Every now and then, the authorities gleefully mention the trillions of tons of coal buried in Thar as the panacea for our power generation problems. This is often done to divert attention from the vast potential of producing clean energy from hydroelectric dams like Kalabagh dam, which has been made controversial by the smaller provinces. The rosy picture of Thar coal is painted without telling the people about the negative side of coal power. China is a prime example of coal-derived energy where 1/3rd of agricultural crops are adversely affected by acid rains that occur due to sulphur belched in the atmosphere by coal-fired plants. Thousands of deaths that are caused in China by coalmining hazards are an added disadvantage. Moreover, the coal plants don't solve the problem of water shortage, which can only be resolved by constructing mega water reservoirs that provide cheap power as an added bonus. Our politicians ought to present pros and cons of national projects. Thar coal is no substitute for a large hydro-electric dam for which Allah has blessed Pakistan with an ideal site at Kalabagh. -DR M. YAQOOB BHATTI, Lahore Cantt., via e-mail, July 5.