Uber fares in London have gone up to help drivers buy electric cars, the company said.
A clean air fee of 15p per mile will be added to every trip taken in the capital from Wednesday.
The ride-hailing firm expects the scheme to raise more than £200m in the coming years, which will be used to help drivers convert to electric cars.
Uber said it was "keen to expand" the initiative to other UK cities to help curb air pollution.
The fee would add about 45p to the average London journey, it added.

A London driver using the app for an average of 40 hours per week would be given around £3,000 towards buying an electric car in two years, according to the company.
The clean air fee will not include miles travelled to a passenger's pick up location and will not be affected by dynamic pricing.
Uber hopes to hand cash to 20,000 of its 45,000 drivers in London drivers to help them switch by 2021, increasing to every car by 2025.
Uber chief executive Dara Khosrowshahi said: "Our £200m Clean Air Plan is a long-term investment in the future of London aimed at going all-electric in the capital in 2025."
London mayor Sadiq Khan introduced a £10 toxicity charge for older, more polluting vehicles in the centre of the capital in October 2017.
This will be replaced by an Ultra Low Emission Zone from April, which will create stricter emissions standards for diesel vehicles at all times.
A spokeswoman for the Mayor of London said Uber's recognition on the importance of clean air was a "positive step".
Source: bbc.com