Greenhouse gas emissions

In the study, which took place in Germany, scientists trained the animals to use a designated toilet. Their urine was then collected and treated.

The ammonia from cows' urine turns into the greenhouse gas nitrous oxide when it's mixed with soil.

Worldwide, about 10% of all greenhouse gas emissions from human activities comes from cattle.

Researchers attempted to teach 16 cows to use the toilet, dubbed the "MooLoo", at a farm owned by the Research Institute for Farm Animal Biology.

The agreement came at the end of a week-long meeting of the International Maritime Organisation, a United Nations body, in London, where small countries were pitted against large shipping nations that were against such restrictions.

Friday's agreement calls for global shipping emissions to peak as soon as possible, and to reduce the total annual greenhouse gas emissions by at least 50 percent of 2008 levels by 2050. It also calls for efforts to be pursued to phase out greenhouse gas emissions from shipping entirely.