Land Change, Failures of Omission, and the Renaturing of Climate

Land Change, Failures of Omission, and the Renaturing of Climate

by | Dec 9, 2022 | ANALYSIS, Biodiversity & Habitat Destruction

“All ethics so far evolved rest upon a single premise: that the individual is a member of a community of interdependent parts. The land ethic simply enlarges the boundaries of the community to include soils, waters, plants and animals, or collectively the land.” – Aldo Leopold, The Land Ethic, A Sand County Almanac.

By Rob Lewis, originally published by Resilience.org

Land change is a scientific term you’re not likely to hear in mainstream climate conversation, which is a shame, because what it refers to, the climatic effects of human damage to living landscapes, is a big part of the climate crisis. I talk in greater detail about land change and how it got left out of the climate narrative in an earlier Resilience piece, called Putting the Land Back in Climate. Here, I want to consider the effects of this omission, not only in the practical terms of climate policy, but in terms less definitive. What does it mean to our treatment of the land that it’s gotten to be left out of our picture of climate? Or another way of putting it: how does not knowing that our local landscapes hydrate, cool and stabilize our climates, affect our relationship with those landscapes or lack thereof?

But first I want to be clear that nothing here questions or counters the danger of carbon emissions, the greenhouse effect, or subsequent global warming. Land change should be seen as being in addition to these things, or more to the point, intimately entwined with them. The climate, when fully comprehended, emerges as a constellation of actors and effects, physical and biological, with an unimaginable complexity of feedbacks and signals. To reduce it all to quantities of carbon, and speak only of that, is to miss the thing itself.

So let’s quickly review what land change is and how it got left out the climate picture.

One way to think of land change is as original climate change. We began changing climates as soon as we started draining marshes and plowing soil, as observed in the time-worn adage: desert follows the plow, and seen now in deserts like those of the Middle East, which were once lush with marshlands and cypress-draped hills. The reason has to do with water cycles, which are largely invisible to us. We don’t see the roots underground, interlinking with extravagant webbings of soil fungi, soaking up spongelike massive quantities of water, around 600 liters per day for the average tree. Nor do we see the water evaporating from microscopic pores under the surfaces of leaves and needles, which like all evaporation, is profoundly cooling. And we don’t see the columns of vapor rising from trees and fields, feeding the clouds overhead to rain somewhere else and continue the cycle. Lastly, we don’t see the soil absorbing and holding that moisture, banking the landscape against drought and flood. Life not only sequesters carbon, it sequesters water as well. The two, it turns out, go hand in hand.

Scientists refer to this with the term evapotranspiration and know it to be fundamental to the hydration, cooling and moderation of local and regional climates. It follows then, that when we damage, or “change” land it dries out, heats up, and becomes prone to hydrological extremes like drought, floods and heatwaves. Sound familiar?

When coal and oil was discovered, a new cause of climate change entered the picture: emissions of greenhouse gasses. And early climate science treated it that way, as an additional cause, not the cause. Mediterranean-climate expert Millan Millan remembers that time, referring to it as a “two-legged” climate understanding—one leg for land change and hydrological effects and a second leg for carbon emissions and the greenhouse effect. So how then did we arrive at an official narrative which describes only carbon emissions as the cause of climate change? What happened to the land leg?

A clue can be found in the titles of the IPCC’s periodical Assessment Reports, such as the most recent assessment Global Climate Change 2021: The Physical Science Basis. What is meant by those last four words? The easiest answer is to think of the physical science basis is as the mathematic, or quantitative basis, the basis necessary for the computer modelling of climate. When CO2 emissions emerged as a climate threat, science immediately turned to computer modelling to ascertain and predict the effects. Carbon emissions, well dispersed in the atmosphere, proved highly amenable to such modeling, while the biological/hydrological processes of land change were the opposite. Though we can feel the effects of land-change, and are surrounded by it in the form of wastelands and vanished species, it is almost impossible to render in quantitative terms. The processes are too detailed, complex, varied and changing.

A good many scientists are currently working to resolve the matter, quantifying land change effects and bringing them into global computer models, and we can expect the next round of IPCC assessments to include some of this work. But that’s still five to six years off, and by then trillions will have been spent on industrial infrastructure causing how much land change?

This must be the first and most tragic effect of leaving land change and water cycles out of the analysis. Nature disappears, reduced to quantities of carbon, buried under tech jargon, sacrificed all over again for a new era of human device and progress. To the plow, the ax and cattle drive, we now add the solar farm, transmission corridor and a new generation of mines.

Environmentalism has suffered mightily from this formulation, and now confronts a kind of ecological Sophie’s Choice: either sacrifice the land or sacrifice the climate. It can be that stark. Consider the US state of Virginia, who’s recently passed climate legislation is resulting in thousands of acres of forest being cut for solar farms and transmission corridors, much of it to support data centers for tech corporations like Google and Microsoft. Meanwhile, those citizens who elect to protect their forests rather than sacrifice them for energy generation are labeled NIMBYs.

But there’s more. With this big industrial push comes a parallel push for what is being called “permit reform.” The Inflation Reduction Act, recently passed in the US, contains 1.2 billion dollars to staff up permitting agencies in an attempt to rush this infrastructure. And I noticed, when Senator Joe Manchin tried to attach a “permit reform” bill to the IRA, the official environmental opposition was carefully directed at only the permitting reform around fossil fuels. Presumably, they are for it when it comes to industrial infrastructure deemed “green” or “clean.” Thus, another dichotomy: big green working to take away permitting power from little green, the locals defending their own land bases. Ask yourself how long you think such contradictions can last.

There’s a personal dimension here as well. I know for myself, once I began learning about the biological, water-based aspects of climate, my view of climate and the natural world transformed. Muir’s oft-quoted observation, “when we try to pick out anything by itself, we find it hitched to everything else in the universe” suddenly came alive. I discovered, over and over, that when I grabbed the thread called “climate” it was hitched to everything on Earth, part of something very much alive and capable of recovery. And with that my doom, not my worry and concern and grief, but that powerless sense of doom vanished. I stood on different ground, having come to know its power.

Now I see my surroundings, my climate-shed if you will, not as climatically helpless against rising CO2 emissions, but the very basis for climate healing and recovery. This is what happens when you bring the living land back into the climate equation, it comes alive. The land turns ally, and a new clarity emerges, with a very different set of priorities.

First, protect all remaining wild and semi-wild places. They are the last living links to the once cool, wet Holocene climate, which we can still save. Understand that where land is at its healthiest, so it’s climate function.

Second, restore the lands we’ve already damaged. Here is where hope literally grows. For buried within the sad fact that half of Earth’s land has been converted to human use, is the stunning comprehension of just how much land is available and waiting for restoration, bringing new carbon sequestration and water cycling to the climate system at game-changing scale.

Third, stop “changing” land. Housing developments, logging, road building, solar farming, all continue with no public awareness of the climate damage being done. Integrate land change into the environmental review process.

Fourth, slow down, cool down—the only thing that ever has reduced emissions. The land is telling it needs rest and recovery, not to be subjected to a new industrial revolution.

Do we really need decades of climate modelling to figure these things out? Might there be other ways of approaching this crisis?

We are not alone in this. For the land, though degraded, still retains its potential for regeneration. Given a little protection, ecosystems recover. Even the poorest soils contain ancient seeds of bygone life, awaiting only water. And in the field, the land’s enthusiasm for reemergence continually exceeds the expectations of those working to restore it. It turns out that regeneration, and the passion for regeneration, is in the very grain and fiber of all that surrounds us.

Those seeds are in us too. That’s the invitation. But only the land, and the processes of life, can bring the water.

Photo by American Public Power Association on Unsplash

Top Scientists: We Face “A Ghastly Future”

Top Scientists: We Face “A Ghastly Future”

by | Sep 23, 2022 | Biodiversity & Habitat Destruction, NEWS

Editor’s note: According to the scientists who wrote the following paper, “future environmental conditions will be far more dangerous than currently believed. The scale of the threats to the biosphere and all its lifeforms—including humanity—is in fact so great that it is difficult to grasp for even well-informed experts.”

We agree, and have been working to both inform people about these issues and to resist the destruction of the planet since our organization formed over a decade ago. “Any else [other than telling the truth about our ecological crisis] is misleading at best,” the scientists write, “or negligent and potentially lethal for the human enterprise [and, we must add, much of life on this planet] at worst.”

Modern civilization is a society of the spectacle in which media corporations focus more on who won the football game or how the queen is buried than about the breakdown of planetary ecology. This scientific report is essential reading and should be a headline news story worldwide. However, this information is inherently subversive, and therefore is either ignored or framed in such a way as to support the goals of the wealthy.

For years, our co-founder Derrick Jensen has asked his audiences, “Do you think this culture will undergo a voluntary transformation to a sane and sustainable way of life?” No one ever says yes. This is why Deep Green Resistance exists.

Deep Green Resistance starts where the environmental movement leaves off: industrial civilization is incompatible with life. Technology can’t fix it, and shopping—no matter how green—won’t stop it. To save this planet, we need a serious resistance movement that can bring down the industrial economy. Deep Green Resistance is a plan of action for anyone determined to fight for this planet—and win.

Underestimating the Challenges of Avoiding a Ghastly Future

PERSPECTIVE article Frontiers in Conservation Science, 13 January 2021 Section Global Biodiversity Threats https://doi.org/10.3389/fcosc.2020.615419

By Bradshaw, Ehrlich, Beattie, Ceballos, Crist, Diamond, Dirzo, Ehrlich, Harte, Harte, Pyke, Raven, Ripple, Saltré, Turnbull, Wackernagel, and Blumstein

We report three major and confronting environmental issues that have received little attention and require urgent action. First, we review the evidence that future environmental conditions will be far more dangerous than currently believed. The scale of the threats to the biosphere and all its lifeforms—including humanity—is in fact so great that it is difficult to grasp for even well-informed experts. Second, we ask what political or economic system, or leadership, is prepared to handle the predicted disasters, or even capable of such action. Third, this dire situation places an extraordinary responsibility on scientists to speak out candidly and accurately when engaging with government, business, and the public. We especially draw attention to the lack of appreciation of the enormous challenges to creating a sustainable future. The added stresses to human health, wealth, and well-being will perversely diminish our political capacity to mitigate the erosion of ecosystem services on which society depends. The science underlying these issues is strong, but awareness is weak. Without fully appreciating and broadcasting the scale of the problems and the enormity of the solutions required, society will fail to achieve even modest sustainability goals.

Introduction

Humanity is causing a rapid loss of biodiversity and, with it, Earth’s ability to support complex life. But the mainstream is having difficulty grasping the magnitude of this loss, despite the steady erosion of the fabric of human civilization (Ceballos et al., 2015; IPBES, 2019; Convention on Biological Diversity, 2020; WWF, 2020). While suggested solutions abound (Díaz et al., 2019), the current scale of their implementation does not match the relentless progression of biodiversity loss (Cumming et al., 2006) and other existential threats tied to the continuous expansion of the human enterprise (Rees, 2020). Time delays between ecological deterioration and socio-economic penalties, as with climate disruption for example (IPCC, 2014), impede recognition of the magnitude of the challenge and timely counteraction needed. In addition, disciplinary specialization and insularity encourage unfamiliarity with the complex adaptive systems (Levin, 1999) in which problems and their potential solutions are embedded (Selby, 2006; Brand and Karvonen, 2007). Widespread ignorance of human behavior (Van Bavel et al., 2020) and the incremental nature of socio-political processes that plan and implement solutions further delay effective action (Shanley and López, 2009; King, 2016).

We summarize the state of the natural world in stark form here to help clarify the gravity of the human predicament. We also outline likely future trends in biodiversity decline (Díaz et al., 2019), climate disruption (Ripple et al., 2020), and human consumption and population growth to demonstrate the near certainty that these problems will worsen over the coming decades, with negative impacts for centuries to come. Finally, we discuss the ineffectiveness of current and planned actions that are attempting to address the ominous erosion of Earth’s life-support system. Ours is not a call to surrender—we aim to provide leaders with a realistic “cold shower” of the state of the planet that is essential for planning to avoid a ghastly future.

Biodiversity Loss

Major changes in the biosphere are directly linked to the growth of human systems (summarized in Figure 1). While the rapid loss of species and populations differs regionally in intensity (Ceballos et al., 2015, 2017, 2020; Díaz et al., 2019), and most species have not been adequately assessed for extinction risk (Webb and Mindel, 2015), certain global trends are obvious. Since the start of agriculture around 11,000 years ago, the biomass of terrestrial vegetation has been halved (Erb et al., 2018), with a corresponding loss of >20% of its original biodiversity (Díaz et al., 2019), together denoting that >70% of the Earth’s land surface has been altered by Homo sapiens (IPBES, 2019). There have been >700 documented vertebrate (Díaz et al., 2019) and ~600 plant (Humphreys et al., 2019) species extinctions over the past 500 years, with many more species clearly having gone extinct unrecorded (Tedesco et al., 2014). Population sizes of vertebrate species that have been monitored across years have declined by an average of 68% over the last five decades (WWF, 2020), with certain population clusters in extreme decline (Leung et al., 2020), thus presaging the imminent extinction of their species (Ceballos et al., 2020). Overall, perhaps 1 million species are threatened with extinction in the near future out of an estimated 7–10 million eukaryotic species on the planet (Mora et al., 2011), with around 40% of plants alone considered endangered (Antonelli et al., 2020). Today, the global biomass of wild mammals is <25% of that estimated for the Late Pleistocene (Bar-On et al., 2018), while insects are also disappearing rapidly in many regions (Wagner, 2020; reviews in van Klink et al., 2020).

FIGURE 1

www.frontiersin.org

Figure 1. Summary of major environmental-change categories expressed as a percentage change relative to the baseline given in the text. Red indicates the percentage of the category that is damaged, lost, or otherwise affected, whereas blue indicates the percentage that is intact, remaining, or otherwise unaffected. Superscript numbers indicate the following references: 1IPBES, 2019; 2Halpern et al., 2015; 3Krumhansl et al., 2016; 4Waycott et al., 2009; 5Díaz et al., 2019; 6Christensen et al., 2014; 7Frieler et al., 2013; 8Erb et al., 2018; 9Davidson, 2014; 10Grill et al., 2019; 11WWF, 2020; 12Bar-On et al., 2018; 13Antonelli et al., 2020; 14Mora et al., 2011.

Freshwater and marine environments have also been severely damaged. Today there is <15% of the original wetland area globally than was present 300 years ago (Davidson, 2014), and >75% of rivers >1,000 km long no longer flow freely along their entire course (Grill et al., 2019). More than two-thirds of the oceans have been compromised to some extent by human activities (Halpern et al., 2015), live coral cover on reefs has halved in <200 years (Frieler et al., 2013), seagrass extent has been decreasing by 10% per decade over the last century (Waycott et al., 2009; Díaz et al., 2019), kelp forests have declined by ~40% (Krumhansl et al., 2016), and the biomass of large predatory fishes is now <33% of what it was last century (Christensen et al., 2014).

With such a rapid, catastrophic loss of biodiversity, the ecosystem services it provides have also declined. These include inter alia reduced carbon sequestration (Heath et al., 2005; Lal, 2008), reduced pollination (Potts et al., 2016), soil degradation (Lal, 2015), poorer water and air quality (Smith et al., 2013), more frequent and intense flooding (Bradshaw et al., 2007; Hinkel et al., 2014) and fires (Boer et al., 2020; Bowman et al., 2020), and compromised human health (Díaz et al., 2006; Bradshaw et al., 2019). As telling indicators of how much biomass humanity has transferred from natural ecosystems to our own use, of the estimated 0.17 Gt of living biomass of terrestrial vertebrates on Earth today, most is represented by livestock (59%) and human beings (36%)—only ~5% of this total biomass is made up by wild mammals, birds, reptiles, and amphibians (Bar-On et al., 2018). As of 2020, the overall material output of human endeavor exceeds the sum of all living biomass on Earth (Elhacham et al., 2020).

Sixth Mass Extinction

A mass extinction is defined as a loss of ~75% of all species on the planet over a geologically short interval—generally anything <3 million years (Jablonski et al., 1994; Barnosky et al., 2011). At least five major extinction events have occurred since the Cambrian (Sodhi et al., 2009), the most recent of them 66 million years ago at the close of the Cretaceous period. The background rate of extinction since then has been 0.1 extinctions million species−1 year−1 (Ceballos et al., 2015), while estimates of today’s extinction rate are orders of magnitude greater (Lamkin and Miller, 2016). Recorded vertebrate extinctions since the 16th century—the mere tip of the true extinction iceberg—give a rate of extinction of 1.3 species year−1, which is conservatively >15 times the background rate (Ceballos et al., 2015). The IUCN estimates that some 20% of all species are in danger of extinction over the next few decades, which greatly exceeds the background rate. That we are already on the path of a sixth major extinction is now scientifically undeniable (Barnosky et al., 2011; Ceballos et al., 2015, 2017).

Ecological Overshoot: Population Size and Overconsumption

The global human population has approximately doubled since 1970, reaching nearly 7.8 billion people today (prb.org). While some countries have stopped growing and even declined in size, world average fertility continues to be above replacement (2.3 children woman−1), with an average of 4.8 children woman−1 in Sub-Saharan Africa and fertilities >4 children woman−1 in many other countries (e.g., Afghanistan, Yemen, Timor-Leste). The 1.1 billion people today in Sub-Saharan Africa—a region expected to experience particularly harsh repercussions from climate change (Serdeczny et al., 2017)—is projected to double over the next 30 years. By 2050, the world population will likely grow to ~9.9 billion (prb.org), with growth projected by many to continue until well into the next century (Bradshaw and Brook, 2014; Gerland et al., 2014), although more recent estimates predict a peak toward the end of this century (Vollset et al., 2020).

Large population size and continued growth are implicated in many societal problems. The impact of population growth, combined with an imperfect distribution of resources, leads to massive food insecurity. By some estimates, 700–800 million people are starving and 1–2 billion are micronutrient-malnourished and unable to function fully, with prospects of many more food problems in the near future (Ehrlich and Harte, 2015a,b). Large populations and their continued growth are also drivers of soil degradation and biodiversity loss (Pimm et al., 2014). More people means that more synthetic compounds and dangerous throw-away plastics (Vethaak and Leslie, 2016) are manufactured, many of which add to the growing toxification of the Earth (Cribb, 2014). It also increases chances of pandemics (Daily and Ehrlich, 1996b) that fuel ever-more desperate hunts for scarce resources (Klare, 2012). Population growth is also a factor in many social ills, from crowding and joblessness, to deteriorating infrastructure and bad governance (Harte, 2007). There is mounting evidence that when populations are large and growing fast, they can be the sparks for both internal and international conflicts that lead to war (Klare, 2001; Toon et al., 2007). The multiple, interacting causes of civil war in particular are varied, including poverty, inequality, weak institutions, political grievance, ethnic divisions, and environmental stressors such as drought, deforestation, and land degradation (Homer-Dixon, 1991, 1999; Collier and Hoeer, 1998; Hauge and llingsen, 1998; Fearon and Laitin, 2003; Brückner, 2010; Acemoglu et al., 2017). Population growth itself can even increase the probability of military involvement in conflicts (Tir and Diehl, 1998). Countries with higher population growth rates experienced more social conflict since the Second World War (Acemoglu et al., 2017). In that study, an approximate doubling of a country’s population caused about four additional years of full-blown civil war or low-intensity conflict in the 1980s relative to the 1940–1950s, even after controlling for a country’s income-level, independence, and age structure.

Simultaneous with population growth, humanity’s consumption as a fraction of Earth’s regenerative capacity has grown from ~ 73% in 1960 to 170% in 2016 (Lin et al., 2018), with substantially greater per-person consumption in countries with highest income. With COVID-19, this overshoot dropped to 56% above Earth’s regenerative capacity, which means that between January and August 2020, humanity consumed as much as Earth can renew in the entire year (overshootday.org). While inequality among people and countries remains staggering, the global middle class has grown rapidly and exceeded half the human population by 2018 (Kharas and Hamel, 2018). Over 70% of all people currently live in countries that run a biocapacity deficit while also having less than world-average income, excluding them from compensating their biocapacity deficit through purchases (Wackernagel et al., 2019) and eroding future resilience via reduced food security (Ehrlich and Harte, 2015b). The consumption rates of high-income countries continue to be substantially higher than low-income countries, with many of the latter even experiencing declines in per-capita footprint (Dasgupta and Ehrlich, 2013; Wackernagel et al., 2019).

This massive ecological overshoot is largely enabled by the increasing use of fossil fuels. These convenient fuels have allowed us to decouple human demand from biological regeneration: 85% of commercial energy, 65% of fibers, and most plastics are now produced from fossil fuels. Also, food production depends on fossil-fuel input, with every unit of food energy produced requiring a multiple in fossil-fuel energy (e.g., 3 × for high-consuming countries like Canada, Australia, USA, and China; overshootday.org). This, coupled with increasing consumption of carbon-intensive meat (Ripple et al., 2014) congruent with the rising middle class, has exploded the global carbon footprint of agriculture. While climate change demands a full exit from fossil-fuel use well before 2050, pressures on the biosphere are likely to mount prior to decarbonization as humanity brings energy alternatives online. Consumption and biodiversity challenges will also be amplified by the enormous physical inertia of all large “stocks” that shape current trends: built infrastructure, energy systems, and human populations.

It is therefore also inevitable that aggregate consumption will increase at least into the near future, especially as affluence and population continue to grow in tandem (Wiedmann et al., 2020). Even if major catastrophes occur during this interval, they would unlikely affect the population trajectory until well into the 22nd Century (Bradshaw and Brook, 2014). Although population-connected climate change (Wynes and Nicholas, 2017) will worsen human mortality (Mora et al., 2017; Parks et al., 2020), morbidity (Patz et al., 2005; Díaz et al., 2006; Peng et al., 2011), development (Barreca and Schaller, 2020), cognition (Jacobson et al., 2019), agricultural yields (Verdin et al., 2005; Schmidhuber and Tubiello, 2007; Brown and Funk, 2008; Gaupp et al., 2020), and conflicts (Boas, 2015), there is no way—ethically or otherwise (barring extreme and unprecedented increases in human mortality)—to avoid rising human numbers and the accompanying overconsumption. That said, instituting human-rights policies to lower fertility and reining in consumption patterns could diminish the impacts of these phenomena (Rees, 2020).

Failed International Goals and Prospects for the Future

Stopping biodiversity loss is nowhere close to the top of any country’s priorities, trailing far behind other concerns such as employment, healthcare, economic growth, or currency stability. It is therefore no surprise that none of the Aichi Biodiversity Targets for 2020 set at the Convention on Biological Diversity’s (CBD.int) 2010 conference was met (Secretariat of the Convention on Biological Diversity, 2020). Even had they been met, they would have still fallen short of realizing any substantive reductions in extinction rate. More broadly, most of the nature-related United Nations Sustainable Development Goals (SDGs) (e.g., SDGs 6, 13–15) are also on track for failure (Wackernagel et al., 2017; Díaz et al., 2019; Messerli et al., 2019), largely because most SDGs have not adequately incorporated their interdependencies with other socio-economic factors (Bradshaw and Di Minin, 2019; Bradshaw et al., 2019; Messerli et al., 2019). Therefore, the apparent paradox of high and rising average standard of living despite a mounting environmental toll has come at a great cost to the stability of humanity’s medium- and long-term life-support system. In other words, humanity is running an ecological Ponzi scheme in which society robs nature and future generations to pay for boosting incomes in the short term (Ehrlich et al., 2012). Even the World Economic Forum, which is captive of dangerous greenwashing propaganda (Bakan, 2020), now recognizes biodiversity loss as one of the top threats to the global economy (World Economic Forum, 2020).

The emergence of a long-predicted pandemic (Daily and Ehrlich, 1996a), likely related to biodiversity loss, poignantly exemplifies how that imbalance is degrading both human health and wealth (Austin, 2020; Dobson et al., 2020; Roe et al., 2020). With three-quarters of new infectious diseases resulting from human-animal interactions, environmental degradation via climate change, deforestation, intensive farming, bushmeat hunting, and an exploding wildlife trade mean that the opportunities for pathogen-transferring interactions are high (Austin, 2020; Daszak et al., 2020). That much of this degradation is occurring in Biodiversity Hotspots where pathogen diversity is also highest (Keesing et al., 2010), but where institutional capacity is weakest, further increases the risk of pathogen release and spread (Austin, 2020; Schmeller et al., 2020).

Climate Disruption

The dangerous effects of climate change are much more evident to people than those of biodiversity loss (Legagneux et al., 2018), but society is still finding it difficult to deal with them effectively. Civilization has already exceeded a global warming of ~ 1.0°C above pre-industrial conditions, and is on track to cause at least a 1.5°C warming between 2030 and 2052 (IPCC, 2018). In fact, today’s greenhouse-gas concentration is >500 ppm CO2-e (Butler and Montzka, 2020), while according to the IPCC, 450 ppm CO2-e would give Earth a mere 66% chance of not exceeding a 2°C warming (IPCC, 2014). Greenhouse-gas concentration will continue to increase (via positive feedbacks such as melting permafrost and the release of stored methane) (Burke et al., 2018), resulting in further delay of temperature-reducing responses even if humanity stops using fossil fuels entirely well before 2030 (Steffen et al., 2018).

Human alteration of the climate has become globally detectable in any single day’s weather (Sippel et al., 2020). In fact, the world’s climate has matched or exceeded previous predictions (Brysse et al., 2013), possibly because of the IPCC’s reliance on averages from several models (Herger et al., 2018) and the language of political conservativeness inherent in policy recommendations seeking multinational consensus (Herrando-Pérez et al., 2019). However, the latest climate models (CMIP6) show greater future warming than previously predicted (Forster et al., 2020), even if society tracks the needed lower-emissions pathway over the coming decades. Nations have in general not met the goals of the 5 year-old Paris Agreement (United Nations, 2016), and while global awareness and concern have risen, and scientists have proposed major transformative change (in energy production, pollution reduction, custodianship of nature, food production, economics, population policies, etc.), an effective international response has yet to emerge (Ripple et al., 2020). Even assuming that all signatories do, in fact, manage to ratify their commitments (a doubtful prospect), expected warming would still reach 2.6–3.1°C by 2100 (Rogelj et al., 2016) unless large, additional commitments are made and fulfilled. Without such commitments, the projected rise of Earth’s temperature will be catastrophic for biodiversity (Urban, 2015; Steffen et al., 2018; Strona and Bradshaw, 2018) and humanity (Smith et al., 2016).

Regarding international climate-change accords, the Paris Agreement (United Nations, 2016) set the 1.5–2°C target unanimously. But since then, progress to propose, let alone follow, (voluntary) “intended national determined contributions” for post-2020 climate action have been utterly inadequate.

Political Impotence

If most of the world’s population truly understood and appreciated the magnitude of the crises we summarize here, and the inevitability of worsening conditions, one could logically expect positive changes in politics and policies to match the gravity of the existential threats. But the opposite is unfolding. The rise of right-wing populist leaders is associated with anti-environment agendas as seen recently for example in Brazil (Nature, 2018), the USA (Hejny, 2018), and Australia (Burck et al., 2019). Large differences in income, wealth, and consumption among people and even among countries render it difficult to make any policy global in its execution or effect.

A central concept in ecology is density feedback (Herrando-Pérez et al., 2012)—as a population approaches its environmental carrying capacity, average individual fitness declines (Brook and Bradshaw, 2006). This tends to push populations toward an instantaneous expression of carrying capacity that slows or reverses population growth. But for most of history, human ingenuity has inflated the natural environment’s carrying capacity for us by developing new ways to increase food production (Hopfenberg, 2003), expand wildlife exploitation, and enhance the availability of other resources. This inflation has involved modifying temperature via shelter, clothing, and microclimate control, transporting goods from remote locations, and generally reducing the probability of death or injury through community infrastructure and services (Cohen, 1995). But with the availability of fossil fuels, our species has pushed its consumption of nature’s goods and services much farther beyond long-term carrying capacity (or more precisely, the planet’s biocapacity), making the readjustment from overshoot that is inevitable far more catastrophic if not managed carefully (Nyström et al., 2019). A growing human population will only exacerbate this, leading to greater competition for an ever-dwindling resource pool. The corollaries are many: continued reduction of environmental intactness (Bradshaw et al., 2010; Bradshaw and Di Minin, 2019), reduced child health (especially in low-income nations) (Bradshaw et al., 2019), increased food demand exacerbating environmental degradation via agro-intensification (Crist et al., 2017), vaster and possibly catastrophic effects of global toxification (Cribb, 2014; Swan and Colino, 2021), greater expression of social pathologies (Levy and Herzog, 1974) including violence exacerbated by climate change and environmental degradation itself (Agnew, 2013; White, 2017, 2019), more terrorism (Coccia, 2018), and an economic system even more prone to sequester the remaining wealth among fewer individuals (Kus, 2016; Piketty, 2020) much like how cropland expansion since the early 1990s has disproportionately concentrated wealth among the super-rich (Ceddia, 2020). The predominant paradigm is still one of pegging “environment” against “economy”; yet in reality, the choice is between exiting overshoot by design or disaster—because exiting overshoot is inevitable one way or another.

Given these misconceptions and entrenched interests, the continued rise of extreme ideologies is likely, which in turn limits the capacity of making prudent, long-term decisions, thus potentially accelerating a vicious cycle of global ecological deterioration and its penalties. Even the USA’s much-touted New Green Deal (U. S. House of Representatives, 2019) has in fact exacerbated the country’s political polarization (Gustafson et al., 2019), mainly because of the weaponization of ‘environmentalism’ as a political ideology rather than being viewed as a universal mode of self-preservation and planetary protection that ought to transcend political tribalism. Indeed, environmental protest groups are being labeled as “terrorists” in many countries (Hudson, 2020). Further, the severity of the commitments required for any country to achieve meaningful reductions in consumption and emissions will inevitably lead to public backlash and further ideological entrenchments, mainly because the threat of potential short-term sacrifices is seen as politically inopportune. Even though climate change alone will incur a vast economic burden (Burke et al., 2015; Carleton and Hsiang, 2016; Auffhammer, 2018) possibly leading to war (nuclear, or otherwise) at a global scale (Klare, 2020), most of the world’s economies are predicated on the political idea that meaningful counteraction now is too costly to be politically palatable. Combined with financed disinformation campaigns in a bid to protect short-term profits (Oreskes and Conway, 2010; Mayer, 2016; Bakan, 2020), it is doubtful that any needed shift in economic investments of sufficient scale will be made in time.

While uncertain and prone to fluctuate according to unpredictable social and policy trends (Boas et al., 2019; McLeman, 2019; Nature Climate Change, 2019), climate change and other environmental pressures will trigger more mass migration over the coming decades (McLeman, 2019), with an estimated 25 million to 1 billion environmental migrants expected by 2050 (Brown, 2008). Because international law does not yet legally recognize such “environmental migrants” as refugees (United Nations University, 2015) (although this is likely to change) (Lyons, 2020), we fear that a rising tide of refugees will reduce, not increase, international cooperation in ways that will further weaken our capacity to mitigate the crisis.

Changing the Rules of the Game

While it is neither our intention nor capacity in this short Perspective to delve into the complexities and details of possible solutions to the human predicament, there is no shortage of evidence-based literature proposing ways to change human behavior for the benefit of all extant life. The remaining questions are less about what to do, and more about how, stimulating the genesis of many organizations devoted to these pursuits (e.g., ipbes.org, goodanthropocenes.net, overshootday.org, mahb.stanford.edu, populationmatters.org, clubofrome.org, steadystate.org, to name a few). The gravity of the situation requires fundamental changes to global capitalism, education, and equality, which include inter alia the abolition of perpetual economic growth, properly pricing externalities, a rapid exit from fossil-fuel use, strict regulation of markets and property acquisition, reigning in corporate lobbying, and the empowerment of women. These choices will necessarily entail difficult conversations about population growth and the necessity of dwindling but more equitable standards of living.

Conclusions

We have summarized predictions of a ghastly future of mass extinction, declining health, and climate-disruption upheavals (including looming massive migrations) and resource conflicts this century. Yet, our goal is not to present a fatalist perspective, because there are many examples of successful interventions to prevent extinctions, restore ecosystems, and encourage more sustainable economic activity at both local and regional scales. Instead, we contend that only a realistic appreciation of the colossal challenges facing the international community might allow it to chart a less-ravaged future. While there have been more recent calls for the scientific community in particular to be more vocal about their warnings to humanity (Ripple et al., 2017; Cavicchioli et al., 2019; Gardner and Wordley, 2019), these have been insufficiently foreboding to match the scale of the crisis. Given the existence of a human “optimism bias” that triggers some to underestimate the severity of a crisis and ignore expert warnings, a good communication strategy must ideally undercut this bias without inducing disproportionate feelings of fear and despair (Pyke, 2017; Van Bavel et al., 2020). It is therefore incumbent on experts in any discipline that deals with the future of the biosphere and human well-being to eschew reticence, avoid sugar-coating the overwhelming challenges ahead and “tell it like it is.” Anything else is misleading at best, or negligent and potentially lethal for the human enterprise at worst.

Originally published in Frontiers in Conservation Science. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).

“Climate Endgame”: New Peer-Reviewed Paper Explores Catastrophic Climate Change Scenarios

“Climate Endgame”: New Peer-Reviewed Paper Explores Catastrophic Climate Change Scenarios

by | Sep 12, 2022 | NEWS, The Problem: Civilization

Editor’s Note: Global warming is a serious threat to our planet, and, along with mass extinction, wildlife population collapse, habitat destruction, desertification, aquifer drawdown, oceanic dead zones, pollution, and other ecological issues, is one of the primary symptoms of overshoot and industrial civilization.

This paper, published last month in the Proceedings of the National Academy of Sciences, explores the prospect of catastrophic global warming, noting that “There is ample evidence that climate change could become catastrophic… at even modest levels of warming.”

With outcomes such as runaway global warming, oceanic hypoxia, and mass mortality becoming more certain with each passing day, the justifications for Deep Green Resistance are only becoming stronger.

By Luke Kemp, Chi Xu, Joanna Depledge, Kristie L. Ebi, Goodwin Gibbins, Timothy A. Kohler, JohanRockström, Marten Scheffer, Hans Joachim Schellnhuber, Will Steffen, and Timothy M. Lenton. Edited by Kerry Emanuel, Massachusetts Institute of Technology, Cambridge, MA; received May 20, 2021; accepted March 25, 2022

Proceedings of the National Academy of Sciences (USA). 2022 Aug 23;119(34):e2108146119.
doi: 10.1073/pnas.2108146119.

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Prudent risk management requires consideration of bad-to-worst-case scenarios. Yet, for climate change, such potential futures are poorly understood. Could anthropogenic climate change result in worldwide societal collapse or even eventual human extinction? At present, this is a dangerously underexplored topic. Yet there are ample reasons to suspect that climate change could result in a global catastrophe. Analyzing the mechanisms for these extreme consequences could help galvanize action, improve resilience, and inform policy, including emergency responses. We outline current knowledge about the likelihood of extreme climate change, discuss why understanding bad-to-worst cases is vital, articulate reasons for concern about catastrophic outcomes, define key terms, and put forward a research agenda. The proposed agenda covers four main questions: 1) What is the potential for climate change to drive mass extinction events? 2) What are the mechanisms that could result in human mass mortality and morbidity? 3) What are human societies’ vulnerabilities to climate-triggered risk cascades, such as from conflict, political instability, and systemic financial risk? 4) How can these multiple strands of evidence—together with other global dangers—be usefully synthesized into an “integrated catastrophe assessment”? It is time for the scientific community to grapple with the challenge of better understanding catastrophic climate change.

How bad could climate change get? As early as 1988, the landmark Toronto Conference declaration described the ultimate consequences of climate change as potentially “second only to a global nuclear war.” Despite such proclamations decades ago, climate catastrophe is relatively under-studied and poorly understood.

The potential for catastrophic impacts depends on the magnitude and rate of climate change, the damage inflicted on Earth and human systems, and the vulnerability and response of those affected systems. The extremes of these areas, such as high temperature rise and cascading impacts, are underexamined. As noted by the Intergovernmental Panel on Climate Change (IPCC), there have been few quantitative estimates of global aggregate impacts from warming of 3 °C or above (1). Text mining of IPCC reports similarly found that coverage of temperature rises of 3 °C or higher is underrepresented relative to their likelihood (2). Text-mining analysis also suggests that over time the coverage of IPCC reports has shifted towards temperature rise of 2 °C and below https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022EF002876. Research has focused on the impacts of 1.5 °C and 2 °C, and studies of how climate impacts could cascade or trigger larger crises are sparse.

A thorough risk assessment would need to consider how risks spread, interact, amplify, and are aggravated by human responses (3), but even simpler “compound hazard” analyses of interacting climate hazards and drivers are underused. Yet this is how risk unfolds in the real world. For example, a cyclone destroys electrical infrastructure, leaving a population vulnerable to an ensuing deadly heat wave (4). Recently, we have seen compound hazards emerge between climate change and the COVID-19 pandemic (5). As the IPCC notes, climate risks are becoming more complex and difficult to manage, and are cascading across regions and sectors (6).

Why the focus on lower-end warming and simple risk analyses? One reason is the benchmark of the international targets: the Paris Agreement goal of limiting warming to well below 2 °C, with an aspiration of 1.5 °C. Another reason is the culture of climate science to “err on the side of least drama” (7), to not to be alarmists, which can be compounded by the consensus processes of the IPCC (8). Complex risk assessments, while more realistic, are also more difficult to do.

This caution is understandable, yet it is mismatched to the risks and potential damages posed by climate change. We know that temperature rise has “fat tails”: low-probability, high-impact extreme outcomes (9). Climate damages are likely to be nonlinear and result in an even larger tail (10). Too much is at stake to refrain from examining high-impact low-likelihood scenarios. The COVID-19 pandemic has underlined the need to consider and prepare for infrequent, high-impact global risks, and the systemic dangers they can spark. Prudent risk management demands that we thoroughly assess worst-case scenarios.

Our proposed “Climate Endgame” research agenda aims to direct exploration of the worst risks associated with anthropogenic climate change. To introduce it, we summarize existing evidence on the likelihood of extreme climate change, outline why exploring bad-to-worst cases is vital, suggest reasons for catastrophic concern, define key terms, and then explain the four key aspects of the research agenda.

Worst-Case Climate Change

Despite 30 y of efforts and some progress under the United Nations Framework Convention on Climate Change (UNFCCC) anthropogenic greenhouse gas (GHG) emissions continue to increase. Even without considering worst-case climate responses, the current trajectory puts the world on track for a temperature rise between 2.1 °C and 3.9 °C by 2100 (11). If all 2030 nationally determined contributions are fully implemented, warming of 2.4 °C (1.9 °C to 3.0 °C) is expected by 2100. Meeting all long-term pledges and targets could reduce this to 2.1 °C (1.7 °C to 2.6 °C) (12). Even these optimistic assumptions lead to dangerous Earth system trajectories. Temperatures of more than 2 °C above preindustrial values have not been sustained on Earth’s surface since before the Pleistocene Epoch (or more than 2.6 million years ago) (13).

Even if anthropogenic GHG emissions start to decline soon, this does not rule out high future GHG concentrations or extreme climate change, particularly beyond 2100. There are feedbacks in the carbon cycle and potential tipping points that could generate high GHG concentrations (14) that are often missing from models. Examples include Arctic permafrost thawing that releases methane and CO2 (15), carbon loss due to intense droughts and fires in the Amazon (16), and the apparent slowing of dampening feedbacks such as natural carbon sink capacity (17, 18). These are likely to not be proportional to warming, as is sometimes assumed. Instead, abrupt and/or irreversible changes may be triggered at a temperature threshold. Such changes are evident in Earth’s geological record, and their impacts cascaded across the coupled climate–ecological–social system (19). Particularly worrying is a “tipping cascade” in which multiple tipping elements interact in such a way that tipping one threshold increases the likelihood of tipping another (20). Temperature rise is crucially dependent on the overall dynamics of the Earth system, not just the anthropogenic emissions trajectory.

The potential for tipping points and higher concentrations despite lower anthropogenic emissions is evident in existing models. Variability among the latest Coupled Model Intercomparison Project Phase 6 (CMIP6) climate models results in overlap in different scenarios. For example, the top (75th) quartile outcome of the “middle-of-the-road” scenario (Shared Socioeconomic Pathway 3-7.0, or SSP3-7.0) is substantially hotter than the bottom (25th) quartile of the highest emissions (SSP5-8.5) scenario. Regional temperature differences between models can exceed 5 °C to 6 °C, particularly in polar areas where various tipping points can occur (https://www.pnas.org/doi/10.1073/pnas.2108146119#supplementary-materials).

There are even more uncertain feedbacks, which, in a very worst case, might amplify to an irreversible transition into a “Hothouse Earth” state (21) (although there may be negative feedbacks that help buffer the Earth system). In particular, poorly understood cloud feedbacks might trigger sudden and irreversible global warming (22). Such effects remain underexplored and largely speculative “unknown unknowns” that are still being discovered. For instance, recent simulations suggest that stratocumulus cloud decks might abruptly be lost at CO2 concentrations that could be approached by the end of the century, causing an additional ∼8 °C global warming (23). Large uncertainties about dangerous surprises are reasons to prioritize rather than neglect them.

Recent findings on equilibrium climate sensitivity (ECS) (14, 24) underline that the magnitude of climate change is uncertain even if we knew future GHG concentrations. According to the IPCC, our best estimate for ECS is a 3 °C temperature rise per doubling of CO2, with a “likely” range of (66 to 100% likelihood) of 2.5 °C to 4 °C. While an ECS below 1.5 °C was essentially ruled out, there remains an 18% probability that ECS could be greater than 4.5 °C (14). The distribution of ECS is “heavy tailed,” with a higher probability of very high values of ECS than of very low values.

There is significant uncertainty over future anthropogenic GHG emissions as well. Representative Concentration Pathway 8.5 (RCP8.5, now SSP5-8.5), the highest emissions pathway used in IPCC scenarios, most closely matches cumulative emissions to date (25). This may not be the case going forward, because of falling prices of renewable energy and policy responses (26). Yet, there remain reasons for caution. For instance, there is significant uncertainty over key variables such as energy demand and economic growth. Plausibly higher economic growth rates could make RCP8.5 35% more likely (27).

Why Explore Climate Catastrophe?

Why do we need to know about the plausible worst cases? First, risk management and robust decision-making under uncertainty requires knowledge of extremes. For example, the minimax criterion ranks policies by their worst outcomes (28). Such an approach is particularly appropriate for areas characterized by high uncertainties and tail risks. Emissions trajectories, future concentrations, future warming, and future impacts are all characterized by uncertainty. That is, we can’t objectively prescribe probabilities to different outcomes (29). Climate damages lie within the realm of “deep uncertainty”: We don’t know the probabilities attached to different outcomes, the exact chain of cause and effect that will lead to outcomes, or even the range, timing, or desirability of outcomes (, 30). Uncertainty, deep or not, should motivate precaution and vigilance, not complacency.

Catastrophic impacts, even if unlikely, have major implications for economic analysis, modeling, and society’s responses (31, 32). For example, extreme warming and the consequent damages can significantly increase the projected social cost of carbon (31). Understanding the vulnerability and responses of human societies can inform policy making and decision-making to prevent systemic crises. Indicators of key variables can provide early warning signals (33).

Knowing the worst cases can compel action, as the idea of “nuclear winter” in 1983 galvanized public concern and nuclear disarmament efforts. Exploring severe risks and higher-temperature scenarios could cement a recommitment to the 1.5 °C to 2 °C guardrail as the “least unattractive” option (34).

Understanding catastrophic climate scenarios can also inform policy interventions, including last-resort emergency measures like solar radiation management (SRM), the injection of aerosols into the stratosphere to reflect sunlight (35).

Whether to resort to such measures depends on the risk profiles of both climate change and SRM scenarios. One recent analysis of the potential catastrophic risk of stratospheric aerosol injection (SAI) found that the direct and systemic impacts are under-studied (36). The largest danger appears to come from “termination shock”: abrupt and rapid warming if the SAI system is disrupted. Hence, SAI shifts the risk distribution: The median outcome may be better than the climate change it is offsetting, but the tail risk could be worse than warming (36).

There are other interventions that a better understanding of catastrophic climate change could facilitate. For example, at the international level, there is the potential for a “tail risk treaty”: an agreement or protocol that activates stronger commitments and mechanisms when early-warning indicators of potential abrupt change are triggered.

The Potential for Climate Catastrophe

There are four key reasons to be concerned over the potential of a global climate catastrophe. First, there are warnings from history. Climate change (either regional or global) has played a role in the collapse or transformation of numerous previous societies (37) and in each of the five mass extinction events in Phanerozoic Earth history (38). The current carbon pulse is occurring at an unprecedented geological speed and, by the end of the century, may surpass thresholds that triggered previous mass extinctions (39, 40). The worst-case scenarios in the IPCC report project temperatures by the 22nd century that last prevailed in the Early Eocene, reversing 50 million years of cooler climates in the space of two centuries (41).

This is particularly alarming, as human societies are locally adapted to a specific climatic niche. The rise of large-scale, urbanized agrarian societies [editors note: civilization] began with the shift to the stable climate of the Holocene ∼12,000 y ago (42). Since then, human population density peaked within a narrow climatic envelope with a mean annual average temperature of ∼13 °C. Even today, the most economically productive centers of human activity are concentrated in those areas (43). The cumulative impacts of warming may overwhelm societal adaptive capacity.

Second, climate change could directly trigger other catastrophic risks, such as international conflict, or exacerbate infectious disease spread, and spillover risk. These could be potent extreme threat multipliers.

Third, climate change could exacerbate vulnerabilities and cause multiple, indirect stresses (such as economic damage, loss of land, and water and food insecurity) that coalesce into system-wide synchronous failures. This is the path of systemic risk. Global crises tend to occur through such reinforcing “synchronous failures” that spread across countries and systems, as with the 2007–2008 global financial crisis (44). It is plausible that a sudden shift in climate could trigger systems failures that unravel societies across the globe.

The potential of systemic climate risk is marked: The most vulnerable states and communities will continue to be the hardest hit in a warming world, exacerbating inequities. Fig. 1 shows how projected population density intersects with extreme >29 °C mean annual temperature (MAT) (such temperatures are currently restricted to only 0.8% of Earth’s land surface area). Using the medium-high scenario of emissions and population growth (SSP3-7.0 emissions, and SSP3 population growth), by 2070, around 2 billion people are expected to live in these extremely hot areas. Currently, only 30 million people live in hot places, primarily in the Sahara Desert and Gulf Coast (43).

Fig. 1.

Overlap between future population distribution and extreme heat. CMIP6 model data [from nine GCM models available from the WorldClim database (45)] were used to calculate MAT under SSP3-7.0 during around 2070 (2060–2080) alongside Shared SSP3 demographic projections to ∼2070 (46). The shaded areas depict regions where MAT exceeds 29 °C, while the colored topography details the spread of population density.

Extreme temperatures combined with high humidity can negatively affect outdoor worker productivity and yields of major cereal crops. These deadly heat conditions could significantly affect populated areas in South and southwest Asia (47).

Fig. 2 takes a political lens on extreme heat, overlapping SSP3-7.0 or SSP5-8.5 projections of >29 °C MAT circa 2070, with the Fragile States Index (a measurement of the instability of states). There is a striking overlap between currently vulnerable states and future areas of extreme warming. If current political fragility does not improve significantly in the coming decades, then a belt of instability with potentially serious ramifications could occur.

Fig. 2.

Fragile heat: the overlap between state fragility, extreme heat, and nuclear and biological catastrophic hazards. GCM model data [from the WorldClim database (45)] was used to calculate mean annual warming rates under SSP3-7.0 and SSP5-8.5. This results in a temperature rise of 2.8 °C in ∼2070 (48) for SSP3-7.0, and 3.2 °C for SSP5-8.5. The shaded areas depict regions where MAT exceeds 29 °C. These projections are overlapped with the 2021 Fragile State Index (FSI) (49). This is a necessarily rough proxy because FSI only estimates current fragility levels. While such measurements of fragility and stability are contested and have limitations, the FSI provides one of the more robust indices. This Figure also identifies the capitals of states with nuclear weapons, and the location of maximum containment Biosafety Level 4 (BS4) laboratories which handle the most dangerous pathogens in the world. These are provided as one rough proxy for nuclear and biological catastrophc hazards.

Finally, climate change could irrevocably undermine humanity’s ability to recover from another cataclysm, such as nuclear war. That is, it could create significant latent risks (Table 1): Impacts that may be manageable during times of stability become dire when responding to and recovering from catastrophe. These different causes for catastrophic concern are interrelated and must be examined together.

Table 1. Defining key terms in the Climate Endgame agenda

Term Definition
Latent risk Risk that is dormant under one set of conditions but becomes active under another set of conditions.
Risk cascade Chains of risk occurring when an adverse impact triggers a set of linked risks (3).
Systemic risk The potential for individual disruptions or failures to cascade into a system-wide failure.
Extreme climate change Mean global surface temperature rise of 3 °C or more above preindustrial levels by 2100.
Extinction risk The probability of human extinction within a given timeframe.
Extinction threat A plausible and significant contributor to total extinction risk.
Societal fragility The potential for smaller damages to spiral into global catastrophic or extinction risk due to societal vulnerabilities, risk cascades, and maladaptive responses.
Societal collapse Significant sociopolitical fragmentation and/or state failure along with the relatively rapid, enduring, and significant loss capital, and systems identity; this can lead to large-scale increases in mortality and morbidity.
Global catastrophic risk The probability of a loss of 25% of the global population and the severe disruption of global critical systems (such as food) within a given timeframe (years or decades).
Global catastrophic threat A plausible and significant contributor to global catastrophic risk; the potential for climate change to be a global catastrophic threat can be referred to as “catastrophic climate change”.
Global decimation risk The probability of a loss of 10% (or more) of global population and the severe disruption of global critical systems (such as food) within a given timeframe (years or decades).
Global decimation threat A plausible and significant contributor to global decimation risk.
Endgame territory Levels of global warming and societal fragility that are judged sufficiently probable to constitute climate change as an extinction threat.
Worst-case warming The highest empirically and theoretically plausible level of global warming.

Defining the Key Terms

Although bad-to-worst case scenarios remain underexplored in the scientific literature, statements labeling climate change as catastrophic are not uncommon. UN Secretary-General António Guterres called climate change an “existential threat.” Academic studies have warned that warming above 5 °C is likely to be “beyond catastrophic” (50), and above 6 °C constitutes “an indisputable global catastrophe” (9).Current discussions over climate catastrophe are undermined by unclear terminology. The term “catastrophic climate change” has not been conclusively defined. An existential risk is usually defined as a risk that cause an enduring and significant loss of long-term human potential (51, 52). This existing definition is deeply ambiguous and requires societal discussion and specification of long-term human values (52). While a democratic exploration of values is welcome, it is not required to understand pathways to human catastrophe or extinction (52). For now, the existing definition is not a solid foundation for a scientific inquiry.We offer clarified working definitions of such terms in Table 1. This is an initial step toward creating a lexicon for global calamity. Some of the terms, such as what constitutes a “plausible” risk or a “significant contributor,” are necessarily ambiguous. Others, such as thresholding at 10% or 25% of global population, are partly arbitrary (10% is intended as a marker for a precedented loss, and 25% is intended as an unprecedented decrease; see SI Appendix for further discussion). Further research is needed to sharpen these definitions. The thresholds for global catastrophic and decimation risks are intended as general heuristics and not concrete numerical boundaries. Other factors such as morbidity, and cultural and economic loss, need to be considered.

We define risk as the probability that exposure to climate change impacts and responses will result in adverse consequences for human or ecological systems. For the Climate Endgame agenda, we are particularly interested in catastrophic consequences. Any risk is composed of four determinants: hazard, exposure, vulnerability, and response (3).

We have set global warming of 3 °C or more by the end of the century as a marker for extreme climate change. This threshold is chosen for four reasons: Such a temperature rise well exceeds internationally agreed targets, all the IPCC “reasons for concern” in climate impacts are either “high” or “very high” risk between 2 °C and 3 °C, there are substantially heightened risks of self-amplifying changes that would make it impossible to limit warming to 3 °C, and these levels relate to far greater uncertainty in impacts.

Key Research Thus Far

The closest attempts to directly study or comprehensively address how climate change could lead to human extinction or global catastrophe have come through popular science books such as The Uninhabitable Earth (53) and Our Final Warning (10). The latter, a review of climate impacts at different degrees, concludes that a global temperature rise of 6 °C “imperils even the survival of humans as a species” (10).

We know that health risks worsen with rising temperatures (54). For example, there is already an increasing probability of multiple “breadbasket failures” (causing a food price shock) with higher temperatures (55). For the top four maize-producing regions (accounting for 87% of maize production), the likelihood of production losses greater than 10% jumps from 7% annually under a 2 °C temperature rise to 86% under 4 °C (56). The IPCC notes, in its Sixth Assessment Report, that 50 to 75% of the global population could be exposed to life-threatening climatic conditions by the end of the century due to extreme heat and humidity (6). SI Appendix provides further details on several key studies of extreme climate change.

The IPCC reports synthesize peer-reviewed literature regarding climate change, impacts and vulnerabilities, and mitigation. Despite identifying 15 tipping elements in biosphere, oceans, and cryosphere in the Working Group 1 contribution to the Sixth Assessment Report, many with irreversible thresholds, there were very few publications on catastrophic scenarios that could be assessed. The most notable coverage is the Working Group II “reasons for concern” syntheses that have been reported since 2001. These syntheses were designed to inform determination of what is “dangerous anthropogenic interference” with the climate system, that the UNFCCC aims to prevent. The five concerns are unique and threatened ecosystems, frequency and severity of extreme weather events, global distribution and balance of impacts, total economic and ecological impact, and irreversible, large-scale, abrupt transitions. Each IPCC assessment found greater risks occurring at lower increases in global mean temperatures. In the Sixth Assessment Report, all five concerns were listed as very high for temperatures of 1.2 °C to 4.5 °C. In contrast, only two were rated as very high at this temperature interval in the previous Assessment Report (6). All five concerns are now at “high” or “very high” for 2 °C to 3 °C of warming (57).

A Sample Research Agenda: Extreme Earth System States, Mass Mortality, Societal Fragility, and Integrated Climate Catastrophe Assessments

We suggest a research agenda for catastrophic climate change that focuses on four key strands:

  • Understanding extreme climate change dynamics and impacts in the long term
  • Exploring climate-triggered pathways to mass morbidity and mortality
  • Investigating social fragility: vulnerabilities, risk cascades, and risk responses
  • Synthesizing the research findings into “integrated catastrophe assessments”

Our proposed agenda learns from and builds on integrated assessment models that are being adapted to better assess large-scale harms. A range of tipping points have been assessed (58–60), with effects varying from a 10% chance of doubling the social cost of carbon (61) up to an eightfold increase in the optimal carbon price (60). This echoes earlier findings that welfare estimates depend on fat tail risks (31). Model assumptions such as discount rates, exogenous growth rates, risk preferences, and damage functions also strongly influence outcomes.

There are large, important aspects missing from these models that are highlighted in the research agenda: longer-term impacts under extreme climate change, pathways toward mass morbidity and mortality, and the risk cascades and systemic risks that extreme climate impacts could trigger. Progress in these areas would allow for more realistic models and damage functions and help provide direct estimates of casualties (62), a necessary moral noneconomic measure of climate risk. We urge the research community to develop integrated conceptual and semiquantitative models of climate catastrophes.

Finally, we invite other scholars to revise and improve upon this proposed agenda.

Extreme Earth System States.

We need to understand potential long-term states of the Earth system under extreme climate change. This means mapping different “Hothouse Earth” scenarios (21) or other extreme scenarios, such as alternative circulation regimes or large, irreversible changes in ice cover and sea level. This research will require consideration of long-term climate dynamics and their impacts on other planetary-level processes. Research suggests that previous mass extinction events occurred due to threshold effects in the carbon cycle that we could cross this century (40, 63). Key impacts in previous mass extinctions, such as ocean hypoxia and anoxia, could also escalate in the longer term (40, 64).

Studying potential tipping points and irreversible “committed” changes of ecological and climate systems is essential. For instance, modeling of the Antarctic ice sheet suggests there are several tipping points that exhibit hysteresis (65). Irreversible loss of the West Antarctic ice sheet was found to be triggered at ∼2 °C global warming, and the current ice sheet configuration cannot be regained even if temperatures return to present-day levels. At a 6 °C to 9 °C rise in global temperature, slow, irreversible loss of the East Antarctic ice sheet and over 40 m of sea level rise equivalent could be triggered (65). Similar studies of areas such as the Greenland ice sheet, permafrost, and terrestrial vegetation would be helpful. Identifying all the potential Earth system tipping elements is crucial. This should include a consideration of wider planetary boundaries, such as biodiversity, that will influence tipping points (66), feedbacks beyond the climate system, and how tipping elements could cascade together (67).

Mass Morbidity and Mortality.

There are many potential contributors to climate-induced morbidity and mortality, but the “four horsemen” of the climate change end game are likely to be famine and undernutrition, extreme weather events, conflict, and vector-borne diseases. These will be worsened by additional risks and impacts such as mortality from air pollution and sea level rise.

These pathways require further study. Empirical estimates of even direct fatalities from heat stress thus far in the United States are systematically underestimated (68). A review of the health and climate change literature from 1985 to 2013 (with a proxy review up to 2017) found that, of 2,143 papers, only 189 (9%) included a dedicated discussion of more-extreme health impacts or systemic risk (relating to migration, famine, or conflict) (69). Models also rarely include adaptive responses. Thus, the overall mortality estimates are uncertain.

How can potential mass morbidity and mortality be better accounted for? 1) Track compound hazards through bottom-up modeling of systems and vulnerabilities (70) and rigorously stress test preparedness (71). 2) Apply models to higher-temperature scenarios and longer timelines. 3) Integrate risk cascades and systemic risks (see the following section) into health risk assessments, such as by incorporating morbidity and mortality resulting from a climate-triggered food price shock.

Societal Fragility: Vulnerabilities, Risk Cascades, and Risk Responses.

More-complex risk assessments are generally more realistic. The determinants of risk are not just hazards, vulnerabilities, and exposures, but also responses (3, 72). A complete risk assessment needs to consider climate impacts, differential exposure, systemic vulnerabilities, responses of societies and actors, and the knock-on effects across borders and sectors (73), potentially resulting in systemic crises. In the worst case(s), a domino effect or spiral could continuously worsen the initial risk.

Societal risk cascades could involve conflict, disease, political change, and economic crises. Climate change has a complicated relationship with conflict, including, possibly, as a risk factor (74) especially in areas with preexisting ethnic conflict (75). Climate change could affect the spread and transmission of infectious diseases, as well as the expansion and severity of different zoonotic infections (76), creating conditions for novel outbreaks and infections (6,77). Epidemics can, in turn, trigger cascading impacts, as in the case of COVID-19. Exposure to ecological stress and natural disasters are key determinants for the cultural “tightness” (strictness of rules, adherence to tradition, and severity of punishment) of societies (78). The literature on the median economic damages of climate change is profuse, but there is far less on financial tail risks, such as the possibility of global financial crises.

Past studies could be drawn upon to investigate societal risk. Relatively small, regional climate changes are linked to the transformation and even collapse of previous societies (79, 80). This could be due to declining resilience and the passing of tipping points in these societies. There is some evidence for critical slowing down in societies prior to their collapse (81, 82). However, care is needed in drawing lessons from premodern case studies. Prehistory and history should be studied to determine not just how past societies were affected by specific climate hazards but how those effects differ as societies change with respect to, for example, population density, wealth inequality, and governance regime. Such framing will allow past and current societies to be brought under a single system of analysis (37).

The characteristics and vulnerabilities of a modern globalized world where food and transport distribution systems can buffer against traumas will need to feature in work on societal sensitivity. Such large, interconnected systems bring their own sources of fragility, particularly if networks are relatively homogeneous, with a few dominant nodes highly connected to everyone else (83). Other important modern-day vulnerabilities include the rapid spread of misinformation and disinformation. These epistemic risks are serious concerns for public health crises (84) and have already hindered climate action. A high-level and simplified depiction of how risk cascades could unfold is provided in Fig. 3.

Fig. 3.

Cascading global climate failure. This is a causal loop diagram, in which a complete line represents a positive polarity (e.g., amplifying feedback; not necessarily positive in a normative sense) and a dotted line denotes a negative polarity (meaning a dampening feedback). See SI Appendix for further information.

Integrated Catastrophic Assessments.

Climate change will unfold in a world of changing ecosystems, geopolitics, and technology. Could we even see “warm wars”—technologically enhanced great power conflicts over dwindling carbon budgets, climate impacts, or SRM experiments? Such developments and scenarios need to be considered to build a full picture of climate dangers. Climate change could reinforce other interacting threats, including rising inequality, demographic stresses, misinformation, new destructive weapons, and the overshoot of other planetary boundaries (85). There are also natural shocks, such as solar flares and high-impact volcanic eruptions, that present possible deadly synchronicities (86). Exploring these is vital, and a range of “standardized catastrophic scenarios” would facilitate assessment.

Expert elicitation, systems mapping, and participatory scenarios provide promising ways of understanding such cascades (73). There are also existing research agendas for some of these areas that could be funded (87).

Integration can be approached in several ways. Metareviews and syntheses of research results can provide useful data for mapping the interactions between risks. This could be done through causal mapping, expert elicitation, and agent-based or systems dynamics modeling approaches. One recent study mapped the evidence base for relationships between climate change, food insecurity, and contributors to societal collapse (mortality, conflict, and emigration) based on 41 studies (88).

A particularly promising avenue is to repurpose existing complex models to study cascading risks. The resulting network could be “stress tested” with standardized catastrophic scenarios. This could help estimate which areas may incur critical shortages or disruptions, or drastic responses (such as food export bans). Complex models have been developed to help understand past large-scale systemic disasters, such as the 2007–2008 global financial crisis (89). Some of these could be repurposed for exploring the potential nature of a future global climate crisis.

Systems failure is unlikely to be globally simultaneous; it is more likely to begin regionally and then cascade up. Although the goal is to investigate catastrophic climate risk globally, incorporating knowledge of regional losses is indispensable.

The potentially catastrophic risks of climate change are difficult to quantify, even within models. Any of the above-mentioned modeling approaches should provide a greater understanding of the pathways of systemic risk, and rough probabilistic guides. Yet the results could provide the foundation for argumentation-based tools to assess the potential for catastrophic outcomes under different levels of temperature rise (90). These should be fed into open deliberative democratic methods that provide a fair, inclusive, and effective approach to decision-making (91). Such approaches could draw on decision-making tools under uncertainty, such as the minimax principle or ranking decisions by the weighted sum of their best and worst outcomes, as suggested in the Dasgupta review of biodiversity (92).

An IPCC Special Report on Catastrophic Climate Change

The IPCC has yet to give focused attention to catastrophic climate change. Fourteen special reports have been published. None covered extreme or catastrophic climate change. A special report on “tipping points” was proposed for the seventh IPCC assessment cycle, and we suggest this could be broadened to consider all key aspects of catastrophic climate change. This appears warranted, following the IPCC’s decision framework (93). Such a report could investigate how Earth system feedbacks could alter temperature trajectories, and whether these are irreversible.

A special report on catastrophic climate change could help trigger further research, just as the “Global warming of 1.5 °C” special report (94) did. That report also galvanized a groundswell of public concern about the severity of impacts at lower temperature ranges. The impact of a report on catastrophic climate change could be even more marked. It could help bring into focus how much is at stake in a worst-case scenario. Further research funding of catastrophic and worst-case climate change is critical.

Effective communication of research results will be key. While there is concern that fear-invoking messages may be unhelpful and induce paralysis (95), the evidence on hopeful vs. fearful messaging is mixed, even across metaanalyses (96, 97). The role of emotions is complex, and it is strategic to adjust messages for specific audiences (98). One recent review of the climate debate highlighted the importance of avoiding political bundling, selecting trusted messengers, and choosing effective frames (99). These kinds of considerations will be crucial in ensuring a useful and accurate civic discussion.

Conclusions

There is ample evidence that climate change could become catastrophic. We could enter such “endgames” at even modest levels of warming. Understanding extreme risks is important for robust decision-making, from preparation to consideration of emergency responses. This requires exploring not just higher temperature scenarios but also the potential for climate change impacts to contribute to systemic risk and other cascades. We suggest that it is time to seriously scrutinize the best way to expand our research horizons to cover this field. The proposed “Climate Endgame” research agenda provides one way to navigate this under-studied area. Facing a future of accelerating climate change while blind to worst-case scenarios is naive risk management at best and fatally foolish at worst.

This open-access scientific paper was published in the Proceedings of the National Academy of Sciences under a Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND) or a Creative Commons Attribution (CC BY) license.

Appendix and references available here: https://www.pnas.org/doi/abs/10.1073/pnas.2108146119

Photo by Malcolm Lightbody on Unsplash.

Krill, The Most Abundant Species on Earth and Key Food Source for Whales, Are in Trouble

Krill, The Most Abundant Species on Earth and Key Food Source for Whales, Are in Trouble

by | Sep 9, 2022 | NEWS, The Problem: Civilization

Editor’s note: By biomass, krill are the most abundant species in the world and the main food source for all baleen whales — including blue whales, the largest animals on the planet and the largest ever known to have existed.

Regardless of how abundant it is — see Passenger Pigeons, Buffalo, or Great Auks — any species that becomes economically valuable in a growth economy will likely experience decline and collapse. That is the nature of endless growth.

Krill are no different. Between overfishing that has more than quadrupled in 15 years and global climate destabilization that has already warmed the Antarctic by 2.5° C since the 1940s, Krill, like all life on Earth, are in trouble —  yet another sign that industrial civilization is driving an ongoing ecological collapse and accelerating us deeper into the 6th mass extinction (an extermination, in this case) of life on Earth.

by / Mongabay

  • Antarctic krill are one of the most abundant species in the world in terms of biomass, but scientists and conservationists are concerned about the future of the species due to overfishing, climate change impacts and other human activities.
  • Krill fishing has increased year over year as demand rises for the tiny crustaceans, which are used as feed additives for global aquaculture and processed for krill oil.
  • Experts have called on the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), the group responsible for protecting krill, to update its rules to better protect krill; others are calling for a moratorium on krill fishing.
  • Antarctic krill play a critical role in maintaining the health of our planet by storing carbon and providing food for numerous species.

Antarctic krill — tiny, filter-feeding crustaceans that live in the Southern Ocean — have long existed in mind-boggling numbers. A 2009 study estimated that the species has a biomass of between 300 million and 500 million metric tons, which is more than any other multicellular wild animal in the world. Not only are these teensy animals great in number, but they’re known to lock away large quantities of carbon through their feeding and excrement cycles. One study estimates that krill remove 23 million metric tons of carbon each year — about the amount of carbon produced by 35 million combustion-engine cars — while another suggests that krill take away 39 million metric tons each year. Krill are also a main food source for many animals for which Antarctica is famous: whales, seals, fish, penguins, and a range of other seabirds.

But Antarctic krill (Euphausia superba) are not “limitless,” as they were once described in the 1960s; they’re a finite resource under an increasing amount of pressure due to overfishing, pollution, and climate change impacts like the loss of sea ice and ocean acidification. While krill are nowhere close to being threatened with extinction, the 2022 report from the Intergovernmental Panel on Climate Change indicated that there’s a high likelihood that climate-induced stressors would present considerable risks for the global supply of krill.

“Warming that is occurring along the Antarctic Peninsula and Scotia Sea has caused the krill stocks in those areas to shrink and the center of that population has moved southwards,” Kim Bernard, a marine ecologist at Oregon State University, wrote to Mongabay via email while stationed in the Antarctic Peninsula. “This tells us already that krill numbers aren’t endless.”

Concerns are amassing around one place in particular: a krill hotspot and nursery at the tip of the Antarctic Peninsula known as “Area 48,” which harbors about 60 million metric tons of krill. Not only has this area become a key foraging ground for many species that rely on krill, but it also attracts about a dozen industrial fishing vessels each year. The amount of krill they catch has been steadily increasing over the years. In 2007, vessels caught 104,728 metric tons in Area 48; in 2020, they caught 450,781 metric tons.

The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), the group responsible for protecting krill, has imposed rules to try and regulate krill fishing in the Southern Ocean, but many conservationists and scientists say the rules need to be updated to reflect the changing dynamics of the marine environment. That said, many experts argue that the Antarctic krill fishery can be sustainable if managed correctly.

krill

Antarctic krill are under pressure due to overfishing, pollution, and climate change impacts like the loss of sea ice and ocean acidification. Image courtesy of Dan Costa.

Approaching krill ‘trigger level’

Fishing nations started casting their nets for Antarctic krill in the 1970s, believing these small crustaceans could provide a valuable source of animal protein that would alleviate world hunger. But in the 1980s, interest in krill fishing waned, partly because no one was sure how to remove the high levels of fluoride in their exoskeletons. It was also generally difficult to process krill into food fit for human consumption and to successfully sell these foods to consumers.

But krill fishing never really stopped. In fact, it’s been gaining momentum ever since krill was identified as a suitable animal feed. Now krill is mainly used as a feed additive in the global aquaculture industry, as well as to produce krill oil that goes into omega-3 dietary supplements.

In 1982, the CCAMLR was established to address concerns that the Antarctic krill fishery could have a substantial impact on the marine ecosystem of the Southern Ocean. In 2010, the CCAMLR established a rule limiting catches to 5.61 million metric tons across four subsections of Area 48 where krill fishing was concentrated. The rule also dictated that krill fishing in these areas must stop if the total combined catch reached a “trigger level” of 620,000 metric tons.

So far, total catches have not exceeded this boundary. But krill fishing nations, which currently include Norway, China, South Korea, Ukraine and Chile, are inching closer to it as they expand their operations.

“As long as catches were significantly below the trigger level, I think people felt like, ‘Oh, we don’t need to be too worried,’” Claire Christian, executive director of the Antarctic and Southern Ocean Coalition (ASOC), told Mongabay. “They’re still not there yet, but as they’ve been getting closer, there’s been more pressure on CCAMLR scientists and policymakers to look at the fishery and develop a more comprehensive management system.”

Stuart Corney, an Antarctic krill expert at the University of Tasmania, said a primary concern is that most krill fishing is concentrated at the tip of the Antarctic Peninsula, where krill are known to spawn, creating “localized depletion.”

“If we overexploit the krill in that region, it can have significant implications for the population in a greater area of Antarctica …  so it needs to be carefully managed efficiently,” Corney told Mongabay.

Another issue with the current catch limits is that they don’t consider the impacts of climate change, according to Bernard.

“This is particularly important at the Antarctic Peninsula where the fishing effort is greatest because the Antarctic Peninsula is one of the most rapidly warming regions on the planet,” Bernard said. “There is also evidence that areas along the Antarctic Peninsula such as the Gerlache Strait are important overwintering grounds for Antarctic krill, particularly for the juveniles and larvae that shelter in the bays and fjords along the Peninsula at that time of year. There is no seasonal closure on the krill fishery and because of delayed sea ice formation in the region around the Gerlache Strait the fishery can extend into winter. When that happens, the fishery could remove massive numbers from the next reproductive cohort of the population.”

Krill are known to lock away large amounts of carbon through their feeding and excrement cycles. Image courtesy of Aker.

Not only will global heating deplete the sea ice that krill depend upon, but research has suggested that warming waters will impact krill growth, possibly leading to a 40% decline in the mass of individual krill by the end of the century. Other research has argued that ocean acidification, another impact of climate change, will reduce krill development and hatchling rate and lead to an eventual collapse in 2300.

Progress and setbacks

In 2019, CCAMLR members agreed on a scientific work plan with the view of adopting new conservation measures based on it in 2021. This process was delayed due to COVID-19, but CCAMLR members are expected to reinvigorate these discussions at the next meeting in October, said Nicole Bransome, a marine ecologist at Pew Bertarelli Ocean Legacy.

“Hopefully, the scientists will have been able to put all of the science together … and come up with a new measure that spreads the catch out in space to reduce the impacts on predators,” Bransome told Mongabay. However, she said she’s concerned about a possible move to increase krill catch limits, which was discussed at last year’s meeting.

“Preliminary analysis suggests that the overall catch level could go up, but as of last year’s meeting, there were still a lot of uncertainties with that model and the parameters used in that model,” she said. “We would rather see that if the catch limits change, they’re based on a robust model and good science.”

While many experts say krill fishing can be sustainable if managed correctly, others call for stronger measures to protect krill.

Over the past decade, conservationists and scientists have been proposing the establishment of three new marine protected areas (MPAs) in East Antarctica, the Antarctic Peninsula and the Weddell Sea, ranging over 4 million square kilometers (1.5 million square miles) of the Southern Ocean, which would help protect krill with no-take zones.

“There is now strong scientific evidence that we need strict protection of at least 30% of the global ocean to effectively protect it,” said Christian of ASOC.

Yet the CCAMLR, which makes decisions based on consensus, has rejected the MPA proposal year after year.

Sophie Nodzenski, a senior campaigner at the Changing Markets Foundation, an NGO that works to expose irresponsible corporate practices and to foster sustainability, said the CCAMLR’s continued rejection of the MPAs had led her organization to call for a moratorium on krill fishing. (The Bob Brown Foundation, an Australian NGO that works to protect the natural world, has previously called for a similar ban on krill fishing to be put in place.)

“We are aware it’s a strong stand,” Nodzenski told Mongabay. “But there is a climate emergency, and there is a worry about how krill fishing is exacerbating the threats from climate change. So why don’t we just put a moratorium in place?”

In a report released Aug. 11 — for the first World Krill Day — the Changing Market Foundation details concerns for the planned expansion of the krill industry, which could push catch limits past the current trigger points. It also reveals how Norwegian company Aker Biomarine dominates the industry, supplying krill feed for farmed salmon operations around the world.

Consumers could alleviate pressure on krill “by pushing for a change in the way we are harvesting krill,” Nodzenski said. “If there’s less demand for products, eventually you could see a knock-on effect on the krill harvesting.”

krill

Krill is fished so it can be used as a feed additive in the global aquaculture industry, as well as to produce krill oil that goes into omega-3 dietary supplements. Image courtesy of Pete Harmsen.

Is change coming?

The report also casts doubt on the CCAMLR’s ability to make timely decisions to protect krill.

“This is because CCAMLR’s decision-making process is based on consensus; as long as some members oppose changes to the status quo (in this regard, China and Russia), decisions cannot go ahead,” the authors write. “This means that, for the foreseeable future, it is difficult to envisage how management measures regarding krill can evolve and adapt to our rapidly changing climate.”

Yet other experts say the CCAMLR has the capacity to authorize effective changes.

“CCAMLR has a range of mechanisms it can use to further ecosystem protection,” Bransome of Pew Bertarelli Ocean Legacy said. “Lots of progress has been made … and we are looking to CCAMLR to achieve additional protections at the upcoming CCAMLR meeting.”

Corney from the University of Tasmania said he believes it’s important for fishing nations to continue working together through the CCAMLR to protect the Southern Ocean.

“If some nations started pulling out of CCAMLR … they’re not bound by the rules [and] they can do their thing,” Corney said. “We want all nations to remain in CCAMLR. We want them to sign up for the agreements that are reached. That means we have to accept the structure that is there.”

While opinions differ about how to manage the krill fishery, experts tend to agree on one thing: krill are too valuable to lose in this moment of climate crisis.

krill

Antarctic krill are also a main food source for many animals, including whales, seals, fish, penguins, and a range of other seabirds. Image by Brett Wilks /Australian Antarctic Division.

“Even though Antarctic krill are seemingly far removed from our lives, some of that excess carbon dioxide we’ve pumped into the air is exported to the sea floor by krill, where it will remain for thousands of years,” Bernard said. “Without Antarctic krill, Earth would be even hotter than it already is.”

Citations:

Atkinson, A., Siegel, V., Pakhomov, E. A., Jessopp, M. J., & Loeb, V. (2009). A re-appraisal of the total biomass and annual production of Antarctic krill. Deep Sea Research Part I: Oceanographic Research Papers, 56(5), 727-740. doi:10.1016/j.dsr.2008.12.007

Tarling, G. A., & Thorpe, S. E. (2017). Oceanic swarms of Antarctic krill perform satiation sinking. Proceedings of the Royal Society B: Biological Sciences, 284(1869), 20172015. doi:10.1098/rspb.2017.2015

Belcher, A., Henson, S. A., Manno, C., Hill, S. L., Atkinson, A., Thorpe, S. E., … Tarling, G. A. (2019). Krill faecal pellets drive hidden pulses of particulate organic carbon in the marginal ice zone. Nature Communications, 10(1). doi:10.1038/s41467-019-08847-1

Spiller, J. (2016). Frontiers for the American century: Outer space, Antarctica, and cold war nationalism. Springer.

Pörtner, H., Roberts, D. C., Tignor, M., Poloczanska, E. S., Mintenbeck, K., Alegría, A., … Rama, B. (Eds.) (2022). Climate Change 2022: Impacts, Adaptation and Vulnerability. Retrieved from IPCC website: https://www.ipcc.ch/report/ar6/wg2/

Klein, E. S., Hill, S. L., Hinke, J. T., Phillips, T., & Watters, G. M. (2018). Impacts of rising sea temperature on krill increase risks for predators in the Scotia Sea. PLOS ONE, 13(1), e0191011. doi:10.1371/journal.pone.0191011

Kawaguchi, S., Ishida, A., King, R., Raymond, B., Waller, N., Constable, A., … Ishimatsu, A. (2013). Risk maps for Antarctic krill under projected Southern Ocean acidification. Nature Climate Change, 3(9), 843-847. doi:10.1038/nclimate1937

Changing Markets Foundation. (2022). Krill, Baby, Krill: The corporations profiting from plundering Antarctica. Retrieved from https://changingmarkets.org/portfolio/fishing-the-feed/

Banner image caption: Antarctic krill. Image courtesy of Dan Costa.

Elizabeth Claire Alberts is a staff writer for Mongabay. Follow her on Twitter @ECAlberts.