In an unusual reversal of roles, a global industry - shipping - is pressing international regulators for tighter controls over its toxic emissions. And Hong Kong owners have been in the vanguard, campaigning for earlier use of cleaner fuels by the world's 60,000 ocean-going merchant ships.
The International Maritime Organisation (IMO) stunned itself and the world in April when its normally fractious members agreed to tighten emission caps by 2020 for sulfur oxides (SOx), nitrogen oxides (NOx) and other pollutants. The revised caps, which the IMO is expected formally to adopt in October, would end shipping's dependence on the dirtiest, cheapest fuel - residual oil, a tar-like refinery waste product.