Guest writer: Kiran Varanasi is a research student in computer science, 26 years old. He was born and brought up in the south of India near the delta region of the Godavari river, and lives currently in Grenoble, in the French Alps. Kiran raises a concern I rarely address, from a perspective I don’t have.
Nowadays, environmentalists have to speak about global warming. The general public is slowly getting aware of the dangers of climate change, though most people appear unaware of both the nature and scale of the problem. As acknowledged by everyone, this is the mother of all problems. Pictures of poor polar bears stranded on floating sheets of ice have become part of our pop-culture. Spinning windmills have become part of political advertising, magically boosting the candidate’s green credentials. Which bottle of wine has lower CO2 emissions? Which feminine products are greener? All these have become important questions to worry about. This funny cartoon is a case in point. Hidden underneath these images however, is the real challenge of green activism: fresh water crisis.
Water conservation and prevention of water pollution were one of the earliest battles of environmentalists – much before climate change was ever heard of. Though they have become the green equivalent of 80s fashion, these battles are as relevant today as it was ever. In fact, fresh water is the most important battle in the war against global warming.
Fresh water is the elixir of life. The entire bio eco-system is based on this. Any minor disturbances on the supply of fresh water will have catastrophic impacts on biodiversity. The scariest effects of climate change are not rising sea levels or massive tornadoes, as exemplified by films such as The Day after Tomorrow. Scary though they might be, there are scarier problems: desertification of rainforests, severe droughts, drying river beds due to melting glaciers. In this post, I would like to write on the complex water cycle, and how sensitive it is to climate disturbances.
The first thing to note is that not all places are equal with respect to the availability of fresh water. This makes fresh water a very “local” problem. For example, the polar ice caps account for 60% of our fresh water reserves. These regions will not be facing any shortage of fresh water anytime soon. But not many life-forms inhabit the polar region to share this joyful information. For most of the life-forms, the news is rather unjoyful.
Spaceship Earth is 12,800 km in diameter, but most life forms are concentrated in very tiny pockets on its surface. The terrestrial biodiversity is mostly concentrated on the thin belt of the region that surrounds the equator. The marine biodiversity, similarly, is restricted to narrow bands of subcontinental shelves. Rising sea water temperatures and increasing acidity of the sea pose serious threats to this marine life. But in this post, I will take a distinctly terrestrial viewpoint and explain the threats to terrestrial life. As it looks from above the ground, the biggest threat to life is depletion of fresh water.
The biggest treasures of biodiversity on earth are to be found in narrow river plains and delta regions – most of them around the equator. These are known as biodiversity hotspots. A quick, but incomplete, list includes the Indonesian rainforest, the Amazonian rain forest, and the great forests of Africa and India. The biggest reasons why life flourished in these pockets of land is abundant fresh water and sunshine. Now, the fresh water part of the equation is under threat. This threat is due to two factors (a) overpopulation of the human species, which denies fresh water to other life forms, and (b) global climate change which makes things even worse. Firstly, let’s discuss
The human animal
The biggest impact of humans happened with the discovery of agriculture. Rainforest was burnt down, and the land was cleared for cultivation. The animals which earlier lived in those regions suffered the loss of niche habitats. Clearly, it was not land that was in short supply, but land with abundant fresh water. Thus, humans began their long journey of monopolization of this scarce resource. Similar to other life forms, humans thrived in regions with abundant fresh water and sunlight. Such regions offer the best avenues for the cultivation of food grains.
For example, India looks like a tiny piece of land, but this country possesses the largest arable land in the world (558,080 sq-km). This is achieved by a criss-crossing network of rivers which are fed by Himalayan glaciers and monsoon rains, making a magical 48% of the surface suitable for cultivation. For this reason, this tiny piece of land has throughout history housed 1/5th of humanity. The same can be said for China (545,960 sq-km). An apt comparison would be with Russia, the largest country in the world, which has just 46,000 sq-km of arable land.
Due to our monopoly of the fresh water resource, we humans have multiplied in large numbers. Further advances in medicine and public health have made the population problem more acute. But what has not changed in the story is this: agriculture continues to be the biggest consumer of fresh water. It is precisely this occupation that is denying fresh water to the other denizens of this planet. Most of the forest covers in India, Europe and North America has long disappeared. In today’s world, the battlefront has moved to the Amazon river basin, African hinterland and the Indonesian rainforest. Painful deforestation happens every passing minute, and the reason is always the same: monopolization of fresh water by agriculture. This agriculture can take several forms – subsistence agriculture to nourish the poorest of the poor (assisted by logging, the source of firewood – their only energy source), soybean farms to grow as cattle-feed, direct cattle rearing ranches, cultivation of palm trees for biodiesel and so on.
As an environmentalist, I deeply support equitable distribution of fresh water to all life forms on this planet. But as a human, I also worry about the availability of fresh water to my own species.
We human beings need 1700 cubic-metres of fresh water per person per year. This caters to our needs for drinking, sanitation, industries, and above all, agriculture—the king of this demand. Any shortage of fresh water will directly hit food production. When we think of a fresh water crisis, we should not think of thirst, but of hunger and famine. Earlier, people used to think of land as the limiting resource for human population growth. In retrospect, this was not correct. The limiting resource is the availability of fresh water: civilizations have tumbled when rivers changed course. Now fresh water is ready to exercise its limiting factors on human numbers once more: India currently houses 1.1 billion people. This huge population, still has more water than is barely sufficient: 1800 cubic-metres of fresh water per person. This miracle is a testimony of how that land is blessed by rivers. But, the population of India is bound to still increase to 1.5 billions, and stabilize at this level at mid-century. This results in an acute 30% shortage of fresh water to its citizens – resulting in water wars (food wars) and destabilization of the region. The same story has its echoes in Africa, middle east, China and so on.
This is good news neither for humans nor other life forms. Humans will always monopolize fresh water. A fresh water crisis means more rainforest will be burnt, more land will be cleared for agriculture. and more plants and animals will go extinct.
Global climate change
Now we move on to the second reason for the fresh water crisis. Climate change makes much worse, everything we have learnt before. Several glaciers (pdf) are already receding rapidly in the light of increasing global temperatures. This will devastate the sources of all the major rivers on this planet. Several rivers are facing immediate prospects of drying up, or significantly lower amounts of water. For example, Ganges in India is bound to go dry part of the year, and this is not one of the changes that we can prevent!
The glacier feeding it is retreating.
Climate change also brings in erratic rainfall patterns, which also destabilize the course of the river. Flooding will increasingly become common, and so will be drying up of rivers.
When a river dries up, it is not a simple fact of less availability of H2O. Rivers bring in alluvium, when they flood the plains. Lacking these deposits, most of the agricultural land in the world will become barren. In fact, the water cycle of each river is a very complicated and non-linear system with several factors at play. A minor disturbance can alter the course of a river, and leave a desert in its wake. Ancient civilizations such as the Indus-valley civilization and the Mesopotamian civilization have tumbled because of these reasons. We discover the artifacts of these great civilizations in what are now desert regions, but what used to be fertile river plains.
And it is not just humans who are affected by this amplification of the fresh water crisis. I grew up in India, where newspapers routinely report deaths of peacocks, pelicans and other birds in the summer season, due to drying up water holes. Wild animals such as deer, bears and leopards are forced to migrate to human inhabited regions due to lack of water in the forests. Mass animal migrations on the African savannah have been sighted recently. As humans have already monopolized the fresh water regions on the planet, these animals have not much place to go.
Melting glaciers and drying up river beds accentuate deforestation. Reduced forest cover means more CO2 and methane in the atmosphere. This is a very important feedback loop for climate change. This is the reason why I have mentioned earlier: the fresh water crisis is the Waterloo battle in the war against climate change.
What can we do?
By this point, I hope you are convinced that ensuring fresh water to every single place on the planet is a noble task for each of us global citizens, wherever we live. We are not protected by geological isolation: the implications of deforestation, desertification, food crisis and biodiversity extinction are too horrible to contemplate.
There is no shortage of fresh water, on this planet, per se. As I mentioned earlier, this problem is a very “local” problem by its nature. Our first task is to redistribute the pangs of the fresh water crisis across the globe, to lessen their impact. This is not as easy as it seems.
The concept of virtual water tells us the demand of fresh water for several types of products: food, clothing, consumer goods etc. Regions which are facing fresh water crisis should reduce the production of food/stuff which are heavily dependent on fresh water, for example, rice, coffee, and meat. We should preferably import these items from other places in the world.
As we observed, agriculture is the most intensive consumer of fresh water. But, rearing livestock is dependent on top of this agriculture for its feed, so it is much worse. A kilogram of beef requires 4100 gallons of fresh water. Reduced consumption of meat will alleviate the pangs of fresh water crisis.
Green water, or underground water resources, should be more expediently used. Rainwater should be explicitly harvested, and used for groundwater recharge.
Geological water acquifiers, or fossil water, should be used in the most careful fashion, for only the most pressing needs.
Distribution of water through canals has to be done expediently. Sealed water pipes should be used wherever possible. No drop of water should be wasted either to sunlight, or to the sea. Drip irrigation should be employed in places with water shortage.
Industrial waste should be monitored so that it does not pollute rivers and waterways. A lot of usable fresh water is lost due to these types of pollution.
Bio-fuels and bio-mass directly compete for fresh water. So it is imperative to have a strong oversight that they are not stealing it from something more valuable: like agriculture, or god forbid, rain forests.
Linking rivers through minor canals might help. These projects should be undertaken, but only after the complex dynamics of the water cycle are thoroughly studied and their environmental impacts are taken into account.
We should encourage better seed varieties which are less dependent on water and produce more yields. Sometimes, this means we should encourage genetically modified seed varieties.
In the end, we might have no option but use intensive water desalination projects. These demand a lot of energy. We should be careful that only renewable or nuclear energy is used in this effort. Solar energy can be particularly useful for desalination, because we are not much bothered by intermittent availability. Fossil fuels should be avoided by all means; they will make the problem only worse due to their amplification of climate change.
[See more in the March 20, 2008 issue of Nature, which covered extensively on the fresh water crisis, and has a wealth of information on the topic]