Ecosystem collapse is no longer in the realm of science fiction. It is upon us

The “collapse” of ecosystems has been a bedrock of science fiction from films such as Blade Runner and Disney’s Wall-E, to novels such as Margaret Atwood’s The Handmaid’s Tale and Cormac McCarthy’s The Road.
Predictions of an impending apocalypse are a feature of recorded human history, and far outdate modern culture. Popular conceptions of “collapse” can therefore make it difficult to discuss as a serious subject without appearing overly alarmist or histrionic. Nevertheless, the term is profoundly important in understanding humanity’s past, present and future.
The word “ecosystem” describes a complex network of interactions between living (biotic) organisms (plants, animals, fungi and so on) and nonliving (abiotic) elements (climate, water, rocks and soil). Although seemingly chaotic, ecosystems can be remarkably stable, the rainforests of the Amazon and southeast Asia, for instance, have been around for tens of millions of years. But they can also quickly flip into a new state; frozen ice age tundra has, in the past, developed into lush forests and wetlands over the space of hundreds or thousands of years, and vice versa.
The International Union for the Conservation of Nature (IUCN), which this year published new guidance for assessing the risk of collapse of ecosystems (something the organisation has been doing for species for many years), says that “an ecosystem is collapsed when it is virtually certain that its defining biotic or abiotic features are lost from all occurrences, and the characteristic native biota are no longer sustained”.
The document references the infamous case of the Aral Sea in central Asia. In 1960 the lake held 20 species of fish, more than 150 unique invertebrates, shoreline reed beds and populations of migratory birds. By 2005, due to the extraction of water for irrigating crops of cotton, only 28 species of fish or invertebrate remained, the lake had contracted to a fraction of its former size, salinity of the remaining water increased tenfold and the reed beds had “dried and disappeared”. The lake has entered a new stable state and, while it is not dead, it is a shadow of its former self.
Although the case of the Aral Sea has been well documented, the state of ecosystems more broadly is very poorly understood. While the IUCN has determined the status of 163,000 individual species, only 4,000 ecosystems have been assessed, although this number is increasing.
No ecosystem in Ireland has been formally assessed using the IUCN criteria, but by their definition, every natural ecosystem on land and sea is in a state of collapse. Whether it’s the reduction in extent of our native forests from a historic 80 per cent of land area to the current 1-2 per cent, or the near total removal of seabed habitats from bottom trawling, it is an indisputable fact that ecosystem collapse is evident no matter where you are in Ireland. Quite recently, the ecology of Lough Neagh in Northern Ireland has collapsed into a new steady state as a result of pollution, invasive species and unsustainable excavation of the lake bed.
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This has been a blind spot of conservationists, who have fought to save individual species from extinction. The approach has overlooked the fact that although some species are not at risk of extinction, such as herring or oak trees, their abundance today is so diminished that they no longer play the role they once did in healthy ecosystems. This matters because the world turns on the working of healthy ecosystems, which drive essential cycles of carbon, oxygen, water and soil fertility. As ecosystems collapse, so these cycles grind to a halt.
This, in turn, matters to humanity as our civilisation has developed during a benign, and stable, period of history, where the patterns of climate, rainfall and agricultural production have been relatively reliable. Intact ecosystems are now under pressure everywhere, with some critically important ones, such as Amazon rainforest, coral reefs and the polar ice caps, teetering on the edge.
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The integrity of these natural ecosystems has been identified as among critical thresholds, or tipping points, that could shift planetary conditions out of its comfort zone and into a new and very different state. Collapse, in other words.
Johan Rockström of the Stockholm Resilience Centre and the University of Potsdam helped to define the “planetary boundaries” that have been the envelope of modern humanity. In July he provided an update on the state of tipping points in a Ted talk.
Ice caps, rainforests and coral reefs are all showing signs of flickering, like the blinking of a light bulb before it blows. This includes the Atlantic Meridional Overturning Circulation, or AMOC, which, it if shut down, would rapidly send Ireland back to Arctic-like conditions. “Abrupt changes are occurring in a way that is way beyond the realistic expectations in science,” he said.
This, Rockström emphasised, was all being driven by burning of fossil fuels and degradation of ecosystems, such as forests and oceans, that have, up to now, provided buffering due to their ability to absorb carbon. This buffering capacity is now rapidly diminishing, while carbon-dioxide concentrations are now already at levels not experienced in three million years. He advised his audience to “buckle up”.
David Korowitz trained as a physicist but now describes himself as a human system ecologist who has worked for Irish and international NGOs. He described his work as analysing systemic risk, including risk of collapse of institutions. He studies the interrelationships between multiple complex systems, such as finance, food, energy and sanitation, as well as environmental, which he believes has reached a critical level of vulnerability due to the extent of global interactions.
These have been fairly stable up to now, which helps to explain the ease with which people tend to ignore the current predicament. “Why would you worry about food security when you can go to the supermarket and there’s a cornucopia of choice?” However, such complexity leads to vulnerability. Very few people know how to produce food, and even those who do tend to produce only one or two types. “There isn’t a single person who knows how to build a computer,” says Korowitz.
In such systems, “the absence of just one thing can have a catastrophic impact”. He describes these systems as “kind of like a living organism. We didn’t design them, they’re self-organised. We can shape them, but we don’t control them. We don’t even fully understand them.”
In the past 200 years these systems have only accelerated in speed and complexity while modern human society has evolved within this multilayered web of human-made and natural dynamics that is, by definition, out of all control.
Along with vulnerability, Korowitz says there are more and more emerging stresses and shocks that threaten the narrow guardrails in which humanity has developed: pandemics, social polarisation, extreme climate events and biodiversity loss, for instance. Collapse, in his view is “almost inevitable” and if/when it happens it can be “incredibly fast”. This, he says, will be a shutdown in goods and services, a slowing, or halting of the metabolism of our society.
Nevertheless, despair is not the appropriate response. The IUCN points out that “ecosystem collapse may in theory be reversible – given a long-time frame, or via the reintroduction of characteristic biota and/or the restoration of ecosystem function”. Even the former ecology of the Aral Sea, it notes, could be restored somewhat.
In his Ted talk, Rockström is keen to stress there is still a window where a global collapse can be avoided, through rapid decarbonisation and restoration of ecosystems.
Korowitz recommends not talking about collapse directly. “We don’t want to say ‘we’re screwed’ but neither can we say ‘don’t worry your head about it’”. What he suggests is training at a very local level in disaster preparedness – say for a shutdown of the electrical grid for a prolonged period, or an extreme climate event. What we need is a “whole-of-society preparedness effort” in addition to governments making behind-the-scenes plans.
There are many examples of past human societies undergoing collapse as they failed to read the warning signs. Modern humans could follow this path, or we could take action now.