How Will Climate Change Affect Our Future? Lessons from Earth’s 5 Vital Elements

Can We Stop Global Warming? What Ancient Bacteria Teaches Us About Survival

Discover how hydrogen, carbon, and three other elements shaped Earth’s past—and why balancing them is crucial for humanity’s survival. Read our deep dive into Elemental by Stephen Porder. Ready to understand the chemistry behind our planet’s future? Scroll down to discover how these five invisible forces control everything from ice ages to your next meal.

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What do single-celled bacteria, Earth’s first land plants, and humans have in common? They’re all “world-changers,” according to Stephen Porder, a professor of ecology and evolutionary biology at Brown University. Learn how these life forms dramatically altered the course of planetary history by shifting the delicate balance of the five key elements: hydrogen, oxygen, carbon, nitrogen, and phosphorous. As Porder explains, by looking at the past — and the impact of organisms on the planet over billions of years — humanity can better plan for the future, as people react to climate catastrophe and protect the well-being of future generations.

Take-Aways

• Five key elements combine to create life, but changes in their ratio dramatically alter planetary history.
• Single-celled bacteria triggered Earth’s first ice age, during the “Great Oxidation Event.”
• Prehistoric plants dramatically altered Earth’s geology, triggering the creation of carbon-storing limestone.
• Merging slow and fast carbon cycles by burning fossil fuels speeds up global warming at unprecedented rates.
• Humanity needs to reduce reliance on carbon and nitrogen to prevent catastrophic global warming.
• Phosphorous is needed to sustain life — and it’s in scarce supply.
• Irrigating dry regions can increase soil salinization and ultimately kill crops.
• Humanity must radically rethink its approach to agriculture, reducing production of red meat.

Summary

Five key elements combine to create life, but changes in their ratio dramatically alter planetary history.

While humans are certainly a “world-changing” species, they’re not the first to dramatically alter the course of planetary history. Before humans, there were single-celled cyanobacteria and prehistoric plants that first colonized dry land — both of which triggered ice ages on Earth billions of years ago. However, the biggest factors that enabled these organisms to create change at a massive scale were five elements: “hydrogen (H), oxygen (O), carbon (C), nitrogen (N), and phosphorus (P).” These elements are significant because they make up “Life’s Formula,” or “HOCNP,” as every organism on Earth engages “in a relentless search for these elemental ingredients, gathering them from the environment to build their bodies.” The species that manage to secure the right ratio of these elements needed to sustain life survive, while those that fail to do so perish.

“Humans are now a dominant geologic force for the global cycles of the elements that change the world. I don’t know whether we will act on what we can learn from our predecessors and avoid the worst consequences that come with changing the world.”

If you were to analyze the chemical components of humans and cyanobacteria, you could write them out with two different chemical “formulae,” using the same five elements (and in the case of humans, one other — calcium) as follows: Cyanobacteria can be represented by: H263O110C106N16P1, while humans can be represented by: H375O132C88N6Ca1P1. These “formulae” are approximate ratios (human cells are composed of thousands of chemicals, and the subscripts below the chemicals, which represent the total number of atoms, have been reduced), but demonstrate the chemical similarities between two life forms that seem vastly different — and all life forms for that matter. Every living organism on Earth needs access to all five elements to stay alive.

Single-celled bacteria triggered Earth’s first ice age, during the “Great Oxidation Event.”

The five elements in Life’s Formula play a vital role in the chemical processes that influence Earth’s atmosphere: As human activity contributes to the emission of greenhouse gases like carbon dioxide, the delicate balance of Life’s Formula gets disrupted, triggering profound environmental challenges, while exacerbating the impacts of climate change on Earth’s ecosystems. Human activity is already altering the factors that influence this balance, making it imperative for humanity to learn from past world-changers and avoid creating atmospheric shifts that render life untenable.

One powerful example is cyanobacteria, which introduced oxygen into Earth’s atmosphere, precipitating the “Great Oxidation Event”— one of the most dramatic evolutionary shifts that ultimately triggered an ice age.

“If an organism evolves a way to alter the flows of even a few of the five elements in Life’s Formula, they can proliferate. Because those elements are also tightly linked to climate, a change in this flow can change the world.”

Over three and a half billion years ago, cyanobacteria developed an enzyme that gave them the capacity to break apart nitrogen (N2), which was inaccessible when bonded as a pair of atoms, and fix it as a single atom. Cyanobacteria also developed the ability to perform photosynthesis, converting carbon dioxide and water into sugars while releasing oxygen as a byproduct. This led to the proliferation of cyanobacteria in Earth’s oceans, flooding the atmosphere with oxygen, which destroyed the methane that had been warming the planet, ushering in an ice age. As humanity churns greenhouse gas emissions into Earth’s atmosphere, those in power should consider the fact that, just as the Great Oxidation event demonstrates, a single organism can trigger massive shifts simply by altering the flow of just a few elements.

Prehistoric plants dramatically altered Earth’s geology, triggering the creation of carbon-storing limestone.

Plants, particularly their root systems, were pivotal in reshaping Earth’s geology, soils, and atmosphere. Two billion years after the planet’s first ice age, plants “emerged from the water onto the continents,” colonizing the portion of Earth’s surface (under a third) above sea level. Land plants adapted to the lack of phosphorous in their new environment, burrowing their roots into the rock beneath them to secure access to this crucial element. By rooting into the bedrock, plants created soil and accessed phosphorus at unprecedented levels, enabling them to “grow as nothing had grown before, creating towering forests on once-unvegetated continents that then spanned from the equator to the South Pole.”

“It took a long time and some geologic happenstance for oxygen-producing photosynthesis to change the world. But once it did, Earth never went back. Life changed the planet forever.”

As the planet’s first land plants photosynthesized, they drew carbon and oxygen from the atmosphere at such high volumes that the blanket of CO2 warming the planet began to thin, ushering in another ice age. Plant root activity triggered organic decomposition in soil, releasing CO2 into soil water. This water became acidic, and as it traveled through water systems toward the ocean, it formed limestone (because the calcium in the oceans reacted with CO2). Today, the carbon-rich limestone, which has sequestered carbon for millennia, continues to help regulate the climate. Also, roughly 300 million years ago, tectonic plate movement gave rise to lowland swamps in sunny areas near Earth’s equator, trapping carbon from dead plant material in the waterlogged “ooze” beneath swamps, resulting in the creation of the coal we burn today.

Merging slow and fast carbon cycles by burning fossil fuels speeds up global warming at unprecedented rates.

Since the last ice age, the average temperature of Earth has risen only about 7°F — despite sounding like a small number, it portends significant change to come. Just 2°F of that increase has occurred in the past 50 years, and unless humanity shifts course by dramatically reducing carbon reliance, Earth’s temperature could rise another 7°F by the end of the 21st century. In other words, human activity would cause temperatures to rise as much in a single human lifespan as it has in the time between the end of the last ice age and the onset of the Industrial Revolution.

“Warming is causing ice melt in the Himalayas and threatening the water supply of almost a billion people. Almost all glaciers around the world are retreating at an ever-accelerating pace. Spring thaw is coming earlier, and fall frost later, in every place that regularly gets either.”

The Earth has both natural warming and cooling mechanisms, keeping ecosystems in balance. Before the Industrial Revolution, carbon only escaped the deeply buried rocks it was trapped in, warming the planet, when volcanoes erupted — this occurred at a fairly constant rate, and this form of carbon release occurred in what’s called a “slow carbon cycle.” When plants capture atmospheric carbon from the air, these carbon withdrawals are also part of this slow cycle. By contrast, when you exhale or an apple decomposes, carbon gets released into the atmosphere in a “fast carbon cycle.” Humans are the first species to merge fast and slow carbon cycles, via activities such as burning fossil fuels, and the consequences of this unprecedented behavior are uncertain, yet likely dramatic, given the rapid changes to Earth’s atmosphere.

Humanity needs to reduce reliance on carbon and nitrogen to prevent catastrophic global warming.

If humanity wants to avoid catastrophic levels of global warming, it needs to eliminate deforestation and fossil fuel emissions in the next two decades and start storing C02 underground using new technologies — doing so could limit the temperature rise to 3 or 4 degrees Fahrenheit. In such a scenario, Earth would look different — several species, for example, would go extinct, and some coastal cities would shrink or even disappear — but the planet would still sustain human life. In addition to addressing carbon emissions, reducing reliance on industrial nitrogen fixation is crucial. German scientist Fritz Haber made nitrogen more readily available by developing the Haber-Bosch process: By combining hydrogen and nitrogen, he produced ammonia (NH3), which became a key ingredient in synthetic fertilizers. Unfortunately, the nitrogen used for the hydrogen employed in the Haber-Bosch process is derived primarily from methane, a fossil fuel and greenhouse gas.

“For better and worse, we dominate the flows of nitrogen, the most mercurial element in Life’s Formula, as much as we do carbon. We reap the benefits and pay the consequences, just as the cyanobacteria did before us.”

Natural nitrogen-fixing has long been a part of farming: Before the mid-19th century, farmers would plant legumes specifically to add nitrogen back (removed after they harvested their crops), enabling the bacteria on the legumes to create nitrogen-rich soil. Producing food on a vast industrial level to feed everyone in the world currently requires farmers to use synthetic fertilizers, but environmentalists argue that new alternatives to nitrogen fertilizer are much needed, as the Haber-Bosch process contributes to global warming.

Phosphorous is needed to sustain life — and it’s in scarce supply.

If you’re like most people, you probably don’t give phosphorous much thought, but it’s vital when it comes to sustaining life. Your cells could not exist without phosphorous, as it “forms part of the backbone of DNA.” Unfortunately, phosphorous is scarce and occurs only in low concentrations in water and rocks. Unfortunately, regions with ancient soils, such as those on the island of Kauai in Hawaii and in the Amazon rainforest, are slowly losing supplies of phosphorous. For plants growing in “phosphorous-limited” areas — such as Kauai, where volcanic phosphorous is dwindling — growth can be a challenge. Currently, research shows that Kauai’s forests are barely hanging on, sustained only by a “trickle of continental dust, blown all the way from the Gobi Desert in Asia,” which brings phosphorus back to the soil.

“For something that’s irreplaceable for all life, phosphorus is hard to come by.”

Human intervention contributes significantly to phosphorous scarcity: In Kauai and the Amazon, practices such as deforestation and reliance on chemical fertilizers disrupt phosphorus cycling, throwing off an already delicate elemental balance, removing nutrients from the soil. Human intervention in ancient forests doesn’t benefit farmers or local economies in the long-term, as farmers can barely “eke out” a living once they’ve leached all the nutrients and phosphorus from the soil: They can’t grow crops without the use of chemical fertilizers, the use of which damages the soil and hinders phosphorus reuptake. When left alone, forests with ancient soils can actually reuse phosphorus, returning it to the soil by using their roots to find and recycle phosphorous from dropped leaves.

Irrigating dry regions can increase soil salinization and ultimately kill crops.

Humans use roughly “four trillion cubic meters of water per year.” It can be difficult to imagine such a big number, but try visualizing the entire United States submerged in half a meter of water, and you’ll be in the right ballpark. This water comes from two main sources: surface water, which is drained from rivers and lakes, and groundwater, which is filtered through rocks and soil. Many regions rely heavily on water irrigation, such as California’s Central Valley, which produces a quarter of the agricultural food consumed by people living in the United States. The region lacks sufficient rainfall — it gets only about a foot of rain annually — to grow enough crops, so must divert water from other areas, such as the Colorado River.

“Soil salinization is a real problem, and it will inevitably increase as irrigation of dry regions continues to expand.”

In arid regions, such as the valley in California, irrigation doesn’t necessarily create a healthy ecosystem, as adding water to plants doesn’t “flush the system out from the bottom” in the same way that plants growing in regions with abundant supplies of groundwater do: Instead, the plants draw up the water and expel it through their pores, or the water in the soil evaporates without journeying through the plants. This can result in salinization — the accumulation of salt in soil, which can make plant growth difficult and harm soil quality, causing problems long-term.

Humanity must radically rethink its approach to agriculture, reducing production of red meat.

If humanity wanted to make a game-changing effort to protect the delicate ratio of chemical elements necessary for life and ecosystem stability, people would rethink food production: Currently, a third of cropland worldwide is allocated to growing food for animals, which wastes far more resources — roughly 10 times the nitrogen, phosphorus, and water — than simply growing plants to feed humans directly would. When planning food production, people should aim to maximize energy availability, as opposed to choosing the most carbon-intensive food sources. Relying less on red meat as a food source is one of the biggest actions humanity can take to make its food system more sustainable.

Moving toward a green energy transition is also a vital necessity: If humanity fails to transition away from burning coal and fossil fuels, the planet will cease to sustain human society as you know it.

“It’s a bleak picture that has been painted many times. But it is not destiny.”

However, there is hope. Fortunately, unlike cyanobacteria, humanity has a key advantage: the ability to learn from its mistakes and act with foresight.

About the Author

Stephen Porder is the Associate Provost for Sustainability at Brown University, where he’s also a professor of ecology, evolution, organismal biology, and environment and society.