Letter from Tay Tse Chuan Eugene, Today Online 30 Mar 10;
EARTH Hour, which came and went on Saturday, is not just about switching our lights off, it's about two key forces at work: The Asymmetry Principle versus the Rebound Effect.
The Asymmetry Principle suggests that when you switch off your lights or appliances during Earth Hour, you save more than just the power needed by that one bulb, as the effects of conserving energy resources are amplified further upstream - due to inefficiencies in fuel production, electricity transmission, and so on.
The Rebound Effect suggests that people might change their behaviour with the introduction of energy-efficiency measures, thus offsetting the actual benefits. In other words, you might reduce energy needed from one source, but use more energy switching to alternatives.
We need to see more of the Asymmetry Principle and less of the Rebound Effect. We need more people to switch off their lights and reduce their energy consumption daily - not just during an annual Earth Hour - to amplify the energy savings at the source.
Meanwhile, people should be mindful not to switch to substitute activities or light sources that consume more energy. We must ensure that our actions do not contribute to the problem we are trying to solve.