recently, a group of Kolkata-based taxi drivers did something quite unusual. They decided to tamper with the fuel in their taxis. They mixed 20 litres of diesel with one litre of mustard oil and ran their taxis on it. For them the doping made perfect economic sense. By default, researchers discovered that it reduced carbon monoxide (co) and sulphur dioxide (so2) emissions by as much as 85 per cent.

And this seemingly eerie act by the entrepreneurial taxi drivers is perfectly in line with the happening world over. Globally, researchers are looking at vege