El Nino and its significance
An evening discourse at the Royal Institution, London - 1998-02-06
I well remember the first time when I heard the intimidating strike of 9 o'clock in this lecture theatre. In those days the officers of the Society wore white tie and tails, and as now the humbler participants wore black tie or its female equivalent. In strode the palaeontologist Louis Leakey. He wore an open-necked bush shirt. Gazing at the audience like someone who had stumbled into a penguin rookery, he said:
"Animals! That is all you are. Animals".
We are indeed animals, whether in black tie or bush shirt. Collectively we are threads in an extraordinary tissue of living organisms, which like a thin blanket covers every part of the earth's surface, itself a combination of rock, water and air interacting with, influencing, and being influenced by the life within it. Ed Wilson of Harvard once imagined a journey from the centre of the earth:
"For the first twelve weeks you travel through furnace-hot rock and magma devoid of life. Three minutes to the surface, 500 metres to go, you encounter the first organisms, bacteria feeding on nutrients that have filtered into the deep-water bearing strata. You breach the surface, and for ten seconds glimpse a dazzling burst of life, tens of thousands of species, plants and animals within a horizontal line of sight. Half a minute later almost all are gone. Two hours later only the faintest traces remain, consisting mainly of people in airliners, who are filled in turn with bacteria."
You may wonder what this has to do with the perturbation of oceanic and atmospheric behaviour which carries the name of El Nino. In this lecture I want to bring out the smallness and variable conditions in our living space and the enormous effects which even relatively minor and temporary changes can make in it. I want to look not only at the history and science of the El Nino phenomenon, but also at climate change in general and the vulnerability of all species, including our own, to such change, the more so at a time when human activity is seen to be accelerating it.
All ecosystems are sensitive to changes in external circumstances. The closer they are to the limits of what they can adapt to, the more drastic the overall result will be. El Nino events are limited in space and time. But they constitute a marvellous example of what can happen in the event of rapid change. They contain lessons which we would be wise to learn.
In the last few months El - or rather - the - Nino has entered the currency of household phases like ozone holes, or the greenhouse effect. It is a useful piece of shorthand to explain any apparent aberration of the weather, and has acquired a bad name for itself. As everyone now knows, it is so called because it happens around the time of the festival of Christmas - the Christ child - along the western coast of South America. It signals the arrival every four years or so of warm water from the west which overlies the more frequent upwelling of cool water (first measured by Humboldt in 1802) from the south, and thereby changes weather conditions, first within the region and then in different degrees in other parts of the world. By the following spring the pool of warm water usually disperses, and conditions return to what they were before.
There is little new about the Nino. Living things along the coast must have been aware of it from the earliest times. All societies based on agriculture and water management through irrigation would have had to reckon with. At sea it causes the virtual disappearance or dispersal of many marine organisms which live near the surface in the cool nutrient-rich waters from the Antarctic, with effects reaching up the food chain and beyond. Early written evidence of it in the mid-19th century reflected concern about the periodic decline in the droppings - or quano - from sea birds which had by then become a rich source of fertilizer.
In 1891 the President of the Lima Geographical Society drew attention to the change in the pattern of ocean currents which seemed concurrent with rains in latitudes where rain rarely came. For the desert these were years of abundance. In his own words, the effects that year
"…… were so palpable …. that large dead alligators and trunks of trees were borne down to Pacasmayo from the north and that the whole temperature of that portion of Peru suffered such a change owing to the hot current that bathed the coast".
He also drew attention to the name given by local fishermen to the current. The phrase El Nino soon had a wider currency.
On the other side of the Pacific, periodic changes in weather conditions had also been observed for a long time. But it was the famine caused by the failure of the Indian monsoon in 1877 which prompted serious efforts to establish the physical mechanisms at work. The search included tracing a possible but, as it turned out, illusary connection with sun spots. But droughts in India and northern Australia, and even temperature fluctuations in south eastern Africa, south western Canada and south eastern United States showed some signs of correlation.
It was the mathematician Sir Gilbert Walker who in 1924, after his retirement from the post of Director General of Observatories in India, identified what he described as the Southern Oscillation, or a see-saw like variation of atmospheric pressure at sea level at different points across the Pacific. For example when it was low at Darwin in northern Australia, it was usually high in Tahiti, and vice-versa. From these observations was derived the Southern Oscillation Index which has been elaborated on but is still in use today.
Not until the 1960 was the evidence from the Nino and that of the Southern Oscillation put conclusively together. Based on information derived from the International Geophysical Year of 1957/8 (by happy coincidence a Nino year) Jacob Bjerknes from the University of California, Los Angeles, in papers of 1966/69 and 1972, identified the unitary character of a phenomenon involving large scale ocean-atmosphere interactions across the Pacific. In the trade it is now known as ENSO (or El Nino Southern Oscillation), but the public, often bewildered by the dense cloud of acronyms, usually prefers to stick to the Nino, and I shall do so tonight. From this has been derived the phase La Nina for the more frequent condition. An alternative is El Viejo or old man. Whether such conditions are seen as more female or elderly is a matter of choice.
In one way or another the Nino has probably been sloshing back and forth throughout the Holocene (the 12,000 years or so since the end of the last glacial episode), and possibly for longer still. So far there has been little research into the more distant past, but proxy evidence for it goes back as far as 1524 with consistant irregularity but average fequency of four years and intensive events every ten. Recent work on the oxygen isotopic composition of a particular species of coral from the western Indian ocean over the last 150 years shows a relationship between Nino events and the Indian monsoon. Inter-annual cycles in the coral correlate with Pacific coral and climate records, suggesting a consistent linkage of events across ocean basins in spite of their changing frequency and amplitude
It must also have some relation to the North Atlantic Oscillation, a more mysterious and longer lived phenomenon with effects on weather on both sides of the Atlantic. Hence the complexities are still greater. But all major climatic events effect eachother, and there are no clear boundaries between them. What then is the Nino? Why does it happen? Until recently most commentators have described it as anomalous, irregular or abnormal. Certainly it can vary in character, strength and timing. But closer scrutiny suggests that is forms part of a natural, regular and normal oscillation reaching from the Indian ocean to the eastern Pacific operated by understandable physical mechanisms, and modified in its manifestations and impacts by random elements of a chaotic kind. It is difficult to reduce the complexities of such a phenomenon to a few propositions, but at root the story is simple.
The upper layers of the Pacific Ocean in equatorial latitudes are characterized by an imbalance: the surface waters in the West are warm (29 to 30 degrees C), and those in the East are cool (22 to 24 degrees C). The gradient between the two is maintained by winds that blow from east to west. The warm water in the west is relatively deep, and as it warms the air above it generates intense rainfall. The cool water in the east is the result of upwelling from the south, induced by trade winds that blow surface water towards the warm pool. By contrast it generates relatively little rainfall.
Every three to seven years the regime changes. The trigger is probably increasing and unreleased heat in the warm pool in the west and the air above it. The first sign of change is that the warm winds reverse direction and begin to blow from west to east, thereby pushing warm water eastwards across the Pacific. There it flows over and suppresses the upwelling cool water. This in turn changes the air above it, generating different patterns of rainfall, sea level in the affected areas rises in a long east-west bulge. Large scale waves both ocean and in the atmosphere transmit the changes far beyond equatorial latitudes, and in different way and degrees the atmospheric system - the thin film of air around the world - is affected. The Nino has taken over.
The Nino's predominance rarely lasts for more than a year. With the dispersal of the excess heat in the warm pool in the western Pacific, the engine driving the system loses strength. Waters and winds return to the temperature gradient of warmth in the west and cool in the east. The Nina or Viejo is once more in charge.
Even if the impacts of this see-saw motion, like water moving back and forth in a bath, are not always the same, the main ones are broadly predicable. During a Nino year there are severe droughts in the countries bordering the western Pacific: Indonesia, New Guinea, north east Australia and the Philippines, with weakened summer monsoon rainfall over southern Asia generally, including India. In the countries bordering the eastern Pacific it is the reverse: there is heavy rainfall in northern Peru, Ecuator and Chile with drier spots in Southern Peru and Bolivia. Further away other concurrent changes have been observed. For example north east South America and southern Africa are drier, and east Africa and the southern United States are wetter. There tend to be fewer Atlantic hurricanes, and more Pacific ones. Such events as volcanic eruptions in low latitudes (El Chichon in 1982 and Pinatubo in 1991) could also affect the working out of the Nino phenomenon.
Such perturbations obviously affect the conditions of life in all its aspects. From micro-organisms through plants and insects to fish and mammals, all have to cope with sudden change. For some it is a disaster, with sharp falls in population density; for others it is an opportunity to be exploited while it lasts; but for most it must be an experience with which they are broadley adapted to cope or at least to recover from. I shall come to the impact of the present Nino in more detail, but three general impacts are worth mentioning now.
Off the coast of South America, primary production at the surface, dependent on such inorganic nutrients as nitrate, phosphate and silicate, greatly diminishes, and the food chain is damaged if not broken in some places. Pockets of such fish species as anchovy may survive but the natural predators on them, from birds, and sea lions to humans, find their catches drastically reduced. By contrast populations of scallop and shrimp seem to increase in the warmth, and other warm water fish - for example skipjack tuna - move in. They move out again with the return of the Nina.
Droughts in the Indonesian Archipelago and neighboring countries subject forests and plants to extreme stress, and forest fires, with the destruction of peat as well as mature trees, affect all parts of the food chain. The animals that live in the leaf litter of the forest floor ( insects, reptiles, amphibians) and soon , those in the trees and canopy (birds, and such primates as orang-utans), and those in mountain or savanna, decline sharply in numbers. Obviously the speed of recovery depends on the intensity and distribution of deluge or draught, but renewal, when it begins, may as elsewhere serve eventually to revitalize the whole landscape, even if some of the losers are lost for ever.
A particularly interesting feature of Nino events is change in the distribution of micro-organisms, and thus in the susceptibility of such creatures as ourselves to disease. Floods bring opportunities for the vectors of such diseases as malaria, dengue and yellow fever, encephalitis and schistosomiasis, and for the agents of such diseases as hepatitis, dysentery, typhoid and cholera. Recent research has suggested mechanisms for the well attested spread of cholera in South America during some Nino events. Warm or brackish water sea combines with run off from the land to produce local plankton blooms in which the cholera bacillus flourishes. The bacilli are ingested by copepods of all kinds, and in poor sanitary conditions are soon conveyed to humans. Similar conditions have produced similar results in other parts of the world.
Of recent Nino events, the present one is probably the most serious yet recorded. But the 1982/3 event ran it fairly close. I saw some of it for myself. For nearly everyone it came as a surprise, and we only knew it was happening after it had begun. I had a privileged ride in Britannia from Acapulco to La Paz in Baja California along the western coast of Mexico. No bluer skies or more sparkling seas could have been imagined. But when the Queen later crossed into U.S. waters, she was greeted with torrential rain. President Reagan's helicopter could not land on Britannia and a royal visit was condemned to yellow oil skins throughout. A weaker Nino took place between 1986 and 1987, and a still weaker but prolonged one between 1991 and 1994.
1997 was special. By that time some of the lessons of previous Ninos had been learnt. Comprehensive ocean-atmosphere models were in place. The results of an international Tropical Ocean Global Atmosphere (TOGA) research programme were also available, together with a network of buoys monitoring ocean and atmospheric conditions across the tropical Pacific. Thus an on-coming Nino was confidently predicted from late 1996 onwards.
By the spring of 1997 the sea surface temperature in the eastern Pacific and sub tropical areas to the north had risen, with strong east-blowing winds from the western Pacific adding to the effect, and by last October the sea surface temperature was as high as 5 degrees C above the average. Sub surface temperatures rose even more sharply, and in December it was 9 degrees C above the average. The bulge in the sea levels could even be seen from space. If previous patterns are followed, the warm water should soon begin to disperse, and there are predictions that the opposite - Nina - phenomenon will develop later this year.
The consequences reach far and wide. As always they are affected by other events, and the Nino label on them must be attached with caution. Even so the direct effects are impressive: typically increased rainfall in some areas, equally typical droughts in others, but in all cases pushed to the extreme. Elsewhere through so called tele-connections events have followed familiar paths with a high measure of local variability. Thus the Indian monsoon was weak but sufficient. Central China, south east Asia and west Africa have endured droughts, and southern Africa is having a poor rainy season. There have been deluges in east Africa, the southern parts of the United States, and southern Brazil, northern Argentina and central Chile. Whether the recent devastating ice storms in eastern Canada and the warm wet weather in western Europe are also connected is a matter of debate. Certainly the European weather was predicted by the European Centre for Medium Range Forecasts at Reading as long ago as early December.
As usual ecosystems have been placed under heavy strain. A particularly sad case is what has happened in the Galapagos Islands, that treasure house of evolutionary distinctness. Although on the equator, the islands are usually kept cool and dry by the Humbollt current, and many species found nowhere else are adapted to these special conditions: green algae off shore, marine iguanas, tortoises, and a wide range of birds, including flightless cormorants, Galapagos penguins, finches and blue footed boobies. As on previous occasions, water temperatures have risen, and there has been heavy rainfall. In the past the indigenous species have survived even big population crashes. Now the future is less certain. The introduction by humans of alien organisms, from fire ants, flies, and other insects to rats, cats and goats has compounded the Nino effect, and Galapagos ecology, already under threat, may never be the same again.
The costs of the present Nino to human affairs are virtually immeasurable. In some cases the Nino was the predominant effect; in others it mixed in with other phenomena; in yet others it had a minor role. A good example is the recent forest fires in Indonesia in which land clearance combined with the Nino to cause widespread and lasting destruction of ecosystems. For the 1982/3 Nino efforts were made to assess overall costs: in terms of human life rather than livelihood there were over a thousand deaths; and in financial terms the price was between $8 & $9 billion.
But these figures are no more than guesses. We have only to look at the range of human activity affected: habitats generally, water supplies, fisheries, agriculture (wheat, maize, cocoa, coffee, tea and livestock), forestry, banking, insurance, even the operation of the Panama Canal, and, as we have seen, the character of the micro-organisms which prey upon us.
In such circumstances and in view of the chaotic element in regional impacts, it may be questioned if detailed prediction is really worthwhile. I suppose that we could simply sit back and let it all happen. But Nino risks, like other risks, can be calculated. This time the world had ample notice of what was likely to happen. The risks at the two ends of the geographical see-saw are pretty high. Others further afield, as in Africa, are lower and more chancey. But in most cases warnings could be given and precautions of a kind could be taken.
The UN Food and Agriculture Organization drew attention to the threat to world food supplies as long ago as last September, and commodity markets have reflected the uncertainty. The World Bank also issued early warnings. On 19th December the UN General Assembly adopted a resolution calling for
"An internationally covented and comprehensive strategy towards the integration of the prevention, initigation and rehabitation of the damages caused by the EL nino phenomenon"
Certainly the costs will be high but when the Nino has finally given way to the Nina, I think it will be less important to work out a balance sheet than to assess the value of the warnings given and the precautions taken.
Even if some Ninos are stronger and longer lasting than others, they are no more than temporary manifestations of an instability, and previous conditions with eventually return. They are part of a global climatic system which is itself subject to constant change. I look now at that wider system, and the significance of the Nino within it.
Most climatic change is slow by human standards. Climate seems to have ridden a slow roller coaster for the past 60 million years, before entering a long undulating downward slide towards the ice age world of the last two and a half million years. Within the ice ages there has been a broad rhythm, with over twenty glacial periods interspersed with 10,000 to 15,000 thousand year interglacials like the present. 125,000 years ago there were hippopotamuses in Trafalgar Square. 18,000 years ago tundra in the same place was trodden by mammoth woolly rhinoceros and reindeer. Even in the last relatively stable 10,000 years there have been important wobbles with farmers in Greenland in the 10th century, vineyards in Salisbury plain in the 12th century, and ice fairs on the River Thames in the 17th.
The reasons for these variations large or small, are still not fully understood, but most see a combination of three main factors. There is the impact of changes in the earth's orbital relationship with the sun know as the Milankovitch effect: eccentricity of orbit (100,000 years) tilt (41,000 years) and wobble (21,000 years). Secondly there is the particular arrangement of land and sea produced by the continuing movement of tectonic plates. Last there is the rise and erosion of mountains: for example the rise of the Himalayas seven or eight million years ago may have changed weather patterns by creating deserts, intensifying the monsoon, and possibly helping to cool the earth by drawing carbon dioxide out of the atmosphere through soil weathering.
Until recently it was generally believed that all such change was slow. Now we are less sure. The evidence of cores drilled through several parts of the Greenland ice cap shows a series of cold and warm spells, even within the last 12,000 years, that raised or lowered the average winter temperature in northern Europe by as much as 10 degrees C over the course of as little as a decade.
A primus example is the Younger Dryas event, a cold episode of around 800 years at the end of the last glaciation when a rapid cooling of surface waters led to a southward re-advance of the ice and a return to glacial conditions in western Europe. It may have been triggered by the discharge of large quantities of melt water from a glacial lake in the area of the Great Lakes into the Atlantic through the Gulf of St. Lawrence. More important it was also associated with a sudden change in the pattern of ocean circulation. In the Atlantic, the upper waters of the ocean, warmed in the tropics, flow north eastwards to the vicinity of Greenland where the arctic air cools them, allowing them to sink. This flow is equal to that of one hundred Amazon rivers, and results in an enormous northward transport of heat. The transfer of this heat accounts for the anomalously warm climate enjoyed by Europe. Without the Gulf Stream, winter temperatures in the North Atlantic and its surrounding lands would abruptly fall by 5 or more degrees C. Dublin would acquire the climate of Spitzbergen.
In addition the waters of the North Atlantic are saltier than those in the Pacific. Salt makes the upper layers of the water denser, and as a result they descend and begin a global circulation pattern that draws the warmer surface water from the tropics northwards. This pattern is vulnerable to large injections of fresh water into the North Atlantic. Such shut downs must have happened many times during the oscillations associated with the ice ages. The prime engine of change seems to be in the North Atlantic rather than, in the case of the Nino, in the tropical Pacific.
How long it may have taken for the earth's climatic system to jump from one mode of operation to another is still unclear, current chronometric methods are not sufficiently precise to yield a firm result. But they could certainly have been within a human lifetime, if not within a decade. No wonder that we need to watch the behaviour of ocean currents south of Greenland. No wonder also that we should watch the current build up of Greenhouse gases which could through melting of the Arctic ice cap set in motion another re-organisation of the ocean circulation and the weather patterns which depend upon it. The Nino oscillation is a matter of months. A major oscillation could be a matter of decades, centuries, or thousands of years.
There is now a new factor at work. Environmental change is accelerating because the human foot is on the accelerator. A periodical visitor from outer space would find more change in the surface of the earth in the last 20 years than he would have found in the last 200, and in the last 200 more than in the last 12,000. There are five main aspects.
Like any other animal species on a bonanza, the human species has multiplied its numbers at a giddy-making rate. There were perhaps around 10 million of us around the end of the last ice age. The introduction of agriculture, the specialization of human function and the growth of cities caused rapid proliferation. By the time of Thomas Malthus when the industrial revolution had barely started, our numbers stood at around one billion. By 1930 they had risen to two billion. There are now almost 6 billion, and by 2025, short of some catastrophe, there will be 8.5 billion. At present there are around 90 million new humans every year. Since the Rio Conference on Environment and Development in 1992, 450 million new people (more than the whole world population at the time of the Roman Empire) have come to inhabit the earth.
Partly as a result in this dizzy increase in our numbers, we have done lasting damage to the earth's green covering. The 1993/4 UN Environmental Data Report show that 17% of the world's soils had been damaged to a greater or lesser extent since 1945. Over the last century the effects of industrialization have become a global rather than a local problem. Even within the enormous land mass of the former Soviet Union, some 16% was judged an ecological disaster by the National Academy of Sciences in 1995. Waste disposal may soon become a bigger problem than consumption of resources. No part of the world is exempt from the waste produced by human activity.
We have polluted both salt and fresh water. The oceans may seem vast, but a sea lion which has never seen a human being will probably carry human made chemicals in his blubber. Coastal areas are particularly at risk from the toxic materials brought down by rivers to the sea. There is widespread pollution of rivers and underground aquifers. At the same time demand for fresh water has doubled every 21 years while supply is the same as it has been for thousands of years.
We have depleted the diversity of life. Mass extinctions have occurred before in the history of life, most famously at the end of the cretacious period 65 million years ago when the long dominance of the dinosaurs came to an end. What is happening today is comparable. Current rates of extinction could be up to one thousand times what they would be under natural conditions. It is a crisis with two aspects: mass extinctions and their habitats, and gross depletion of genetic variability within given species as a large proportion of a population is wiped out. When the archaeologists of the future look at the deposits of the last quarter millennium, they will find a biological discontinuity as big as any in the past. They will expose a richness not of fossils but of plastic bags, discarded products, and if they are unlucky radio active waste.
Finally there are the changes we have brought about in the chemistry of the atmosphere. Acid precipitation is a problem for those down wind of industry, but it is manageable if the political will is there to solve it. Depletion of the stratospheric ozone layer is more serious. Damage to the human metabolism may seem alarming to us, but a more fundamental problem could be the effects on other organisms, including phytoplankton at the base of the food chain.
Then there is climate. Since the industrial revolution, we have been using the sky as a waste unit by enhancing the natural greenhouse effect with emissions of carbon dioxide, methane, nitrous oxide, chlorofluorocarbons and related molecules into the atmosphere. Apart from water vapour, carbon dioxide accounts for the largest proportion of greenhouse gases, and we know from the ice cores that during the last ice age its concentration in the atmosphere was on average between 180 and 210 parts per million. The interglacial average was 280 parts per million, the level before the beginning of the industrial revolution. It is now over 360 parts per million and rising.
There has been controversy about the effects of this rise, but more about the degree of change than about change itself. In its most recent assessment, the Intergovernmental Panel on Climate Change suggested rises in average global temperature of between 1 degree C and 3.5 degrees C by the end of the next century ( an average rate of warming greater than any in the last 10,000 years ) and an average rise in sea level of up to half a metre in the same period, a rate 3 to 6 times faster than that of the last one hundred years. It concluded that
"……the balance of evidence suggests a discernible human influence on global climate".
Although confidence in the modelling has increased, there remain many uncertainties which make it difficult to quantify the risks involved, or the regions most likely to be affected. But in general terms there is likely to be more precipitation, and more extreme and irregular rainfall, particularly in areas subject to the monsoon. Areas that are already wet are likely to get wetter, and arid regions may see more prolonged and severe droughts. Whatever the human contribution to global climate change, the world is at present becoming warmer, and 1997 was the warmest year on record. The figures speak for themselves.
Inevitably there have been suggestions that the frequency and intensity of Nino events maybe linked to global warming. There has been work on the subject at the National Center for Atmospheric Research in Boulder, Colorado, and at the CSIRO in Australia. The evidence is inconclusive. But the Boulder team concluded that:
"….that both the recent trend for more ENSO events since 1976 and the prolonged 1990-95 ENSO event are unexpected given the previous record, with a probability of occurrence of about once of 2,000 years. This opens up the possibility that the ENSO changes may be partly caused by the observed increase in greenhouse gases".
Even the possibility is significant. It reminds us of the numberless interconnections which characterize the world's climate system. The point was well made recently by Professor Fairbanks of the Lamont-Doherty Earth Observatory at Columbia University in New York (and quoted in a perceptive article by Richard Lloyd-Parry in the Independent on Sunday 7 December:
"….The best analogy is to the cogs in a watch, all different sizes, turning at different speeds, some of them directly connected, others not. People are distracted by the predictions of gentle, long term global warming, a few degrees spread over centuries. But small perturbations in the climate can lead to large consequences, and they do not necessarily have to be gradual changes".
As I remarked at the beginning, we are all animals, adapted like the ecosystems of which we are part to relatively stable living conditions. Changes in those conditions whether abrupt or gradual require changes in us. One response is to move to where conditions, whether warmer or cooler, are more congenial. When there were fewer people in the world, that was always an option. But with the steep rise in human population and the other trends I have described, that option is no longer open to us. One of the forecasts for the next century is a strong increase in the number of refugees and of the pathogens which they bring with them, anyway generated by changing conditions of temperature and moisture.
Looking back into the past we should not forget that of the thirty or more urban societies which have ever existed none but our own has survived. The reasons may be various. Population pressure, degradation of the resource base in all its aspects, and environmental change, whatever natural or human-induced, all played a part. For a society living at its ecological limits, any change is perilous, and represents a challenge which most cannot meet. The Nino is a not - so - gentle reminder of our vulnerability. It should make us look again at the actions we are taking, most of them unwitting, which cumulatively and in ways beyond our current knowledge are changing the life system on the surface of the planet, and increasingour own vulnerability within it.
I sometimes wonder what would happen if we, like nearly all species that have ever lived, were simply to be eliminated. Consider a major asteroid impact. If we perished more or less together - say over five years than 50 million years - what would become of the earth? How long would it take for the injury to heal, or for cities to fall apart, for the earth to regenerate, for the animals and plants we have chosen for ourselves to find themselves a more normal place in nature, for the waters and seas to become clean, for the chemistry of the air to return to what it was before we disturbed it? Ninos and Ninas would come and go, the ice would stretch back and forth from the poles, and life would adapt or transform itself as it has for more that 3.5 billion years. Whatever may happen, we are no more than a tiny if precious episode in this mist procession. Let us cherish it while we can.
