Asking cargo ships to slow down could help combat climate change and save whales, according to a new paper part-funded by the EU.

The report suggests a 10 percent reduction in ship speed could result in a 19 percent drop in the amount of energy needed to power the ship. That means a 13 percent drop in carbon emissions, or 24 percent if speed is reduced by a fifth. 

The EU aims to reduce bloc-wide greenhouse gas emissions by nearly a third (from 1990 levels) by 2030. Shipping emissions make up around 3 percent of global greenhouse gas emissions, according to the International Council on Clean Transport.

Any cut to the emissions of the shipping industry could be vital in the fight against the climate emergency, because of the scale and importance of shipping on global trade.

According to the International Chamber of Shipping, the international trade association for the industry: "about 90% of world trade is carried by the international shipping industry".

Consultants GL Reynolds, who were asked to answer freight shipping's potential to reduce emissions, explained that a 10% reduction in speed translates to a 27% reduction in engine power demand - meaning less fuel has to be burned. 

Along with Carbon Dioxide (CO2), Black Carbon - a by-product of incomplete burning of fossil fuels, and what gives soot its color - is one of the worst pollutants affecting the global climate. According to the report, this substance represents 21% of the industry's emissions. 

"Black carbon has both adverse human health and environmental impacts. It is amongst the smallest of particulate material and is associated with health problems including respiratory and cardiovascular disease and cancer," the report added. 

The report also notes that underwater noise and whale collisions could be reduced by a global policy to slow cargo ships. Noise has long been a concern of marine biologists, and the report noted that although a complete reduction of propeller noise is out of reach, a drop of as much as 34 percent could be found via a speed reduction. 

Perhaps unsurprisingly, records of whales being accidentally struck and killed or injured by ships have been on the up since the 1800's, and as this report makes clear, it is the larger species of the sea-dwelling mammal that are most affected. 

If ships slow down, not only will they have more time to react and miss potential collisions, but they would be less likely to kill an whale they did hit.