Our planet has suffered five mass extinctions, the last of which occurred about 66 million years ago, when a giant asteroid believed to have landed near the Yucatán Peninsula set off a chain reaction that wiped out the dinosaurs and roughly three-quarters of the other species on earth. A few years ago, in a book called “The Sixth Extinction,” the writer Elizabeth Kolbert warned of a devastating sequel, with plant and animal species on land and sea already disappearing at a ferocious clip, their habitats destroyed or diminished by human activities.
This time, she made clear, the asteroid is us — and we will pay heavily for our folly.
Humanity’s culpability in what many scientists believe to be a planetary emergency has now been reaffirmed by a detailed and depressing report compiled by hundreds of international experts and based on thousands of scientific studies. A summary was released last Monday in Paris, and the full 1,500-page report will be available later in the year. Its findings are grim. “Biodiversity” — a word encompassing all living flora and fauna — “is declining faster than at any time in human history,” it says, estimating that “around 1 million species already face extinction, many within decades,” unless the world takes transformative action to save natural systems. The at-risk population includes a half-million land-based species and one-third of marine mammals and corals.
Most of the causes of this carnage seem familiar: logging, poaching, overfishing by large industrial fleets, pollution, invasive species, the spread of roads and cities to accommodate an exploding global population, now seven billion and rising. If there is one alpha culprit, it is the clearing of forests and wetlands for farms to feed all those people (and, perversely, to help them get to work: The destruction of Indonesia’s valuable rain forests, and their replacement with palm oil plantations, has been driven in part by Europe’s boundless appetite for biodiesel fuels.)
Add to all this a relatively new threat: Global warming, driven largely by the burning of fossil fuels, is expected to compound the damage. “While climate change has not been the dominant driver of biodiversity loss to date in most parts of the world, it is projected to become as or more important,” said Sir Robert Watson, chairman of the biodiversity panel and former chairman of the United Nations Intergovernmental Panel on Climate Change, whose most recent alarming report on global warming has given that issue new currency in American politics. Rising seas and increased extreme weather events propelled in part by climate change — fire, floods, droughts — have already harmed many species. The most obvious victim is the world’s coral reefs, which have suffered grievously from ocean waters that have grown warmer and more acidic as a result of all the carbon dioxide they’ve been asked to absorb.
As The Times’s Brad Plumer recently noted, many ecologists insist that species are worth saving on their own, that it’s simply morally wrong to drive any living creature to extinction. The new report deliberately adds a powerful practical motive to the spiritual one: Biodiversity loss, it says, is an urgent issue for human well-being, providing billions and billions of dollars in what experts call “ecosystem services.” Wetlands clean and purify water. Coral reefs nourish vast fish populations that feed the world. Organic matter in the soil nourishes crops. Bees and other threatened insects pollinate fruits and vegetables. Mangroves protect us from floods made worse by rising seas.
“Most of nature’s contributions are not fully replaceable,” the report says. But humans can stop or at least limit the damage. One critical task is to protect (and if possible to enlarge) the world’s natural forests, which, according to a recent paper by eminent ecologists in Science Advance, are home to fully two-thirds of the world’s species. Intact forests also absorb and store enormous amounts of carbon, so preserving them assists not only the species that live there but also the struggle against climate change. Conversely, cutting trees to make way for farming and other purposes — as Brazil’s president, Jair Bolsonaro, is determined to do in the Amazon — is a disaster for both the species and the climate; recent estimates suggest that deforestation accounts for slightly over 10 percent of worldwide greenhouse gas emissions, much smaller than the emissions from vehicles and power plants, but significant (and avoidable) nonetheless.
To Professor Watson and many other scientists, there are two important parallel approaches to the interconnected climate and species crises. One is to transform agricultural practices, the other is to enlarge the world’s supply of legally protected landscapes that cannot be touched for any commercial purpose. As to the first, farmers could figure out how to produce more food on fewer acres, and in ways that help the soil retain carbon; consumers could help by making smarter food choices, like eating more locally sourced food, and cutting back on meat and dairy products that require immense amounts of land for livestock.
Second, governments should mandate a significant increase in protected areas, both on land and at sea. Partly as a result of the Convention on Biological Diversity, a treaty agreed upon in 1992 in Rio de Janeiro along with a landmark agreement on climate change, nations have set aside about 15 percent of the world’s land and 7 percent of its oceans by setting up wilderness areas and nature preserves. Because this is only a fraction of the areas needed to protect biodiversity, the authors of the paper in Science Advance recommend a twofold increase in the protected land area and a fourfold increase in marine reserves over the next decade. If rigorously policed (which many parks are not today), that would effectively quarantine about 30 percent of the world’s land and oceans.
This proposal, which its authors call a Global Deal for Nature (echoing the Democrats’ Green New Deal on climate), will be further refined before the next meeting of the parties to the Convention on Biological Diversity in 2020 in China. Though it always sends a delegation to these meetings, the United States has never ratified the treaty; President Bill Clinton signed it in 1993, but the Republican Senate failed to ratify it for various reasons, including unfounded fears that the treaty threatened American patent and intellectual property rights.
It is hard to believe that the Trump administration and the current Senate will be any more enthusiastic about preserving biodiversity than the Senate was then. This is an administration, after all, that has proposed to shrink national monuments and reduce protections for the imperiled sage grouse in order to accommodate the oil, gas and coal industries; that is moving to open up the species-rich coastal plain of the Arctic National Wildlife Refuge to drilling; that plans to make available now-protected waters along America’s Pacific and Atlantic coasts for the same purpose; that proposes to sacrifice parts of Alaska’s Tongass National Forest to logging; that, most tellingly, aims to weaken the Endangered Species Act, approved in 1973 with Richard Nixon’s signature in what seems a distant era when there was fairly deep bipartisan support for environmental values.
Few of the Democratic presidential hopefuls who have spoken about climate change and jumped with varying degrees of enthusiasm on the Green New Deal bandwagon have commented on the biodiversity report, despite biodiversity’s obvious connections to climate. They should read it, and make it part of their post-2020 agenda.
More on the loss of biodiversity