Man's Influence on Climate. 131 



In all this there can be no question but that man has at least 

 to a considerable extent, the control of the climate in his power. It 

 is, however, not a local matter influenced by the action of any one 

 individual, but a public question, requiring co-operative action, which 

 best takes the form of Government control, on purpose to check the 

 progress of such wide- spread disaster as threatens sooner or later 

 to overtake the whole of Africa, as it has already claimed much of 

 the Karroo in the south and of the Sahara and Ecvpt, Arabia and 

 Persia in the north. 



It may be asked in what way man can improve matters. The 

 destruction is evident and increasing, but what can be done to stop 

 it without interfering with the present utilisation of the land ? The 

 answer is : much, and in many ways. 



The culture of crops supplying winter-feed allows what is 

 considered a summer stock of cattle to be maintained all the year 

 round without inflicting hardship either on the veld or on the stock. 

 The disuse of grass-burning and its substitution by paddocks grazed 

 in rotation, but never injuriously grazed, does much to maintain or 

 improve the climatic condition instead of allowing it to drift, while 

 feeding stock by manure-grown crops upon such paddocks gives them 

 a manurial improvement so long as the grazing is in moderation and 

 beef or wool the only crops removed. 



The popular prejudice in favour of grass-burning is only related 

 to pastoral agriculture, which is now rapidly giving place in most 

 localities to more intensive farming ; and the latter requires the 

 adoption of methods specially fitted for its use, and the abolition 

 of such methods as no longer fit the altered practice. 



The production of abundant foliage, by whatever means, has a 

 tendency in the right direction, so long as the soil is able to main- 

 tain that foliage, and in this respect cultivation plays an important 

 part, but it is more particularly in the enormous extension of planta- 

 tions of moisture-attracting trees that climatic improvement is assured, 

 or at least that some check can be put upon the rapid desiccation 

 now going on. In Europe 25 per cent, of the total area is con- 

 sidered a fair proportion under forest in order to secure suitable 

 climatic conditions. In South Africa, with its higher temperature 

 and lower average rainfall, even a larger proportion is necessary, 

 whereas the actual area under forest of all kinds is much less than 

 one per cent. 



Even much of the existent plantation-forests consist of varieties 

 of doubtful advantage in this respect, their rapid growth causing 

 more moisture to be used than is attracted by them. But even there 

 an advantage is gained in this, that winds dried out by contact with 

 such plantations naturally become warmer and lighter by the loss 

 of their moisture and rise, leaving their places to be filled by further 

 moisture-laden clouds from the sea, and thus a constant pumping 

 arrangement from the sea on to the land is automatically produced ; 

 this also applies to all forests. 



