Sawing Off the Limb
“Indeed, grossly disrupting global ecological balances, as we have been recklessly doing of late ... is akin to slowly and unwittingly sawing off the limb on which humanity itself perches.”
At the top of the list of human activities that severely degrade vibrant, diverse, resilient ecosystems is industrial agriculture. This should not be surprising as agriculture it is the largest interface between humans and the environment. It is also the prime beneficiary of the nature-dominating totalitarian logic that pervades our current corporate-supremacy economic worldview.
Land conversion for agriculture destroys habitat, increases soil erosion, and accelerates loss of species diversity. About 12 percent of our current land surface is under crop cultivation. Much of this land degrades over time, and we are already exceeding the regenerative capacity of the Earth’s soil resources. Approximately 40 percent of cultivated land is experiencing soil erosion, reduction in fertility, or overgrazing. Fertile soils are being converted into vast swathes of lifeless dirt.
Soil loss rates exceed soil formation rates by at least tenfold. The conversion of land in the Amazon rainforest for cattle ranching and for feed could tip the basin into an irreversible transformation to a semi-arid savanna, that in turn triggers unpredictable changes to the global climate system.
Insects are globally dying en masse, risking a catastrophic collapse of Earth’s delicate, interdependent ecosystems that could present a real existential threat to the survival of human civilization. This alarming insect apocalypse is being driven by habitat loss because of intensive agriculture, the heavy use of pesticides, climate change, and invasive species. More than 40 percent of insect species are dwindling globally and a third of species are endangered. The total mass of insects is falling by 2.5 percent annually. If the decline continues at this rate, insects could be wiped off the face of the Earth within a century.
The proportion of insects in decline is currently twice as high as that of vertebrates and the insect extinction rate is eight times faster than that of mammals, birds, and reptiles. Of course, insects play a critical role in the proper functioning of Earth’s ecosystems. They are a food source for many animals, critical pollinators, and recyclers of nutrients back into the soil.
A world with no insects would be a flowerless and less vibrant world, a world of still and silent forests, a world of dung and old leaves and rotting carcasses accumulating in cities and roadsides. Basically, biological annihilation.
Over the past 10,000 years, the biomass of wild animals has been dramatically decimated, while human and livestock numbers have skyrocketed. In just the last 50 years, animal populations have fallen by 68 percent. The tropical Americas have seen animal populations decline 94 percent in the same period. The size of observed animal communities in or near freshwater globally have fallen by 84 percent.
By mass, humans and domesticated livestock now make up 97 percent of all animals on land. Wild mammals and birds (elephants, mice, kangaroos, lions, raccoons, bats, bears, deer, wolves, moose, chickadees, herons, eagles, etc.) have been reduced to a mere 3 percent. The biomass of chickens (livestock) alone is more than double the total mass of all other birds combined. Food production and other human activities are destroying the ecosystems other animals rely upon.
Before the advent of agriculture 10,000 years ago, humans made up just a tiny fraction of animal biomass, and domesticated livestock did not exist at all. With this massive loss of mammals, birds, amphibians, reptiles, and fish goes the security of ecosystems that have always supported humanity.
As a result of decades of unsustainable business-as-usual commercial fishing practices, peak fish may have occurred in 1996, as global marine catches have been declining ever since. Since 1950 we've wiped out around 90 percent of the big fish in the ocean — swordfish, marlin, and grouper.
Upwards of a quarter million sharks are killed each day, mostly for just their fins, to bolster the status of the soups they are destined for. What does it say that just one bluefin tuna can bring hundreds of thousands of dollars on the Japanese fish market?
Every year, an undersea area twice the size of the continental United States is plowed by industrial megatrawlers, callously leveling everything on the sea floor in a relentless quest to keep up the catch — and profits.
Not surprisingly, more than half of all of the fish eaten worldwide today is produced through aquaculture — underwater meat production. But each pound of farm-raised salmon costs fifteen pounds of fish from the ocean. Anchovies, herring, and sardines are the most fished fish in the world, and almost all of the catch is used as fish meal for aquaculture. The assault on protein from the sea only intensifies.
Rates of habitat destruction and of species extinction have led to the ongoing sixth major extinction event in history — and the first one to be caused by human activity. A majority of the world’s most species-rich habitats — such as tropical forests and coral reefs — have been destroyed or are being significantly impacted. In Malaysia, for example, rainforests have been being cut down for decades in order to produce more palm oil and lumber for export.
The extinction rate has increased to 1,000 times faster than before the Industrial Revolution. It is projected to increase another tenfold before the end of this century. Much of the recent extinctions have occurred on the main continents from land-use changes, introduction of invasive species, and climate change. The extinction rate that humans are now causing has not been seen since the Cretaceous–Paleogene extinction event 65 million years ago when an asteroid impact wiped out the dinosaurs.
Indeed, the collective human impact on biodiversity increasingly resembles a slow-motion asteroid impact on the planet. Tragically, biodiversity is not adequately protected because its value is not included in the market signals that guide the economic decisions of producers and consumers and that dictate the overall operation of the economic system.
The same human activities that drive climate change and biodiversity loss also drive pandemic risk through their impacts on the environment. Changes in land use; the expansion and intensification of agriculture; and unsustainable trade, production, and consumption disrupt nature and increase contact between wildlife, livestock, pathogens, and people. There is no mystery behind this recurring and all-to-common path to pandemics.
The majority (70%) of emerging diseases such as AIDS, Ebola, SARS, MERS, bird flu, swine flu, and the novel coronavirus originate in animals. These microbes “spill over” due to contact among wildlife, livestock, and people such as in the messy wildlife markets of exotic animals nestled in the shadows of opulent Chinese skyscrapers.
The novel coronavirus triggered a global economic seizure when many countries had to suddenly shut down their economies in a manner unprecedented in human history. Unless collective human behavior changes, future pandemics will become more frequent, spread more rapidly, do more damage to the world economy, and likely kill more people than COVID-19 (which may well turn out to have caused the greatest economic, political, and social damage to humankind since Word War II). Nature's revenge in the form of tiny invisible microbes?
The current rate of ocean acidification is at least 100 times faster than at any time in the last 20 million years, and surface ocean pH has decreased by about 0.1 units relative to pre-industrial times. The oceans, covering 70 percent of the planet's surface, currently absorb about 25 percent of human-emitted carbon dioxide through dissolution into the seawater and through uptake of carbon by marine organisms.
The portion of this carbon dioxide that turns into carbonic acid has the destabilizing side effect of increasing the acidity (reducing the pH) of surface seawater, making it more corrosive and threatening to normal ecosystem functionality.
Corals, in particular, are sensitive to plunging pH levels and warming waters, and stressed reefs are undergoing negative shifts in dynamics, productivity, and species composition. Marine plankton are also vulnerable to pH reductions. As water acidifies, the small phytoplankton at the very base of the planet's food chains struggle to form carbonate for their skeletal parts. This loss of productivity would severely weaken those vital chains of sustenance — all the way up.
Through severe storms, floods, and droughts; we are viscerally more aware of the destabilizing climate-change effects of the extra heat in the atmosphere resulting from fossil fuel combustion. But over 90 percent of greenhouse-effect trapped heat is, in fact, absorbed by the sea. It has been estimated that, without this massive watery heat sink capacity of the world's oceans, the average air temperature around the globe would already have increased by a staggering 97 degrees Fahrenheit and pushed our planet into a hellish and unlivable permanent hot-house state. The deep sea is now warming about nine times faster that it was in the 1960s, '70s, or '80s.
Record-breaking ocean temperatures from a changing climate have damaged more than two-thirds of the Great Barrier Reef — the largest living structure on Earth. The potent combination of warming + acidifying water has resulted in more and more mass coral reef bleaching events around the globe. Though they only take up a very small area in the world's oceans, coral reefs are home to a quarter of all marine species.
Already half of the world's coral reefs have been lost over the last thirty years. Ocean scientists, in a 2013 report to the United Nations, expressed their worry that by 2050, virtually all of he world's coral reefs could be transformed into dead colorless skeletons.
By the end of the century, we will have dramatically transformed the sea the into an unrecognizable hot, sour, breathless habitat for the few hardy marine species that can somehow manage to eke out an existence under these bleak inhospitable conditions.
More heat in the atmosphere also cranks up the dial on the hydrologic cycle, with rising rates of water storage and circulation in the atmosphere producing drier droughts and wetter floods around the globe. Cyprus and other countries in the eastern Mediterranean, for example, are increasingly vulnerable to drought as the changing climate brings higher temperatures and less precipitation.
These conditions invariably lead to mass migrations of climate refugees inevitably followed by social and political instability from the involuntary anxious clashing of diverse cultures.
Groundwater aquifer depletion from expanding human populations and from competition for water resources is threatening the long-term economic viability of agricultural regions. Food production is artificially inflated by unsustainable drawdown practices of mining for groundwater creating precarious food-bubble economies that would inevitably lead to spiraling global food shortage crises.
Almost all of the world's rivers have been greatly altered, and roughly 25 percent of global river flows no longer reach the ocean due to these river-flow diversions. These dramatic reductions of global freshwater supplies affect not only the biodiversity of river systems, but also the food sources, health, and security of local communities, climate regulation, and carbon sequestration. Tipping points may be reached that ultimately result in the complete collapse of regional hydrologic cycles.
Human activities now convert more nitrogen from the atmosphere into reactive forms — mostly to enhance food production via fertilizers — than all of the Earth’s terrestrial processes combined. The majority of it ends up in waterways and coastal zones. The sudden unintended introduction of very high levels of nutrients into formerly lower nutrient systems — eutrophication — like from human agricultural runoffs of nitrogen and phosphorus, have caused abrupt shifts in lakes and marine ecosystems.
Species of primary producers adapted to the lower nutrient conditions are suddenly outcompeted by faster growing species adapted to the one-time anomalous high-nutrient conditions. The suddenness of the shift only affects the primary producers, resulting in a disorganized and out-of-balance collection of species, which in turn triggers disruptive plankton blooms and mass fish die-offs.
Toxic chemicals are a form of unnatural, human-made pollution that no existing natural systems have experienced before and that no existing natural systems can benefit from in a positive way. Out of some 80,000 chemicals in commerce, 1,000 are known to be neurotoxic. Different chemicals have different pathways through Earth’s biosphere. Some, such as mercury or DDT, can undergo long-range transport via ocean or atmospheric dynamics.
Chronic, low-dose exposure may lead to subtle non-lethal effects that hinder development, disrupt endocrine systems, impede reproduction, or cause mutagenesis. These are usually most visible in top predators and human populations.
Toxic "everywhere chemicals" from plastics, cosmetics, and pesticides are now pervasive in the natural world. With polychlorinated-biphenyls (PCBs), other persistent toxic chemicals such as DDT, and heavy metal compounds continuing to accumulate throughout the world's widely dispersed marine ecosystems, it has become difficult to find a sample of ocean water anywhere not contaminated by some form of chemical pollution.
Tragically, our woeful lack of concern for natural habitat complexity, biodiversity, and equilibrium has allowed for the destructive and destabilizing exploitation of land, forest, and water resources for too long with grossly damaging and unsustainable levels of harvesting and cultivation. And far too little attention has been given to the proper handling and disposal of toxic chemicals.
Our efforts to protect Earth's ecosystems have been sadly lacking in scientific rigor and in a deep understanding of, or concern for, complex and dynamic ecological interrelationships. For the tricky thing about ecology is this: ecosystems are complex networks where everything is connected. EVERYTHING is connected!
From an ecological systems perspective (the only perspective that ultimately matters), human supremacy is an absurdity. Delusional. Stupid.
Indeed, grossly disrupting global ecological balances, as we have been recklessly doing of late, and rolling the dice with risky and unpredictable tipping points and unmanageable runaway negative feedback loops is akin to slowly and unwittingly sawing off the limb on which humanity itself perches.