial than primate.” Today the total human biomass is a hundred times as great as that of any other large animal species that has ever walked the earth. That growth has been aided by the use of fossil fuels as humans have learned to tap coal, oil and natural gas, which has steadily warmed the atmosphere and further altered the planet.
After World War II we added nuclear power to the mix—making radioactive fallout one more physical mark of our presence—and global population and economic expansion went into overdrive. The change has been so rapid that scientists have dubbed the past half-century the Great Acceleration—and this period shows little sign of slowing as economic growth and improved health care extends the life spans and turbocharges the resource use of billions of people in the developing world.
That’s why the Anthropocene demands a dramatic change for environmentalism. Since the days of John Muir—the 19th century Scottish-American naturalist who founded the Sierra Club—the goal of environmentalism has been the preservation of wilderness. Muir fought to create some of the U.S.’s first national parks, in Yosemite and the sequoia forest, with the aim of protecting untrammeled nature from human activity. People were seen as a threat to wilderness and to naturalness, and isolation was regarded as the solution.
By some measures, conservationists have succeeded. There are more than 100,000 protected areas around the world, compared with fewer than 10,000 in 1950, and approximately 13% of the planet’s landmass has some form of legal protection. But we’re still losing old-growth forests in Africa, Asia and Latin America, while species are going extinct at a rate that is beginning to compare to the great die-offs of the past. Nearly one-fifth of existing vertebrate species are threatened, and if climate change continues unabated, that number will surely grow. In other words, conservationists may be winning the battle for protected areas and losing the war for wildlife.
The reality is that in the Anthropocene, there may simply be no room for nature, at least not nature as we’ve known and celebrated it—something separate from human beings—something pristine. There’s no getting back to the Garden, assuming it ever existed. For environmentalists, that will mean changing strategies, finding methods of conservation that are more people-friendly and that allow wildlife to coexist with human development. It means, if not embracing the human influence on the planet, at least accepting it.
Right now the U.S. government spends hundreds of millions of dollars a year trying to uproot invasive species like the Burmese python in Florida and the Asian carp in Illinois, desperately working to restore or at least maintain “natural” ecosystems, even though there’s growing evidence that nature is much more resilient than we have thought. As evidence, look to the ozone layer; the tear that our chlorofluorocarbons ripped in the sky over Antarctica started to shrink in 2011, years after those chemicals were phased out in most countries.
But managing the Anthropocene will necessitate more than simply banning certain pollutants or activities. It will also mean promoting the sort of technology that environmentalists have often opposed, from nuclear power—still the biggest carbon-free utility-scale energy source, despite the risk of accidents and the problem of radioactive-waste disposal—to genetically modified crops that could allow us to grow more food on less land, saving precious space for wildlife. It will mean privileging cities, because dense urban developments turn out to be the most sustainable and efficient settlements on the planet. And if we prove unable to quickly reduce greenhouse-gas emissions, we may be required to consciously fiddle with the climate through geoengineering, using artificial clouds or other planetary-scale technology to reduce the earth’s temperature directly.
Of course, humans have been effectively geoengineering the planet for centuries. We were just doing it unconsciously, as a by-product of our relentless expansion. Humans aren’t even the first species to create change on a planetary scale. The earth’s atmosphere is oxygenated because cyanobacteria helped produce that gas more than 2 billion years ago. But even though cyanobacteria weren’t conscious of what they were doing, we are, or at least we should be. Our ability to comprehend the full extent of the human impact on earth puts us in a unique position as planetary gardeners, a responsibility we have no choice but to take on. We have been lucky for much of our species’ existence, blessed by the comfortably warm climate of the Holocene, able to spread our growing numbers across a seemingly limitless planet.
But that age is over, replaced by the uncertainty of the Anthropocene, whether geologists decide to formally call it that or not. We’ll decide whether human beings continue to thrive or flame out, taking the planet down along the way. It may be an unhappy reality, because there’s no guarantee that the Anthropocene—crowded with billions of human beings—will be as conducive to life as the past 12,000 years have been. “We are as gods,” writes the environmentalist and futurist Stewart Brand. “And we have to get good at it.”
Nature Is Over, Bryan Walsh, Time, 12-Mar-2012