“Philip Larkin famously proposed that what will survive of us is love. Wrong. What will survive of us is plastic, swine bones, and lead-207, the stable isotope at the end of the uranium-235 decay chain.”
Robert Macfarlane, Underland

Swabia, Jurassic – 155 million years ago

This land does not exist yet.
In its place lies a shallow, tropical sea. Europe is broken up into islands, and Swabia sits closer to the equator than today.

Ammonites drift above the seabed, their air-filled spiral shells holding them balanced in the water. Above them, a Plesioteuthis is lurking close to the surface, waiting for an unwary Rhamphorhynchus to swoop too low over the lagoon. A few meters away, a log drifts by. It is trailing enormous stalks behind it that scare the Plesioteuthis off.

The owners of the 20-meter-long stalks are sea lilies (Seirocrinus). They, together with molluscs, shellfish, and echinoderms, colonize the driftwood. They themselves build biomass for small fish to feed on. Together, they build unique raft communities that can exist for decades before the wood falls apart, allowing Seirocrinus to grow to its enormous size. This longevity is only possible because wood-boring predators like shipworms haven’t evolved yet. They will only appear later in the Cretaceous and end these ecosystems forever.

Driftwood communities, along with Plesioteuthis and Rhamphorhynchus, are gone today, and they will never return. In fact, well over 99 percent of life that existed on our planet went extinct, and that is perfectly fine.

When we read about these bygone ecosystems in the fossil record, we are not reading tragedies. We inevitably suffer from something called the Shifting Baseline Syndrome (SBS). We tend to create a still image of the world sometime during our childhood. This freeze-frame becomes our status quo. Any change becomes something the world shouldn’t be. But this is an illusion. Ecosystems are events, not conditions. Deep time has no reference point. There is no baseline to return to—only previous versions of Earth we can no longer reach.

Extinction is an inevitable part of this. Every organism exists within a range of conditions it can tolerate. That is its fundamental niche. Temperature, oxygen, and food availability all define the outer limits of that niche. No species, however, occupies its full potential niche. Competition with other organisms restricts the actual occupation of that potential niche. This smaller inhabitable range is the realized niche. If environmental conditions remain within these bounds, a species can persist. When conditions shift beyond them—through habitat loss or the introduction of a new predator, as in the case of the Jurassic driftwood communities—the realized niche collapses. What follows is extinction, and it happened time and time again.

In the Jurassic, corals were not the domineering reef builders. With their high resistance to high temperatures and acidification levels, glass sponges, or hexactinellids, were the predominant species. Their syncytial structure let electrical signals travel rapidly, coordinating filtration across the entire organism despite the absence of a nervous system. These glass sponge reefs did not depend on sunlight; they filtered bacteria and organic particles directly from seawater, pumping tens of thousands of litres each day through their bodies. Sediments and mud, however, clog their filtration systems. Therefore, sponge reefs existed in deeper waters, far away from the mouths of rivers. When ocean circulation shifted and silicia concentrartions in the ocean were reduced, sponges could no longer sustain large reef structures. Their realized niche shrank and ultimately collapsed. Glass sponge reefs disappeared, never to return in the same way. 

Today, corals are the dominant reef builders in our Earth’s oceans, but their realized niche is shrinking. Corals live close to their upper thermal limits, and even modest increases in ocean temperature disrupt their symbiosis with photosynthetic algae, leading to bleaching and reduced survival. At the same time, the absorption of carbon dioxide by seawater lowers pH and reduces the availability of carbonate ions, increasing the energetic cost of reef building and slowing skeletal growth.

The potential extinction of corals is a tragedy for us. But why is that? Corals will go extinct at some point. Why should we care? Sponge reefs went extinct, and so will coral reefs.

There is only one factor that differentiates the vanishing of sponge reefs from the face of the Earth and the potential loss of coral reefs.
This factor is us.

For the first time, a single species can knowingly create effects that endure far beyond its own lifetime. Humans create effects that outlast civilizations. We are designing legacies we cannot witness. Deep time is no longer just happening. We are actively shaping it.

Our ability to foresee our impact on deep time turns natural processes into ethical terrain.
A terrain that is inherently complicated for us to grasp. If Earth had existed for only 24 hours, a human life would last 1 millisecond. One blink of an eye takes 300 times longer than that. Modern humans would have been around for only 0.1 seconds.

Yet, in that very short span of time, we have altered Earth so much that we are already discussing whether we “deserve” our own geological timescale.

The Anthropocene is a proposed epoch in the geological timescale. For the validation of the Anthropocene as an epoch, it is important to consider when human impact on Earth became undeniable, but more importantly, to seek material evidence like lithology, chemical signatures, or physical objects. The most abundant evidence is human trace fossils in the form of microplastics, which are found in abundance in marine sediments worldwide.

Post-industrialization, human impact on Earth has not only been massive but incredibly fast. We are altering the planet so fast that evolution simply cannot keep up. The results are massive disruptions in ecosystems we can already feel and see.

Knowing about our doings further creates an unprecedented asymmetry of knowledge. We leave markers intended to warn distant descendants of buried dangers like radioactive isotopes decaying over millennia, anticipating a future we will never witness. But at the same time, we nonchalantly disregard warnings already visible at the surface: declining populations, collapsing habitats, disrupted weather patterns, and far-accelerated species loss.

For most of Earth’s history, extinction just happened. Species disappeared because of conditional or behavioural changes. We, however, possess the ability to model futures, trace causality chains, and anticipate consequences of behaviour. Extinction is not an unforeseen side effect; it is an outcome that can be described, quantified, and projected.

Extinction without intent is geology.
Extinction with foresight is something else.

We are a species able to anticipate our demise, yet we refuse to act on it. Knowledge is no guarantee of intervention. It only changes the context in which loss occurs.

The fossil record is often mistaken for a complete history of our planet. But that is simply not true. It is a collection of chance. It shows only a fraction of what lived. Entire ecosystems vanished without leaving a single trace. They are simply overwritten by the next. The record now forming is different. Signatures accumulating in the strata are synthetic materials and altered chemical ratios. Plastics endure because they were designed to. Chemical signatures persist because we make them. Species disappear because drivers of loss are implemented globally and coordinated. Our fossil record is not an accident, but a message inscribed into deep time.

We find similar messages in the fossil record. Extinction is happening all the time, even in crisis-free times. This is called background extinction. When extinction rates rise far above background levels, we speak of mass extinctions. Events trigger change too fast for life to replace or adapt. So far, this has happened five times in Earth’s history.

The most severe extinction event was the end-Permian extinction 252 million years ago, which wiped out 96 percent of all marine species. Volcanic activity from the Siberian Traps caused extreme warming, ocean acidification, and oxygen loss, and collapsed most ecosystems. The most recent mass extinction, at the end of the Cretaceous 66 million years ago, removed about 75 percent of species, including all non-avian dinosaurs, when an asteroid impact and extensive volcanic eruptions forming the Deccan Traps combined. These effects destabilized climate, altered ocean chemistry, and ultimately collapsed global food webs.

Today, no comparable large igneous province like the Siberian or Deccan Traps is active. Yet extinction rates are elevated far above background levels. Our impact on the planet is so devastating that, if current extinction rates continue, they could generate an extinction biohorizon comparable in scale to the five major mass extinctions, forming within only a few centuries.

When we finally succeed in killing our planet, the corals won’t have died out because steady changes slowly eroded their realized niche, as happened to the vast sponge reefs of the Jurassic. They also won’t have died out due to cataclysmic volcanic eruptions that changed the ocean’s constitution too fast for them to adapt. They will have died out because we made them.

What will survive of us is surely not love, but negligence.

An Article by Jona-Tristan Köhring