Earth in Human Hands Page 13
You cannot become aware of global problems, of your own global role, or think about responding globally until you know that you live on a planet and are able to observe and study its changing properties. For us these realizations required very sophisticated scientific knowledge, including space-based sensors, which could not have been built without the bootstrapped explosions in knowledge and innovation of the scientific and industrial revolutions. We could not really see our world, wholly and clearly, until our transformation of it was already well under way.
In planetary changes of both the third and fourth kinds, the world is changing through cognitive processes. Both involve intention, enabled by its great force multiplier, technology. Intentional actions require forethought, internal mental pictures of a future state that one’s actions may bring about and, often, the ability to communicate this vision to a group and plan collectively. These are capabilities that have quite recently appeared in Earth’s biosphere. Later I will parse this a little more carefully, taking up the question of what it means for a species to evolve these abilities, but for now, suffice it to say that this is a kind of activity that bacteria, fleas, and sea slugs do not undertake but that human beings do, and one that is quite clearly changing the world. So this qualifies as a new kind of planetary change, one that Earth has not encountered before.
What do I mean by technology? The invention and use of tools to enhance one’s ability to affect one’s environment. With technology we transcend the physical and temporal limitations of our individual bodies, changing our environment by building “extrasomatic” (beyond the body) structures, including information storage that allows us to accumulate knowledge, recording and passing on stories, lessons, and plans. From stone chips to silicon chips, we’ve extended our reach, moving and shaping our surroundings with greater distance, force, and persistence than can be achieved with teeth, skin, muscle, and bone.
Key here is not simply the existence of intentionality, but the physical scale at which the consequences of intentional actions play out. Earlier I said that the cyanobacteria changed the world “unwittingly.” Neither the third nor the fourth kind of change can be called “unwitting,” as each arises from awareness and intention, manifesting at different levels and scales.
Consider the traffic at rush hour on Interstate Highway 10 through Los Angeles. You have many individuals acting to solve their own problems, such as how to get from Pasadena to Venice Beach without, at least until recently, much awareness of the cumulative, global effect of their actions. Each driver is at the wheel of their own car, capable of applying feedbacks, making course corrections to avoid problems. All are participating in a massive system of cooperative collective activity that, despite our obligatory bitching and complaining, actually works fantastically well. Collisions and acts of road rage are rare, even in California. Yet who is driving the global transportation system, applying feedbacks and making course corrections? Nobody? Or perhaps “the market,” that metaphysical beast whose emotions, thoughts, and decisions we hear about daily in meta-metaphorical attempts to describe our collective actions to ourselves. To the extent that this system can be said to be under conscious control, it is an entirely different sort of consciousness than we each possess individually.
We have individual agency, and we have limited collective agency—that is, we have the ability to plan and act in groups. Indeed, this is perhaps the hallmark of our species. Yet we also act on scales beyond which we have any obvious agency. On a global scale, we watch, discuss, and describe our actions as if from a distance, seemingly unable to stop, change course, or control ourselves. And as we start to become aware of the multigenerational consequences of our actions but act largely without any long-term plan or sense that we can enact one, it is almost as if we are observing someone else doing these things. It’s like a disconcerting dream where you see yourself running toward a cliff or committing a crime, but you can’t do anything to stop yourself. There is certainly intentionality in the human actions that are causing planetary-scale changes, but it exists almost entirely at much smaller spatial and temporal scales than those at which these effects play out.
It is this combination of local technical success with global obliviousness that defines planetary changes of the third kind, or inadvertent catastrophe: that is, planetary-scale changes that result from intentional applications of technology but are not themselves intended.
As we become aware of the planetary consequences of our activities, but still lack any sense of direct control over them, we find ourselves in a dilemma. We knowingly use our technology on a scale that is changing the world, yet we have no global sense of intentionality. This is what I call the Anthropocene dilemma.
Planetary Changes of the Third Kind: Inadvertent Technological Catastrophe
And now the world is ours—or at least our responsibility. As those department store signs say, “If You Break It, You’ve Bought It.” Whether we like it or not, whether we deserve or can handle this responsibility—these are separate questions—somehow, without realizing it, we have assumed it. Human influence has taken firm hold of Earth, and letting go is not an option. There is no doubt that we have entered a new geological time period with a new type of force simultaneously upsetting multiple Earth systems. The case for anthropogenic global warming has been made. I don’t feel that I need to waste a whole lot of ink laying out the evidence. It’s been done well elsewhere, and it’s not my purpose here to convince the holdouts, but rather to try to move the conversation along. Global warming is just one of many disturbances. Discussions framed around the Anthropocene epoch are broadening to include a wide array of anthropogenic changes. I’ll offer a summary here, but from a planetary history point of view, there is no question that the Anthropocene reworking and reshuffling of Earth is rapid and extreme enough to be called a catastrophe.
We have all heard by now that we’ve pushed atmospheric CO2 to dangerously high levels. You’ve seen the now-iconic graph of carbon dioxide ascending, oscillating through the seasons, but inexorably rising over the years. This, perhaps the most recognizable, frightening, and convincing diagram in all of earth science, is called the Keeling curve, after Charles David Keeling, who in 1958 somewhat quixotically began monitoring airborne carbon dioxide from Mauna Kea, in Hawaii. Over the intervening decades, up to his death in 2005, he staunchly maintained a continuous set of observations that allowed us to see what we are doing with stark clarity. After just a few years the emerging pattern in Keeling’s curve was key to getting scientists to realize that human industrial intervention really was changing our atmosphere at an accelerating rate. Now it has become key for our efforts to communicate this reality to everyone else. Keeling’s measurements started a year before I was born (in 1959). Since then, the amount of CO2 has risen by almost 30 percent. That’s not a tweak; it’s a jolt.
The Keeling curve shows CO2 rising steadily over recent decades.
Our planet has not experienced four hundred parts per million of CO2 for almost two million years. The details of our ancestry are still being worked out, but it seems that the last time there was this much greenhouse warming, some of the first humans (that is, members of the genus Homo) had recently appeared on Earth. These Homo habilis were using early stone tools along the drying rivers and spreading savannahs of East Africa as the climate warmed. Anatomically modern Homo sapiens first appeared in East Africa around three hundred thousand years ago. Nobody from our species has ever breathed air as thick with CO2 as we do today.
Certainly if you look back in geological history you can find plenty of times when our planet had more carbon in the atmosphere. Yet it has rarely, if ever, in its entire 4.5-billion-year history, experienced the rate of atmospheric change we are inducing, in confluence with such a wide suite of other provocations, to the land surface, to the oceans, to the hydrological and biogeochemical cycles. When you study Earth’s deep history, this convergence of changes at accelerating rates is what truly stands out about our time.
Together, they represent an unprecedented challenge to the Earth system. The fact that the planet has never experienced anything like this limits the utility of the geological record for making detailed predictions. Still, we can safely predict some general consequences. Already we observe, in addition to the warming of the planet, a rapid loss of sea ice, the retreat of glaciers, rising sea level, wholesale migrations of species to higher latitudes, and large-scale deviations in precipitation patterns and ocean chemistry.
Despite popular assertions to the contrary, none of this climate change is permanent. Not on Earth time. Human time, you might say, is a different story, but our new awareness of the Anthropocene is forcing a reckoning between these two timescales. Some changes may seem “permanent for all practical purposes,” yet when we make this distinction, we are removing ourselves from geological time. We need to start doing the opposite: seeing ourselves within the spatial and temporal landscape of the planet we inhabit, especially as, increasingly, we do more than just inhabit Earth.
Earth does, in fact, have natural buffers and correction mechanisms that, eventually, will push back and fix atmospheric imbalances. These systems are now being temporarily overwhelmed by our relentless industrial emissions. Over many millennia, these insults will gradually be corrected by slow but inexorable planetary cycles. The environmental perturbations we are causing will not be permanent, but the extinctions we are causing will be. Other signs of our having been here will also persist for as long as Earth lasts. We are now a part of Earth’s geological record.4 No matter what we do, no matter where we go from here, we have left our mark. One of those indelible signatures will be the sudden disappearance of certain fossils. Barring some determined intervention, CO2 will remain at elevated levels for about one hundred thousand years. In addition to the direct climate effect of its infrared absorption, it dissolves in ocean water and creates carbonic acid, which corrodes shells and reefs. This acidification of Earth’s oceans seems, by now, inevitable.5 We can change course, save our civilization, limit the harm to vulnerable peoples, and rescue many species that are currently threatened, but much damage has already been done. I’m afraid we may lose our coral reefs.
Slightly comforting, perhaps, is the knowledge that over the ages our planet has lost its reefs several times. During ancient episodes of high CO2 and ocean acidification, the magnificent coral conurbations have disappeared entirely—and then somehow have returned. So it may be that, even if they are soon dissolved by our short-sightedness, in a million years Earth will once again have great barrier reefs. Yet our great-great-grandchildren may know them only as curiosities in natural history museums.
Other greenhouse gases are also being forced to unnatural levels, the most notable being methane from intensive agriculture: the flatulence of cattle and the bacterial burps of rice paddies. Yet atmospheric change and global warming are only the most well-known examples in an array of accelerating planetary provocations. They’re the ones that have gotten our attention, but there are many others. The carbon cycle has grabbed the headlines, but we’ve also seized hold of many other major geochemical cycles. Through production of fertilizers, we’ve radically altered Earth’s nitrogen cycle. The sulfur cycle has become dominated by industrial emissions. We’ve dammed rivers so thoroughly that there is now more than five times as much fresh water captured in reservoirs as there is remaining in all the wild rivers and streams of Earth! That is not a minor change. It’s fair to say that we’ve domesticated a major part of the water cycle of this planet. Earth’s vibrant hydrosphere, arguably our planet’s most distinctive feature, has to some degree become an artifact of human civilization.
Every year now, humans constructing roads, buildings, and farms displace ten times more dirt than the combined erosive forces of wind, rain, earthquakes, and tides. Simply measured by the amount of stuff we move around, we have become the undisputed world heavyweight champions of change.
The sky itself has been altered, muted. Those same spreading lights that, seen from space, mark our age as different, also, here on the ground, fill our nights with scattered artificial illumination. Ironically, in this age when we’ve finally figured out what the stars are and where we stand in relation to them, we’ve also distanced ourselves from the direct experience of them. Yet we and the stars go way back together. We’re made of stellar remnants and ashes, and as long as we’ve been human they’ve guided and inspired us, served as compass, calendar, and clock, oriented us in our wanderings as we peopled the continents and crossed the seas. Even now our interplanetary spacecraft use star sensors to find their way. The stars have humbled us with their beauty and filled us with curiosity and wonder. Yet as we haphazardly spill light from our mushrooming cities and roads, we carelessly push back the night. We’ve so intensively urbanized our populations that, for most of us, the stars have largely receded from view. I’ve heard it said, and it may be true, that for the first time ever the majority of children being born today will never in their lives directly see the Milky Way galaxy. The cosmic connection has never been closer or more remote.
Age of Plastic
We’ve created major new geographic features of this planet, including the Northern Pacific plastic gyre, otherwise known as the Great Pacific Garbage Patch. This semipermanent vortex of debris comes from partially decayed plastic toys, trash, and manufacturing products washed out of storm drains and into the coastal waters of Japan, the United States, and farther afield, gathered and trapped by the ocean currents and winds, extending over an area that is larger than the United States. There’s a nearly mythical quality to this structure. For so long we imagined that the world, and in particular the ocean, was infinite. Even when we knew it wasn’t, literally, we still fancied it was so large that we could just throw stuff away and it would disappear.* We never worried about where “away” was. There was a time when our numbers were sufficiently few and our construction materials so impermanent that the things we threw away really did disappear into the cyclic reclaiming and repurposing of Earth and its biota. This is no longer the case. We’ve found out where “away” is. It is, of course, many places, but some of what we throw there ends up in a giant gyre in the Northern Pacific.
In the previous chapter, I recount how the takeover of Earth by life introduced a plethora of new materials here not found on dead worlds, including the majority of minerals in the crust. Now this new global force, the influence of mind and technology, has again flooded the planet with novel substances.6 We’ve created newfangled materials that are rapidly becoming integrated into Earth’s oceans, landscapes, ecologies, and rock cycle. My friend Odile Madden, a materials scientist, is fascinated by plastic. Not like the guy in The Graduate (whom she is so sick of hearing jokes about), but as principal investigator for the Age of Plastic research program at the Smithsonian’s Museum Conservation Institute. She is also part of our informal “Washington Anthropocene Group,” a semiregular gathering of like-minded folks I first convened at the Library of Congress, where she regales us with tales from the age of plastic. She’s convinced me that plastics make a great proxy for tracking the human influence on Earth in the Anthropocene age.
Plastics are synthetic polymers that were created early in the Industrial Revolution and began to abet and replace naturally occurring polymers such as cotton and rubber. Polymers are long-chain molecules, usually based on carbon. If that sounds familiar it’s because that is basically what we terrestrial creatures are, inasmuch as proteins and DNA are themselves long-chain carbon molecules. Yet our proteins work by being modular, flexible, and loose. They fold into intricate 3-D sculptures whose complex shapes run our internal chemical factories by controlling their interactions with the other molecules in our cells. Plastic polymers have rigid, repetitive structures that make them, as molecules, too inflexible for biology but, as materials, stronger and more versatile than living tissues. So we, watery cells of folding, mutable long-chain carbon molecules, have discovered, invented, and refined these materials made of l
ess flexible carbon chains, and have used them to extend our reach into the world.
At first we made them from modified natural materials, but later primarily as synthetic petroleum products. When we started using them we didn’t have a long-term plan for what would happen to them. Why should we have? We never had a plan for rock, wood, or steel, which we just left to erode, rot, or rust in place. Who ever thought that the world would start to fill up with our stuff? After World War II, manufacturing techniques perfected for wartime production were used to produce a profusion of new industrial and consumer products, and as with so many other Anthropocene signatures, their use exploded around 1950, and our plastic things started to pile up by roadsides and in landfills and to drift across the seas.
We often use the word plastic as a synonym for cheap, fake, or insubstantial, but Odile, in her talks, reminds us of the many ways it has made our lives better. One small but hugely significant example she cites is in the area of medical technology, where plastic products such as blood bags for IVs and inexpensive syringes have helped to spread affordable and sanitary medicine throughout the world. As Odile puts it, we have a love/hate relationship with plastics. We’re repulsed by the way they are accumulating in wild places and animal guts, yet we would never give up all the benefits they provide.
Odile thinks we are still in the early part of the plastic age. She reminds us that other ages defined by materials (the Bronze Age, the Iron Age) lasted a lot longer than this, and that we are still on a learning curve, figuring out how to use them well. She and her colleagues have gone on research expeditions to study the plastic debris washed up on the remote Alaskan coastline, analyzing the composition and figuring out the sources. There they find massive amounts of derelict fishing gear, packing and construction materials, and random consumer items (little orange Nerf balls and fake flowers for hummingbird feeders), largely from container ship spills. On one beach they found hundreds of NFL team fly swatters, made in Asia, destined for American markets. Though this sounds dismal, Odile adds, “What we didn’t see was Alaska clogged with plastic. Nature was much bigger than the garbage, which felt very good.”