This may seem like a surprising statement, but the world's supply of fresh water is finite. As global population rises, the demand for food – and the water that produces it – grows inexorably. Globally, farming accounts for 70 per cent of our withdrawals from this fixed "bank account", this in the face of ever-greater domestic and industrial usage.
Water tables are falling in many parts of the world. Himalayan glaciers will shrink massively in the next century, reducing natural water storage in the mountains. The shortfalls will have to come from groundwater and surface storage. Many great rivers have drastically diminished flows.
Bangladesh is suffering from the diversion of Ganges River water and increased salinisation. Underground aquifers in many places are shrinking so rapidly that NASA satellites are detecting changes in the Earth's gravity. The Water Resources Group has estimated that India may face a 50 per cent lag in water availability relative to demand by 2030 and that global availability may lag demand by as much as 40 per cent; the statistics have been questioned. Sixty years ago, the world's population was about 1.25 billion people; few people, even in arid lands, worried about water supplies. Then came the Green Revolution, with its new, high-yielding crops, which depend on fertilisers and a great deal more irrigated farming. Global populations skyrocketed to nearly seven billion by 2009, with a projected nine billion by 2050. By the same year, the five hundred million people living in areas chronically short of water in the year 2000 will have grown by 45 per cent to four billion. A billion of us currently go hungry because there is not enough water to grow food. Much of the world's water is still unpriced, but it is now the most valuable commodity in the world. To compound the problem, 60 per cent of the world's people live in crowded river basins shared by several countries, often with daggers drawn.
The problems are acute, especially in arid areas with growing populations, where boreholes and aquifers are thought to be the answer. Seemingly a miraculous solution, but not if the drawdown exceeds the replenishment rate, as is the case with the ground water beneath a now-sinking Mexico City's 20 million inhabitants and with Bangkok, Buenos Aires and Jakarta, where pollution and rising salt levels combine with overdrafting.
In China, deep groundwater levels have dropped as much as 295ft (90m) in places. We have perforated the Earth's surface with boreholes to deplete a resource that we all, ultimately, hold in common. Now we stand at the threshold of what I call a third stage in our relationship with water; one where, apparently, cataclysm looms on every side. Vivid Doomsday scenarios espoused by numerous writers have Phoenix imploding as its water supplies fail, the Nile drying up, tens of thousands of people crossing national boundaries to find water.
Futurist after futurist warns that water wars are a certainty in coming centuries. Alas, at least some of these cataclysms could descend upon us if we persist in denying the seriousness of the water crisis and deluding ourselves into thinking that uncontrolled growth and more dams are the solution. They are not.
Yes, there will be shortfalls, people will go thirsty and die, but in the end, as has happened so many times in the past, human ingenuity, quite apart from technology, will find solutions. And in the process, we will develop new, much more respectful relationships with water, even if they do not necessarily have the profound spiritual intertwinings of earlier times.
In the short term, there are four potential ways of improving the situation, but none of them will solve the problem of chronic overdrawing. One lies in spending large sums on systematic improvements to storage and delivery, to the infrastructure behind water supplies. Underground reservoirs have potential. So do simple things like replacing leaking pipes, lining earth-bottomed canals and irrigating plants at their roots with just the right amount of water, among many others. A second solution also makes sense: make farming less thirsty, by using drought-resistant, higher-yielding, even genetically-modified crops. This is much easier said than done, for significant technological breakthroughs lie a long way in the future. Also, we should not forget that planting more crops means more use of water, since each plant transpires vapour into the atmosphere through photosynthesis. One possible solution may lie in developing plants that can grow using saline water but, again, this development is in the future. Then there's another seemingly attractive option: desalinisation. Surprisingly, this has been around a long time. Aristotle remarked that "salt water, when it turns to steam, becomes sweet and the steam does not form salt water when it condenses". Julius Caesar's legions drank fresh water condensed from sea water during his siege of Alexandria in 48-47 BCE. As self-appointed visionaries keep reminding us, desalinisation seems like the answer to all our problems but, in spite of improvements in efficiency, there remain significant environmental and technical problems. Desalinisation, which involves creating and recondensing steam, consumes prodigious amounts of energy, even in its most efficient iterations, so it is currently confined to nations where oil is cheap and abundant.
Nearly half the existing desalinisation plants are in the Arabian Peninsula and along the Persian Gulf, especially in Saudi Arabia and the Gulf states. In most other places, the cost of desalinisation is three or four times that of conventional water sources.
The cost of oil is rising, so the alternatives are either coal or nuclear power, both of which have their own environmental consequences and political baggage. Desalinisation plants operate along sea coasts; many of the most water-hungry areas are far inland, thereby adding huge transport costs to the already high price of a gallon of desalinised water. What, also, are we to do with the brine resulting from desalinisation, which has to be disposed of? Once again, breakthroughs lie in the long-term future. At present, desalinisation is no panacea, for it contributes only about 0.4 per cent of global water supplies.
Finally, there's conservation, which involves both profound changes in our mindsets and completely new attitudes toward water as a marketable commodity. Water is scarce, but it is also a complicated thing to market. It is difficult to move, hard to measure accurately in large quantities and complex to price and charge for. Most people resent paying for water, for they think it should be free or very cheap. Even in dry parts of the world where every drop is precious, the price of water seldom reflects its true scarcity. However, we are entering an era of potentially ferocious trading in water rights and a time when water could cost more than oil, as managing demand becomes an international priority. It's no coincidence that privately owned companies are quietly and aggressively purchasing water rights in many countries. Increasingly, municipal and other authorities are pricing water according to usage. Judging from experience in Australia, Los Angeles and other water markets, the strategy leads to reduced water use, especially when combined with measures to save water, such as reduced-flow toilets and strict timetables for watering. Like oil, water is a commodity that will be the subject of market forces, with price mechanisms that will bring supply and demand into balance. Once water is priced properly, the economics of international trade may encourage water-rich countries to produce water-intensive goods and arid ones to make those that are water-light. Mindsets are notoriously difficult to change, especially in societies accustomed to abundance and seemingly unlimited water supplies.
Using the forces of the marketplace and stricter allocations will not be strategies of first choice, especially in urban settings with high levels of poverty. Nor will conservation in the form of another commonly proposed measure, yet more dam construction, prove effective. History from the near and remote past tells us that dams are no panacea, for they silt up and silt has to be removed or the dam becomes shallower and ever less useful. And, even more important, where is the water to fill them going to come from? No dam ever creates water; it merely captures what is a finite supply. How can new dams provide more water in the era of prolonged global drought that lies ahead? Besides, there's adequate dam capacity in the American West to store any water that will come from the smaller snowpacks of future decades. Short of creating more water, more efficient allocation, extensive water recycling for landscaping and other purposes, drastic reductions in agribusiness water subsidies and miserly use of current supplies are some viable strategies for the future. And this kind of conservation, on scales small and large, is the responsibility of us all. Our survival depends upon it. We have much to learn about water conservation from the experience of our ancestors. Humans have managed water successfully for thousands of years in ways that are often far from the historical radar screen. We learn from their experiences that it is the simple and ingenious that often works best – local water schemes, decisions about sharing and management made by kin, family and small communities. These experiences also teach us that self-sustainability is attainable.
Such ingenuity comes in many forms. It may be a simple idea in the field or, in this day and age, more likely the inspiration for a social and political initiative that changes the way people think. We are moving into an entirely new water future, where equity of use, sustainability to protect future generations and affordability for everyone are major components.
A new paradigm for water management, based on well-defined priorities in which all stakeholders have a voice, will have to govern our future water use. Our salvation lies in long-term thinking, indecisive political leadership and in a reordering of financial priorities for, after all, investing heavily in water management will alleviate much disease and poverty automatically. Above all, the future will need a shift in our relationship with water to one that equates, at least approximately, with that of those who went before us – characterised by a studied caring and reverence.
Elixir: A Human History of Water by Brian Fagan is published by Bloomsbury (£20). To order a copy for the special price of £17 (free P&P) call Independent Books Direct on 08430 600 030.
Saturday, July 2, 2011
Oceans on brink of catastrophe
Marine life facing mass extinction 'within one human generation' / State of seas 'much worse than we thought', says global panel of scientists
The world's oceans are faced with an unprecedented loss of species comparable to the great mass extinctions of prehistory, a major report suggests today. The seas are degenerating far faster than anyone has predicted, the report says, because of the cumulative impact of a number of severe individual stresses, ranging from climate warming and sea-water acidification, to widespread chemical pollution and gross overfishing.
The coming together of these factors is now threatening the marine environment with a catastrophe "unprecedented in human history", according to the report, from a panel of leading marine scientists brought together in Oxford earlier this year by the International Programme on the State of the Ocean (IPSO) and the International Union for the Conservation of Nature (IUCN).
The stark suggestion made by the panel is that the potential extinction of species, from large fish at one end of the scale to tiny corals at the other, is directly comparable to the five great mass extinctions in the geological record, during each of which much of the world's life died out. They range from the Ordovician-Silurian "event" of 450 million years ago, to the Cretaceous-Tertiary extinction of 65 million years ago, which is believed to have wiped out the dinosaurs. The worst of them, the event at the end of the Permian period, 251 million years ago, is thought to have eliminated 70 per cent of species on land and 96 per cent of all species in the sea.
The panel of 27 scientists, who considered the latest research from all areas of marine science, concluded that a "combination of stressors is creating the conditions associated with every previous major extinction of species in Earth's history". They also concluded:
* The speed and rate of degeneration of the oceans is far faster than anyone has predicted;
* Many of the negative impacts identified are greater than the worst predictions;
* The first steps to globally significant extinction may have already begun.
"The findings are shocking," said Dr Alex Rogers, professor of conservation biology at Oxford University and IPSO's scientific director. "As we considered the cumulative effect of what humankind does to the oceans, the implications became far worse than we had individually realised.
"This is a very serious situation demanding unequivocal action at every level. We are looking at consequences for humankind that will impact in our lifetime, and worse, in the lifetime of our children and generations beyond that." Reviewing recent research, the panel of experts "found firm evidence" that the effects of climate change, coupled with other human-induced impacts such as overfishing and nutrient run-off from farming, have already caused a dramatic decline in ocean health.
Not only are there severe declines in many fish species, to the point of commercial extinction in some cases, and an "unparalleled" rate of regional extinction of some habitat types, such as mangrove and seagrass meadows, but some whole marine ecosystems, such as coral reefs, may be gone within a generation.
The report says: "Increasing hypoxia [low oxygen levels] and anoxia [absence of oxygen, known as ocean dead zones], combined with warming of the ocean and acidification, are the three factors which have been present in every mass extinction event in Earth's history.
"There is strong scientific evidence that these three factors are combining in the ocean again, exacerbated by multiple severe stressors. The scientific panel concluded that a new extinction event was inevitable if the current trajectory of damage continues."
The panel pointed to a number of indicators showing how serious the situation is. It said, for example, that a single mass coral bleaching event in 1998 killed 16 per cent of all the world's coral reefs, and pointed out that overfishing has reduced some commercial fish stocks and populations of "bycatch" (unintentionally caught) species by more than 90 per cent.
It disclosed that new scientific research suggests that pollutants, including flame-retardant chemicals and synthetic musks found in detergents, are being traced in the polar seas, and that these chemicals can be absorbed by tiny plastic particles in the ocean which are in turn ingested by marine creatures such as bottom-feeding fish.
Plastic particles also assist the transport of algae from place to place, increasing the occurrence of toxic algal blooms – which are also caused by the influx of nutrient-rich pollution from agricultural land.
The experts agreed that when these and other threats are added together, the ocean and the ecosystems within it are unable to recover, being constantly bombarded with multiple attacks.
The report sets out a series of recommendations and calls on states, regional bodies and the United Nations to enact measures that would better conserve ocean ecosystems, and in particular demands the urgent adoption of better governance of the largely unprotected high seas.
"The world's leading experts on oceans are surprised by the rate and magnitude of changes we are seeing," said Dan Laffoley, the IUCN's senior adviser on marine science and conservation. "The challenges for the future of the ocean are vast, but, unlike previous generations, we know now what needs to happen. The time to protect the blue heart of our planet is now, today and urgent."
The report's conclusions will be presented at the UN in New York this week, when delegates begin discussions on reforming governance of the oceans.
The five great extinctions
The Cretaceous–Tertiary extinction (the End Cretaceous or K-T extinction) 65.5 Mya (million years ago)
Plankton, which lies at the bottom of the ocean food chain took a hard hit in an event that also saw the demise of the last of the non-avian dinosaurs. The giant mosasaurs and plesiosaurs also vacated the seas. An asteroid or volcano eruptions are thought to be to blame.
The Triassic–Jurassic extinction (End Triassic) – 205 Mya
Having a profound affect on sea and land, this period saw 20 per cent of all marine families disappear. In total, half the species known to be living on Earth at that time went extinct. Gradual climate change, fluctuating sea-levels and volcanic eruptions are among the reasons cited for the disappearing species.
The Permian–Triassic extinction (End Permian) 251 Mya
A period known as the "great dying" was the most severe of the earth's extinction events, when 96 per cent of marine species were lost, as well as almost three-quarters of terrestrial species. The planet took a long time to recover from what has also been called "the mother of all mass extinctions".
The late Devonian extinction 360–375 Mya
Three-quarters of all species on Earth died out in a period that may have spanned several million years. The shallow seas were the worst affected and reefs would not recover for another 100 million years. Changes in sea level and climate change were among the suspected causes.
The Ordovician–Silurian extinction (End Ordovician or O-S) – 440–450 Mya
The third largest extinction in Earth's history had two peak dying times. During the Ordovician, most life was in the sea, so it was sea creatures such as trilobites, brachiopods and graptolites that were drastically reduced. In all, some 85 per cent of sea species were wiped out.
Waves of destruction
Case Study One in the panel's report assesses the "deadly trio" of factors – global warming, ocean acidification and anoxia (absence of oxygen). Most if not all of the five global mass extinctions in prehistory carry the fingerprints of these "carbon perturbations", the report says, and the "deadly trio" are present in the ocean today.
Case Study Two looks at coral reefs, and the fact that these "rainforests of the sea" (so-called for their species richness) are now facing multiple threats. The panel concluded that these threats acting together (pollution, acidification, warming, overfishing) will have a greater impact than if they were occurring on their own, and so estimates of how coral reefs will respond to global warming will have to be revised.
Case Study Three examines pollution, which is an old problem, but may be presenting new threats, as a wide range of novel chemicals is now being found in marine ecosystems, from pharmaceuticals to flame retardants, and some are known to be endocrine disrupters or can damage immune systems. Marine litter, especially, plastics, is a huge concern.
Case Study Four looks at over-fishing: it focuses on the Chinese bahaba, a giant fish which was first described by scientists only in the 1930s, but is now critically endangered: it has gone from discovery to near-disappearance in less than 70 years. A recent study showed that 63 per cent of the assessed fish stocks worldwide are over-exploited or depleted.
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