LONDON-Cutting the speed of ships has huge benefits for humans, nature and the climate, according to a new report.

A 20% reduction would cut greenhouse gases but also curb pollutants that damage human health such as black carbon and nitrogen oxides. This speed limit would cut underwater noise by 66% and reduce the chances of whale collisions by 78%. UN negotiators will meet in London this week to consider proposals to curb maritime speeds.

Ships, of all sorts and sizes, transport around 80% of the world’s goods by volume. However they are also responsible for a significant portion of global greenhouse emissions thanks to the burning of fuel.

Shipping generates roughly 3% of the global total of warming gases - that’s roughly the same quantity as emitted by Germany.

While shipping wasn’t covered by the Paris climate agreement, last year the industry agreed to cut emissions by 50% by 2050 compared to 2008 levels.

This new study, carried out for campaign groups Seas at Risk and Transport & Environment builds on existing research that suggests that slowing down ships is a good idea if you want to curb greenhouse gases.

The report though also considers a range of other impacts of a speed cut such as on air pollution and marine noise.

As ships travel more slowly they burn less fuel, which means there are also savings in black carbon, sulphur and nitrogen oxides. The last two in particular have serious impacts on human health, particularly in cities and coastal areas close to shipping lanes.

The report found that cutting ship speed by 20% would cut sulphur and nitrogen oxides by around 24%. There are also significant reductions in black carbon, which are tiny black particles contained in the smoke from ship exhausts.