Is climate change caused by rich countries only?

| Friday April 13, 2007 00:00

International acknowledgement, now, (even by Bush's America) that humanity bears substantial responsibility for global warming with its various negative impacts on the environment, reminded me of our publication of the paper by Prof Cooke 23 years ago.

 

Fundamental changes have taken place in man's relationship to the land, in Botswana, especially with regard to the keeping of livestock and the utilisation of grazing resources, wrote Prof Cooke. The changes have been associated with three major developments, namely: a huge increase in human and animal numbers; a great increase in the economic value of cattle, and an extension of permanent cattle posts on to the Kalahari sandveld.

 

In 1966 (when the last previous major drought ended), there were 1 237 000 cattle and 550 000 small stock. By 1979, there were 3 500 000 cattle and 1 770 000 small stock. (The numbers may be higher now).

The human population, according to accurate census figures, was, in 1971, 574 000, and in 1981, 936 000. This represented an increase in the population of 63 percent in 10 years, an annual growth rate in excess of 3 percent.

 

The development of a market-oriented economy had given cattle a high market value, which had gone on increasing since the end of the last drought. The negotiation of EEC subsidies raised the price of Botswana beef 60 percent above world market levels from 1971 onwards. Total sales revenue to beef producers had risen from 9.2 million Pula in 1970, to 30.8 million Pula in 1977, for only a 50 percent increase in the number of cattle slaughtered.

 

This remarkable opportunity to exploit the grazing to get rich occurred, moreover, in a decade of above-average rains, making ample grazing available everywhere, wrote the Professor. The rapid increase in cattle numbers had been primarily due to an even further westward penetration of permanent cattle posts, owned by large herd owners, in the fragile ecosystem of the Kalahari sand-veld, together with increasing pressure on the already crowded communal grazing areas of the east, he added.

 

The expansion on to the sand-veld had been made possible by the modern technology of water prospecting and borehole drilling  so that the age-old protection of the Kalahari,  the absence of easily accessible water  has gone forever. It should be emphasised that this movement has been mainly of large herd owners, not of the small herdsmen, who remain crowded in the east together with the 45 percent of the population who own no cattle, the author noted.

 

The severe drought of the 1960s brought the problem of land degradation into stark relief and concentrated both official and private thinking on the problem.  Since then there has been a stream of research and consultancy reports and a succession of symposia and conferences all pointing to land degradation over the long and the short term.

As the Evaluation Report on Livestock Management and Production concluded: Virtually all range studies conducted over the past two decades point unequivocally to spreading conditions of overstocking and degradation of the vegetation.

 

This degradation includes extension of completely bare ground, disappearance of more palatable grass species and their replacement by less desirable plants, which increasingly include woody and thorny shrubs. An expert on land concluded at the time that 'Cattle-keeping on a large scale in the fragile environment of the western Kalahari, especially with present low standards of range management, presents a high risk of more or less irreversible land degradation.'

 

A closely related subject is the effect of progressive land degradation on local climates.

In 1971, a meteorologist, Anderson, pointed to the danger of heat inversion over Botswana which would lead to a decrease in rainfall.

He also noticed a similar rise in mean minimum temperatures at the same recording stations, which he thought might affect plant activity adversely through a rise in night-time soil temperatures.

 

Cooler temperatures over bare ground were thought to be due to the higher reflectivity (albedo) over bare soil than over vegetated surfaces. This thermal depression results in a decrease in the lifting of air necessary for precipitation mechanisms to operate and may result in local climatic deterioration, according to the experts.

 

Another meteorologist, Flohn, referring to this, has developed the thesis that a drastic albedo increase, such as results from the clearing of high-albedo sandy soils, results in a sharp reduction in local rainfall.

As was noted in the continued discussion of this matter in the following week's Mmegi, the 'Botswana Government has shown a clear appreciation of the problems of land degradation and has allowed, indeed has promoted and encouraged, free and uninhibited investigation and comment and has struggled to formulate and carry out meaningful programmes which have as an ultimate objective the halting and reversal of unfavourable environmental trends.'

I will next week continue with the further discussion, which originally bore the title Botswana's environmental struggle in its presentation at that time.