(Above: Coral reef at Palmyra Atoll National Wildlife Refuge. Image credit: Jim Maragos/U.S. Fish and Wildlife Service/USFWS Pacific/Flickr.)
The tropical sun rises early over Palmyra Atoll, shining light on a beautiful coral reef, a sliver of an island, and little else. Palmyra is 1,000 miles south of from the nearest major airport and city, a little speck of land in the middle of the Pacific Ocean. Signs of military activity from World War II remain — an airfield, some old buildings — but most days there are less than two dozen people on the whole island, scientific researchers there to study.
Palmyra Atoll’s remoteness was what led The Nature Conservancy and the U.S. Fish and Wildlife Service to protect it in 2000, for it has one of the most ecologically intact coral reef ecosystems in the world, with a diversity of fishes and corals that have been lost from reefs with more human activity. And yet even here, human actions have put coral reefs in danger of being destroyed. Climate change will warm ocean waters, killing many of Palmyra’s corals, and trash from all over the world washes up on its beaches. Decisions by people in Beijing or New York to drive to work will affect how many greenhouse gases are emitted, which will control the severity of climate change, which in turn will determine the fate of Palmyra.
From climate change to deforestation to water flows to soil erosion, the impacts of human actions are now having global impact. Some scientists are calling this new era of human domination “the Anthropocene.” In a recent front-page article, the Washington Post even revived Kenneth Boulding’s famous description of “Spaceship Earth,” a craft whose life-support system we must maintain if we want to survive.
Many environmentalists feel regret about the thoroughgoing way people have domesticated the natural world to suit our interests. Bill McKibben has even movingly written about “the end of nature” — at least, if “nature” is conceived as something separate and apart from people. But a recent flood of books and articles have a response to McKibben: get over it. Whether intentionally or not, these authors argue, humans are managing many of the major ecological processes on the planet.
From this point of view, what we feel morally about past human actions is irrelevant to the future. McKibben and his ilk (including me!) may mourn the disappearance of wild nature, places that are “no man’s garden” (to use Daniel Botkin’s term); while others may be indifferent to its loss.
Many of the thinkers of the Anthropocene have focused on a very important practical question: Given that we are already managing the planet’s natural systems, how can we make the domestication of nature smarter — both in the sense of increased productivity and enhanced sustainability?
Or, as Stewart Brand put is: “We are as gods and might as well get good at it.”
I spend most of my professional life as a conservation scientist working to answer pieces of this practical question, and I believe answering it is key to our civilization continuing to thrive. Our domestication of the Earth’s surface is almost certain to increase as global population and economies continue to grow and consume more resources. But in the rush to embrace better management of the planet as the new paradigm of environmentalism, we shouldn’t fail to ask a more basic question: Do we actually know enough about how nature works to actively manage many ecosystem processes — or even improve them? There’s a gradient of human control over ecosystems, from the heavily managed lawn of my apartment building to the bits of relatively wild nature like Palmyra. Even if humans are impacting every point on the Earth’s surface, our degree of management varies greatly. If we are masters of the planet, can we manage or replace everything natural?
To put it another way, humans depend on nature for a lot of things that allow them to survive and prosper. These benefits from nature are called by ecologists, rather dryly, “ecosystem services.” Some of these are tangible goods that come off managed lands, like the food we all eat. But less managed lands can be important too. Many cities depend on forests to maintain the quality of water that runs off into their reservoir, either by filtering out pollutants or by preventing erosion. If the forest wasn’t there the city could build a treatment plant to increase water quality, but at much greater financial cost. Ecosystem services can be more intangible, like the role that wild pollinators play in pollinating some food crops. In places where wild pollinators are gone, humans have stepped in as “bee wranglers” who drive around in trucks full of bee hives, providing pollination to those farmers that can pay for it. If we are planetary gardeners, do we have the technical skill to replace or actively manage all the world’s ecosystem services?
In asking that question, I should add that I reject the fundamental pessimism of some “deep” ecologists who argue that the biosphere’s exquisitely balanced processes of self-regulation could never be equaled by wise human management (or, more darkly, that human management can never be wise). I see no reason to believe that, if scientists can discover the bizarre world of particle physics and general relativity, that they cannot also discover how to sustainably manage ecosystems.
But our track record of such management thus far is not terribly encouraging.
About a decade ago, thousands of the world’s ecologists and natural resource managers came together to work on the Millennium Ecosystem Assessment. Published in 2005, the Assessment sought to quantify humanity’s dependence on ecosystem services and the trends in those ecosystem services over time. Out of 24 major ecosystem services that were examined, only nine were being used sustainably or were at least being maintained over time.
Most of these success stories were for what are called “provisioning services,” like crop and livestock production. There are strong economic incentives to manage the landscape for these services, because they often produce tangible goods that can be sold at market. While this management may not necessarily be sustainable over the long term (people tend to discount how their actions affect others, especially future generations), there is at least an economic incentive to maintain provisioning ecosystem services. Moreover, humanity has had two millennia of practice in agriculture, so it should be reassuring we have gotten better at it over time. Particularly in the last century, with the so-called Green Revolution, humanity’s ability to produce food from the land has greatly increased. Our proven technical ability to feed 7 billion people (setting aside the political obstacles to overcoming global hunger) is one of humanity’s greatest technological achievements.
That finding, however, still leaves 15 of 24 major planetary ecosystem services that were being degraded over time. Most of these are common resources, like fisheries or clean freshwater. While there are clearly examples of these kinds of common resources being sustainably used, they are in the aggregate still declining globally.
And even for those ecosystem services for which we are managing nature adequately, we are still dependent on other “regulating” services to maintain production. Without the world’s existing stock of topsoil, it would be very hard for farmers to maintain sufficient food production to feed 7 billion people. Chemical fertilizers that allow us to add the big three nutrients (nitrogen, phosphorus, and potassium) have played a crucial role in increasing global food output, but we still need natural soil.
(Above: Rainfall runoff following fertilizer applications on farm fields can cause nutrient loss, potentially polluting waterways. Image credit: pennstatelive/Flickr.)
One unintended consequence of our widespread use of chemical fertilizers is that much of it ends up in waterways. Some fraction of applied nutrients like phosphorus and nitrogen end up in plants, but much of it washes down into rivers and lakes, eventually moving downstream into estuaries. Fertilizer is relatively cheap now, and most farmers are not considered legally responsible for runoff from their property, so there is little incentive to limit excess nutrient runoff. Once nitrogen and phosphorus make their way into freshwater or marine ecosystems, they cause a massive growth of algae and other primary producers. This reduces the amount of oxygen dissolved in the water, leading to large-scale dead zones (hypoxia), where many fish species will die. Many major estuaries now have dead zones (including one at the outlet of the Mississippi that is often bigger than the state of Massachusetts). These dead zones have dramatically reduced the ecosystem services these estuaries can provide to humanity.
The basic techniques to reduce excess nutrient runoff (less fertilizer application, and then riparian buffer strips or other wetland areas that can slow the flow of water to rivers and filter excess nutrients) are well understood, but there has been little substantial progress made in stopping the slow expansion of dead zones. There are challenges at many levels that must be overcome. Scientifically, the world needs cheap yet precise ways to apply just the right amount of fertilizer at times when it is needed by the plants but when rainfall is unlikely to wash it to the sea. While such technology exists, it is far too expensive for many of the world’s farmers. Economically and politically, farmers need incentives to limit excess nutrient runoff. This has proved a hard policy task, because there are many individual actors that each contribute to the slow degradation of a common societal resource. Designing and implementing an efficient policy program to support changes in farmer practices that reduce runoff remains a challenge for humanity.
Phosphorus is actually an interesting example of a slowly emerging environmental challenge that humanity must solve. Unlike nitrogen, which we can obtain from the air, and potassium, which is abundant, the supplies of mineable phosphorus globally are limited. The United States’ supply of phosphorus, mostly from a large mine near Tampa, FL, may only satisfy our domestic requirements for a few more decades. Globally, there is perhaps a century of phosphorus supply remaining at current use rates. As this resource gets scarce, its price will increase and make new extraction of sources of phosphorus economically viable. It will also provide an economic incentive to farmers to minimize any waste in their application of phosphorus, much of which is now not absorbed by crops but washed down into streams and lakes.
It is also worthwhile to remember than in our quest to solve one environmental problem, we sometimes accidentally create another. In 1928, Thomas Midgley, Jr., and his research team finally stumbled upon a chemical refrigerant they had spent years looking for — one that could replace some dangerous chemicals currently in use in that industry which killed or maimed many workers. Even better, the chemical was so non-reactive that Midgley famously inhaled the gas at a demonstration, to prove it wasn’t dangerous. Midgley’s chemical, Freon, went on the market a few years later, introducing a new class of chemicals to the world, chlorofluorocarbons (CFCs). The rest is history. It took decades before scientists realized that CFCs could remove the Earth’s ozone layer, essential for life’s persistence, through a chemical reaction in the stratosphere.
If we are as gods upon this Earth, then we are peculiarly bumbling gods. Perhaps we are like the classical Roman gods, blessed with power but (for now at least) full of ignorance.
Reverse engineering a flying spaceship
On September 26, 1991, eight people shut the door inside a huge, 3-acre enclosure, complete with replicas of a working rainforest and coral reefs. The goal of Biosphere 2 was simple: see if people could maintain a self-sufficient, enclosed ecosystem for any length of time. Biosphere 1, in case you’re wondering, is the Earth itself. The base was initially well stocked with the plants and animals that people would need to survive. Nothing, not even air, was to go in or out. For 2 years, the people inside Biosphere 2 were to be self-sufficient.
(Above: Biosphere 2 panorama. Image credit: PurpleGecko/Flickr.)
The mission was ultimately a failure for a complex set of reasons, about which whole books have been written. For one thing, the crew never managed to produce enough food, lost a great deal of weight, and eventually had to be fed supplemental food from outside Biosphere 2. A few invasive plants and animals exploded in population, causing more problems. “I didn’t expect the cockroaches,” said Jen Molnar, currently the director of the Conservancy Sustainability Science Team, who worked as a lab tech in Biosphere 2 several years later when the facility was transitioning to being a traditional scientific research site. “They were so thick they would cover the wooden walkways and you couldn’t walk without stepping on them.”
The biggest issue from the standpoint of human health was the wild swings in carbon dioxide and oxygen levels in the atmosphere. Big chunks of soil had been imported whole into the site, and the organic matter within them was decaying, releasing carbon dioxide. At the same time oxygen was being slowly absorbed into Biosphere 2’s concrete walls, an event that seemed obvious in hindsight but was not expected by the engineers planning the mission — unlike Biosphere 2, most normal buildings intentionally allow external air in for ventilation, so this phenomenon is not something that is usually a problem. Even when Molnar worked at Biosphere 2 years later, workers had to sign a waiver acknowledging they knew about the abnormally high carbon dioxide levels. “I asked how high the levels got and the woman hiring me just laughed and shrugged,” said Molnar.
In many ways, Biosphere 2 is an imperfect example of human’s capacity to manage the Earth. There were some disastrous personality clashes during the project, and an odd “survivalist” mentality that permeated the whole mission. Some of those involved saw the world as quickly heading toward an ecological catastrophe, and wanted to create something like Noah’s Ark, an encapsulation of complete ecosystems. Moreover, it has been 20 years, and ecosystem science has advanced significantly. It would be extremely interesting to create Biosphere 3, as a rigorous scientific and engineering experiment to fully sustain humans in a totally contained space for a set period of time. Such an experiment could provide lessons for ecosystem science as well as for space programs like NASA that might someday have to set up long-term bases on another planet.
Apart from the specific problems of the Biosphere 2 mission, which were legion, the overall conclusion is clear: humans are very far from being able to fully replace, or even maintain, everything they need from the natural world. For all of humanity’s knowledge about nature, and for our enormous increase in the power we can exert over the natural world, we can still only at best partially manage and maintain Spaceship Earth. Instead of being the proud commander of Spaceship Earth, we are more like Chewbacca in Star Wars, pounding the walls of the ship in hopes it will continue to go. It’s not enough for those who write about the Anthropocene to say to humanity “get over it” and accept the mantle of global stewardship. In the Anthropocene, the real challenge for the world’s scientists is: get working, and quickly fill in our considerable gaps in knowledge and practice. We have to get much, much better at managing and maintaining the only spaceship we’ve got, if we hope to continue on our species’ voyage.