Now here's the answer for Toronto

Sheep urine cuts pollution

A British bus company is testing a new secret weapon to reduce polluting emissions - sheep urine.

Stagecoach has fitted a bus in Winchester with a tank containing the waste, reports the Guardian.

The urine is sprayed into exhaust fumes to reduce emissions of harmful nitrous oxides.

Andrew Dyer, managing director of Stagecoach South, said: "It is a novel way of reducing pollution but we believe it will work.

"This is the latest in green technology and we believe it will help make our cities better places to be for the public."

The scheme is backed by Hampshire county council as part of an effort to reduce pollution. The bus carried its first passengers last month.

The urine is collected by the fertilizer industry from farmyard waste and refined into pure urea, which is then sold on to be used in the green engine technology.

Ammonia from the urea reacts with nitrous oxides in the exhaust fumes and converts them to nitrogen gas and water, which is released as steam.