Yasser Kamran has raised the very important issue of global warming. Al Gore in his video presentation 'The Inconvenient Truth' tells us that with the melting of a major part of the icecaps at Greenland and Antarctica, sea levels will rise by 20 feet by end of the century, displacing millions of people from coastal and low-lying regions. That means big cities on coastlines, and that includes Karachi, will be submerged in water. Pakistan has a choice between the dirty thermal power, which will add to global warming, and hydel power, which is clean, cheap, and abundant-40,000 megawatts, of which 3600 megawatts can be had in six years time by starting Kalabagh dam now. Other than cheap power, Sindh and Punjab will both also get an additional 2.2 million-acre feet of water for irrigation. It needs to be stressed that the apprehensions of the smaller provinces are based on lack of proper information. It is a duty of the national press to educate the public opinion about this. -KHURSHID ANWER, Lahore, via e-mail, October 30.