Arthu Lloyd’s letter about polluted water (5 October, pg 10) reminded me of a calculation my late brother, a maths teacher, made in 1998:
- The world’s rivers have a flow of 40 000km3 per annum – 10% is polluted.
Total earth’s water:
- Oceans: 1,35 billion km3.
- Ice caps: 28 million km3.
- Groundwater: 8 million km3.
Demand in 1998: 3 500km3.
Population in 1998: 6 billion.
Population 2025: 8,5 billion.
If the population increases as it is doing, clean water fit for human use will run out worldwide in the next 10 years. The earth’s natural systems clean polluted water but the human population is increasing so fast it is overwhelming the cleaning systems.
At the recent Earth Conference in Rio, the one constant on all agendas was overpopulation. It is time that all media worldwide realised the urgency of this subject and campaigned for population control.
