At the start of each year, many people make New Year resolutions to improve their behaviour. Spurred by appalling images of the harm plastics inflict on marine life, some Singaporeans' resolutions may involve a greater effort at recycling and reducing their reliance on single-use plastics.

However, while a desire to go green is commendable, twinning emotion (outrage, remorse, compassion) with reason and hard facts would likely achieve a better outcome for the environment than sentiments alone. This calls for understanding the costs and benefits of our actions, so we make choices that yield the highest net benefits. To do that, we need to have a better understanding of the environmental problems we face.