Sir: Professor Peter Smith's comment (letter, 27 May) on Geoffrey Lean's article on the UN "city summit" highlights the major problem of energy demand created by the growth of cities, but takes too little account of the problem of energy, food and job shortage in rural areas as a cause of that growth. This is seen for example in the depredation of forests through human and cattle population growth in the Northern Punjab and Kashmir watersheds (and related shortage of agricultural land) and the growth of Mirpur, Sialkot and Gujranwala.
Growth of eight per cent per annum of the population of Gujranwala is sustainable and relative stability of rural populations in Northern Punjab is possible partly because of income from labour migration to the Gulf, partly through industrial growth and partly through water resources development. But this has also been made possible through the effective use of credit systems supported by the World Bank family (but also massively by the State Bank), permitting a dramatic development of a small scale owner farmer agricultural system and of irrigation and hydro-power, industrial development and a "sites and services" programme for the labour that comes from the countryside.
The reason why cities grow is that they are a massive boon to society; and because where circumstances prevent this growth deprivation, conflict, human degradation and destruction of the environment occur. The answer is indeed international co-operation, but also to create and sustain the resources needed for the inevitable continued growth of cities, recognising that this means relating city and industrial growth to agricultural and rural development.