Guyana and the wider world
A number of persons have called me, mainly students I believe, asking for more details about the present threats to the global environment, left in the wake of the relentless pursuit of
Genetic wipe-out
Soil wipe-out
Fresh water wipe-out
by Dr Clive Thomas
Stabroek News
June 24, 2001
globalisation. Most of them have heard of the various doomsday scenarios, or seen movies and documentaries on them. They are curious to learn how serious is the threat of global extinction.
They have been provoked by the references to the "fraying web of life" and the few manifestations of this phenomenon, which I have carried over the past few weeks. This week's contribution will
pull together some of the more dramatic instances of this erosion of the global environment.
Let us start with the source of our food supplies. Crop genetic erosion has reached a stage where researchers now talk of the genetic wipe-out of farmers' varieties and their replacement by
varieties created by the transnational firms (TNCs). It has been estimated that, in the field, crop germplasm is eroding at the alarming rate of 1-2 per cent per year. About one-eighth of the world's flora, or as many as 34,000 species of plants, are facing extinction. The sad part also is that, for every higher-order plant which disappears from earth, 30 other species of insects, fungi and bacteria are carried with it.
Scientists have estimated that between 4,000 - 90,000 species may be dying out annually. This decline in crop genetic diversity has been calculated to be of the order of 2 per cent per year.
Tropical forests, on which we all critically depend, are also disappearing at an annual rate of approximately one per cent. The growth of technology has not compensated for this erosion.
Indeed the switch from farmers' varieties to dependence on TNCs' varieties has been likened to "building the roof with stones from the foundation".
Moving from crops to livestock, we find that an estimated 70 breeds per year or 5 per cent of the earth's livestock diversity, may be eroding each year. Scientists report that as many as
one-third of all domesticated animal breeds are already endangered. Since livestock compete with humans for crop supplies, the problem of crop erosion compounds that of livestock erosion.
As stated last week a significant part of our food comes from irrigated soils. We are very familiar with food cultivation through irrigation in Guyana, as our sugar and rice crops show. Of
the 250 million irrigated hectares worldwide, as much as one-quarter of this has been damaged through the mismanagement of irrigated soils. Thus scientists report that from the Amazon river
alone, which forms part of Guyana's ecosystems, nearly one trillion tonnes of sediment flow into the Atlantic. It is worse elsewhere. The top soil eroded each year by the Huang Ho river in
China is about 10-15 per cent greater (about 1.1 trillion tonnes). And, in the Bay of Bengal, over 3 trillion tonnes are swept away through the Ganges/Brahmaputra river system. On the whole the
earth's soil is being destroyed at a rate 13 times faster than it is being created. The threat of soil wipe-out is real. During the second half of the last century as many as 1.5 billion hectares of
crop land have been eroded. The annual replant cost of the water/nutrients lost in this process, is estimated to be over US$250 million.
The same situation holds true for our water supplies. While we are aware of the abundance of water on earth, it is important to note that less than one per cent (0.5 per cent) of this is neither salted nor ice-encased. Rainfall and ice melt provide the bulk of our flesh water, about 40-50,000 cubic kilometers annually. However, the demand for fresh water is doubling every 20 years. In view of this, it has been projected in some quarters that the earth may face a water crisis. Present trends indicate that our annual need for water could be more than 50 per cent greater than annual supplies. In this scenario absolute water shortages are bound to occur, affecting approximately 2 billion persons, mostly in the developing countries. The stark truth also is that, food cultivation and household consumption will face intense competition for available water supplies.
Turning to the oceans, we find that at least 70 per cent of the world's marine species are endangered. As many as 980 fish species are now threatened. Much of this threat derives from the destruction of the world's coral reefs. It is now projected that 60-70 per cent of the coral reefs could disappear within a generation.
Atmospheric resources wipe-out
As these critical biological resources disappear, pollution from our various activities on earth is simultaneously eroding our atmospheric resources. Climate change and increased exposure to ultraviolet are creating unprecedented challenges on a global scale. Even the non-sensationalist World Bank, has calculated that global warming of a 2-3 degrees centigrade rise in global mean temperatures, would endanger one-third of all surviving forests species, and melt mountain glaciers by one-third to one-half. These in turn would devastate global agriculture.
In the developing regions, global warming would produce serious declines in crop production. In the colder rich countries of the North the outcomes are likely to be erratic, actually improving in some instances and getting worse in others. This fear of global warming has already led to pressures on countries in the South to co-operate in scientific experiments aimed to reverse the Greenhouse effect.
One such proposal is to turn Chile's coastal waters into a carbon sink by putting into it heavy concentrations of nitrogen, which it is hoped would stimulate unnatural levels of biological activities in these waters. Incredulous as it might seem, discussions on this matter have already started with the Chilean government! The enormous risks attached to such planetary experimentation cannot be overstressed. That these risks are being concentrated in the poorer countries of the South, is cause for great concern.
Meanwhile, globalisation marches on relentlessly. The period of globalisation beginning in the 1980s has witnessed the most intensive human exploitation of the earth' s ecosystems in its
history. The linkage between the erosion of our environment or the fraying of the web of life and globalisation is no accident. It is a human-made disaster that was bound to occur, if good sense
does not prevail over private profit at any cost.