It is rare for life to change Earth, yet three organisms have profoundly transformed our planet over the long course of its history. Elemental reveals how microbes, plants, and people used the fundamental building blocks of life to alter the climate, and with it, the trajectory of life on Earth in the past, present, and future.
Your book, Elemental, is sectioned into three parts: past, present, and future. Given how unique humans seem to be, what can the geologic past tell us about our modern environmental woes?
SP: Humans are unique in some ways, but there are organisms that preceded us who have made massive environmental changes to the planet. These life-driven changes are really rare in Earth history, occurring a few times in the four-billion-year history of life on Earth. But what鈥檚 fascinating, and helpful for understanding our present environmental challenges, is that each time an organism evolves to profoundly change the world, the mechanism by which they do so is remarkably similar. Elemental explores our similarities to our world-changing predecessors.
Here’s an example. The biggest environmental change of all time was the oxygenation of our atmosphere. The change was precipitated by a group of single-celled organisms called cyanobacteria about 2.4 billion years ago. They made Earth the only known planet in this solar system, or any solar system, that has breathable oxygen in the atmosphere. How did the cyanobacteria pull off this planetary alchemy? They combined a new way of capturing energy with a better way of feeding themselves, which allowed them to wildly proliferate, and increased the total amount of life on Earth by ten-fold or more.
That in itself is a big change. But the cellular chemistry they evolved to pull of this remarkable population boom had a waste product, oxygen, that they dumped into the ocean. After a while, likely hundreds of millions of years, enough oxygen accumulated to bubble out into the air. That oxygen altered the chemistry of the atmosphere so profoundly, and particularly changed the greenhouse effect so profoundly, that it precipitated catastrophic climate change.
Let鈥檚 compare that story to the story of human impact. We鈥檝e found and exploited a 鈥渘ew鈥� source of energy in fossil fuels 鈥� in quotes because coal, gas and oil are simply the concentrated remains of ancient living things. We鈥檝e revolutionized the way we grow food, in fact in a very similar way to what the cyanobacteria did. And the chemical waste products from these innovations are changing the Earth鈥檚 greenhouse effect, the climate, and the living systems that depend on it. So yes 鈥� we are unique in some ways. But maybe not as unique as all that.
Your book argues that sustainability can be centered around five chemical elements - hence the title Elemental. Why these five?
SP: Our world is so diverse 鈥� millions upon uncounted millions of species from microbes to blue whales. But all of us, every single living thing, is built from the same elements. In order of abundance, they are the five of the book: hydrogen, oxygen, carbon, nitrogen and phosphorus. For all the. Complexity of life, all the predator/prey interactions, symbiotic relationships between hummingbirds and flowering plants, parasitic relationships between worms and dogs, we are all doing essentially the same thing. We鈥檙e trying to gather these five elements (and a few more) from our environment. Plants do it by using the energy of the sun to capture carbon from the air, and use that carbon to grow roots that gather water (hydrogen and oxygen), nitrogen and phosphorus from the soil. Animals get their elements from eating plants (or other animals) and drinking water. Life is a relentless quest for these five elements, and viewing it through this lens is a powerful organizing principle in my field of biogeochemistry.
But that鈥檚 only half the reason I focus on these five elements. Four of them, all but phosphorus (I hope you read the book to see why phosphorus is also critically important), also make up the greenhouse gases that control Earth鈥檚 climate. That means that the availability of these elements limits how much life there is on Earth. It also means that when evolutionary leaps occur that allow a group of organisms to gather enormous new quantities of these elements, it can change the chemistry of the air and water, and that has profound consequences for all living things.
Linking back to the first question 鈥� the first world changing organisms, the cyanobacteria, changed the world largely because they combined new ways of getting carbon and nitrogen. The second, the land plants, evolved new ways of getting hydrogen and oxygen (in water) and phosphorus. The third, humans, have built our world-changing prowess by innovations in all five. It is no surprise we are changing the world.
One of the things that makes humans unique is our ability to alter the global flows of all of these elements, and to do so at an unprecedented pace. Can you give us a sense of just how 鈥渦nprecedented鈥� we actually are?
SP: We are unprecedented in the pace of change we are driving. It took the cyanobacteria hundreds of millions of years to change the world, although the change they wrought was way bigger than anything humans will ever bring about. Similarly, land plants, which I haven鈥檛 talked about much here but which are a big focus of the first part of the book, took almost a hundred million years for their impacts to truly go global. They pulled so much carbon dioxide out of the air as they proliferated across the continents that they took the planet from a global hothouse to an ice age, but again that took tens upon tens of millions of years. Humans haven鈥檛 changed the atmosphere as much, yet, but what we鈥檝e done we鈥檝e done in about 150 years, and most of that in the last few decades. We have become a living geologic force, but we鈥檙e moving at the speed of life. That鈥檚 unique, and, honestly, pretty scary.
If someone wants to make a few changes to the way they live their daily lives, which will have the biggest impact, and which ones should they not worry so much about?
SP: This is a big question, and my answer may differ from some of my colleagues. I think people worry about too many things when it comes to the environment and sustainability. In so doing, they often focus on the ones that are easy rather than the ones that are impactful. The example I give is driving an SUV to get a gallon of organic milk. You feel good about buying organic, but making an extra trip in an SUV is way, way more impactful (in a bad way) than the benefit of the organic milk. Even worse, milk is one of the worst food products you can buy if you鈥檙e worried about climate change because cows are a huge source of greenhouse gasses, not to mention nitrogen and phosphorus pollution and water consumption.
So, what should people do? First, focus on climate change. It is the biggest environmental issue of our times, indeed of any time in human history. For the average American, two of the biggest sources of emissions are heating your house and transportation. Electrify both. Get an electric car as soon as you can, and get rid of your furnace and replace it with heat pumps, which provide hyper efficient heating and cooling that is powered only by electricity. If you can put up solar panels on your house to make that electricity, wonderful. If you can鈥檛 your utility probably offers a 鈥�100% renewable鈥� package for your electric service, and if not there may be 鈥渃ommunity-based solar鈥� options available. Sign up. For the average American those two things will reduce your carbon footprint by at least half, unless you fly a lot.
Those changes will have the biggest benefit for your carbon footprint. A few more tips 鈥� when you replace your appliances go with Energy Star, get a front loading rather than top loading washer. If you want to deal with the other elements, reduce your red meat (including pork) and dairy consumption. Most nitrogen and phosphorus related problems are because of fertilizer pollution, and cows, lamb and pigs are a big part of that problem. This will also lower your carbon footprint, since cows are also the number one source of greenhouse gas emissions from the food production system.
Lastly 鈥� vote. Talk to people in your community, whatever community it is, and see where you can find common ground. Discuss how we can get the things we need 鈥� energy, food, water 鈥� without profoundly disrupting the global flows of these life-giving necessities. No one wakes up in the morning wanting to destroy the future, so chances are if you don鈥檛 agree it isn鈥檛 because you have wildly different goals. Try to keep an open mind and heart and work for positive change.
We live in an era of unprecedented environmental challenges and anxiety, but I’ve seen your book described as 鈥渙ptimistic鈥�. Why are you optimistic?
SP: Ten years ago, if you had asked me how much warmer the planet would be by the time my teen-aged daughter is a grandmother, I would have said about 8掳F. Now I think that number is likely to be closer to 5掳F warmer. Neither number sounds big to the average person, after all a single day sees bigger changes. But, to those who study climate know that the difference between an ice age and the warm period we鈥檙e in now is about 8掳F. So going from 8掳F to 5掳F warmer is a very hopeful step! 8掳F warmer would be a world that is virtually unrecognizable. 5掳F will still be very tough, but I鈥檓 convinced we can get that number lower.
Why am I convinced? Most of what we need already exists, and is gaining speed. We鈥檝e underestimated how fast we would respond to this challenge, but I also think we underestimate how fast we can move once things get going, as they have now. Solar is the cheapest form of electricity in almost every economy in the world. Electric cars drive better, and cost less to own, than gas cars. Soon they will be cheaper to buy as well. And even if you power your electric car from a grid that depends on fossil fuels, lifetime emission from an eV will be 75% lower than from a gas car. As the grid gets greener, your eV will get cleaner. The same is true for an all-electric house that uses heat pumps to heat air and water.
Changes in agriculture, and new technologies for carbon capture and storage, mean we even have a chance to initiate global cooling by the latter half of this century, and (maybe) pull ourselves back into a safe climate space. It鈥檚 not guaranteed, but it鈥檚 possible, and there are millions of smart, motivated people working really hard to make that happen. And whether or not you鈥檙e a big fan of capitalism, lots and lots of capital is flowing towards these challenges, with huge economic rewards awaiting the most effective innovations. That鈥檚 reason for cautious optimism as well, though we all know that capitalism and profit motivation is a double edged sword.
Finally, we humans are beginning to think of the Earth as a system, in which we play a critical role as a world changing organism through the management of life鈥檚 essential elements. We alter their global rhythms. So far, we鈥檝e done that by neglect, and management by neglect is never a wise strategy. But there is nothing to prevent us from bringing intentionality and purpose to our elemental interventions to build a better future.
Stephen Porder is associate provost for sustainability and professor of ecology, evolution, and organismal biology at Brown University. He is also a fellow in the Institute at Brown for Environment and Society. His writing has appeared in the New York Times, Natural History, and other leading publications. He is cofounder of Possibly, which airs on The Public鈥檚 Radio and provides practical advice on sustainability to a general audience.