Editor, RE: “Africa smallholder farmers among the most affected by climate change” (The New Times, November 22). The problem is the combination of overpopulation and industrialisation. This causes global warming and climate change. Of course overpopulation causes some further problems: air and water pollution, deforestation, mass extinction of animal species, rising food prices and lack of food, mass migrations, increased emergence of new epidemics and pandemics, elevated crime rate, and so on. Some countries in Asia and Africa have already recognised this problem. They try to solve it with family planning, laws or financial incentive. Unfortunately, not always with success. The world population is still growing. Scientists say that rainfall will decline over subtropical land. Bolivia is also already affected by climate change. If we could reduce the growing rate of world population, this would certainly solve all the cited problems. John Doe