Nobel laureate and former US vice-president Al Gore made an impassioned plea recently in Washington to all US citizens - particularly political leaders, entrepreneurs, innovators and engineers - to commit to producing electricity only from renewable energy sources. To those who say a complete switch-over to a carbon-free energy grid sounds unachievable in the timeframe he sets, that is 10 years, Gore says it is a challenge that is achievable and affordable, and it has the potential to completely transform our lives. Whether or not such an ambitious target is achievable in full, Gore's timing is perfect: he has thrown down the green gauntlet when people are tuned in to the need for greater energy efficiency, to reduce pollution and maximise cost-benefit in the backdrop of rising fuel costs and falling supplies. Gore's challenge comes when the US is experiencing a fall in demand for fuel, probably one of the reasons for the drop in crude oil prices. It doesn't take much persuasion to convince the converted; yet when a popular green champion like Gore asks people to give the issue priority, he can be sure that his voice will not go unheeded. Curiously, there is no let-up in demand for fuel in India where, traditionally, people tend to err on the side of caution. Facing the climate change and fuel shortfall challenge is something that needs global effort. Economic growth and poverty alleviation are important goals, but the thrust towards using available energy efficiently has so far been inadequate. A lot could be achieved by merely widening roads, for instance, to enable good traffic management that could cut fuel consumption by minimising idling on roads due to jams. Another easily adoptable strategy is to encourage switching over to compact fluorescent lamps that are longer lasting and consume less energy. Gore points out that as the demand for renewable energy grows, cost will continue to fall as it did with silicon - used to make solar cells and computer chips. With economies of scale, energy generated from the sun, wind and water would become more affordable and, eventually, all electricity generated could be from non-fossil fuel sources. All it needs to step up the green revolution in energy is a part-persuasion, part-legislation strategy with strong political leadership and individual faith and determination. Like Gore, Prime Minister Manmohan Singh and opposition leader L K Advani should speak out and present a united front to overcome the difficulties posed by the challenge. By thinking big and green, the 10-year challenge might be met, at least in part.