Homo sapiens ~ the species sapiens (wise) of the genus Homo (man) ~ has existed for less than one ten-thousandth of the Earth’s lifespan ~ and, indeed, for less than one-thousandth of the time since animal life ventured from oceans into dry land. It refers to modern humans, in fact, the name itself means ‘Man the Wise’.

In the words of Yuval Noah Harari, a historian, philosopher, and the bestselling author of Sapiens, “About 70,000 years ago, organisms belonging to the species Homo sapiens started to form even more elaborate structures called cultures.

The subsequent development of these cultures is called history. Three important revolutions shaped the course of history: the Cognitive Revolution kick-started history about 70,000 years ago. The Agricultural Revolution, which sped it up about 12,000 years ago.

The Scientific Revolution, which got under way 500 years ago, may well end history and start something completely different.” But humans are not endowed with any special immunity against the usual fate of biological species on Earth: extinction. Indeed, it is now becoming conceivable that within several generations, the human species may face threats to its survival because of its disruption of Earth’s life-supporting ecosystems.

Generally, we call other species ‘endangered’ when their population numbers fall below a critical level. Yet human are assuredly not falling! Not a human habitat shirking. Rather, we are commandeering more and more of the world’s surface area and incoming solar energy for our own needs, and are now using (or pre-empting) earth’s most basic resources 1.8 times faster than our planet’s bio-capacity can regenerate.

That’s equivalent to using the resources of 1.8 Earths. We have allowed ourselves to be entertained by three kinds of illusions: First, there was the illusion of an inexhaustible supply of cheap fuels and raw materials; second, there was the illusion of an almost equally inexhaustible supply of workers willing to do boring, repetitive, and soul-destroying work for very modest rewards, and third, there was the illusion that science and technology would soon, very soon indeed, make everyone so rich that no problem would remain except what to do with our leisure and wealth.

Since it would be too strenuous and perhaps too upsetting to think of and evolve something new, a new life-style for instance, we prefer to indulge in that great and re-assuring psychological exercise which has aptly been called ‘the refusal of consciousness’.

But the most revered exhibit was the Second Law of Thermodynamics, or the Law of Entropy, which asserts that everything always ‘run down’ (unless it is feeding parasitically on something else) and that the Universe must inevitably end in death and dissolution. Survival will depend on our ability to overcome the ‘refusal of consciousness’ which defends totally outdated philosophies of ‘economic progress’ and ‘scientific truth’. History teaches us that societies have long been at war with the environment, treating nature as little more than a resource to be tapped and as a sink into which wastes are dumped. The emerging risks to the human population do not arise from local environmental contamination with direct-acting toxic chemicals, nor from a Malthusians outstripping of Earth’s available material resources. Rather the risk arises from the disruption of natural systems because we are exceeding the biosphere’s carrying capacity ~ i.e. we are overloading the planet’s ‘metabolic’ capacity to absorb, replenish and restore.

Through our aggregate impact, various natural balances are tipping in directions that, if sustained, would make the world less able to support life. Presently, human society has reached a critical threshold in relation to its environment.

The destruction of planet, in the sense of making it unusable for human purposes, has grown to such an extent that it now threatens the continuation of much of nature, as well as the survival and development of society itself. The litany of ecological complaints plaguing the world today encompass urgent problems.

These include: overpopulation, destruction of the ozone layer, global warming, extinction of species, loss of genetic diversity, acid rain, nuclear contamination, tropical deforestation, the elimination of climax forests, wetland destruction, soil erosion, desertification, floods, famines, the despoliation of lakes, streams, and rivers, the drawing down and contamination of ground water, the pollution of coastal waters and estuaries, the destruction of coral reefs, overfishing, expanding landfills, toxic wastes, the poisonous effects of pesticides and herbicides, urban congestion, and the depletion of non-renewable resources.

However, in the words of John Powles: “These effects are intrinsically difficult to predict and to counter, but this is now the main challenge facing those concerned with the health of human populations.” Compared with the huntergatherers era, which predominated until a short 10,000 years ago, human numbers have multiplied one thousand-fold (including a massive ten-fold increase in the past 250 years) and average daily per capita energy use is also about one-thousand times greater.

Indeed, our aggregate impact upon the biosphere is therefore about one million times greater than in those pre-agrarian days. As a result, we are overloading Earth’s capacity to absorb otherwise non-toxic gases, to replenish slowly–renewable resources such as soil and groundwater, and to sustain genetic and ecological diversity.

It is these disruptions that comprise an unprecedented threat to our life-support systems. Ilya Prigogine, a Belgian physical chemist, was awarded the 1977 Nobel Prize in chemistry for his discovery of a major corollary to the Second Law of Thermodynamics. Entropy, according to the Second Law, causes all isolated physical systems to break down over time and is responsible for irreversibility in nature.

For a simple example of entropy, let us consider a smoke ring: it begins as a coherent donut with clearly defined boundaries. But as the molecules separate from one another and dissipate energy into the air, the ring falls apart and disappears.

All socalled closed systems are subject to the same basic process of dissolution; in some, entropy operates quickly, while in others the process takes more time. Prigogine’s discovery was that an open system ~ that is, a system that imports flows of energy from outside the system into it, and out again ~ not only breaks down, but as the flow of energy continues, the system reorganises itself as a higher level of complexity. In a sense, the phenomenon described by Prigogine is the opposite of entropy.

What it means is that complex new forms can emerge spontaneously through self-organisation. The Earth itself, when viewed as a whole, is indeed an open system.

It imports energy from the sun that flows into and the through the elaborate patterns of energy transfer that makes up the earth system, including the oceans, the atmosphere, the various geological processes ~ and life itself. The energy then flows from the Earth back into the universe surrounding it as heat energy in the form of infrared radiation.

But by injecting waste products from their combustion into the atmosphere, we are breaking down the stable climate pattern that has persisted since long ago after the end of the last Ice Age ten millennia ago.

This was not long before the first cities and the beginning of the Agricultural Revolution, which began to spread in the valleys of the Nile, Tigris, Euphrates, Indus and Yellow rivers 8,000 years ago after Stone Age women and men patiently picked and selectively bred plant varieties on which our modern diets still depend. In the process, we are forcing the emergence of a new climate pattern very different from the one to which our entire civilisation is tightly configured and within which we have thrived.

Though Prigogine’s discovery of this new law of nature may seem arcane, its implications for the way we should think about the future are profound. The crushing disappointments that are so often part of the human condition have sometimes led to crises of confidence in the future, replacing hope with ‘unyielding despair’.

But most have learned from their life experiences and the stories told by their elders: what we do in the present, when informed by the knowledge of the past, can shape the future in objectively better ways.

The feeling that we have reached a decisive moment in our history, that we have to make a choice that will determine the course of events for centuries, is not peculiar to our times. Man’s memory makes him aware of the age of his race so that now as two thousand years ago or four thousand years ago he feels that he is living in a terminal period.

But formerly when civilisations were destroyed in one or more continents, in other regions they survived and the accumulated knowledge of the past enabled our brethren to save the future of the race.

The contemporary situation is pregnant with great possibilities, immense dangers or immeasurable rewards. The contemporary mind is vacillating between vague apocalyptic fears and deep mystical yearnings. In reconciling the difference between what ‘is’ and what ‘ought to be’, we are faced with an existential conundrum.

Though we have great difficulty in conceiving of geological time, we have nevertheless become a geologic force; though we cannot imagine evolutionary timescales, we are nevertheless becoming the chief force behind evolution.

The invention of powerful new tools and the development of potent new insights ~ and the discovery of rich, new continents ~ led to exciting new ways of seeing the world and expansive optimism about the future. In the words of E F Schumacher: “Those who realise that in economics as well as in science we have come to the end of an era, have no cause for ‘unyielding despair’.

As the old dispensation dies away, the new one is already prepared. But it will take a lot of honest work to realise the possibilities which are now opening up.”

(The writer is a retired IAS officer)