London will lead the way toward green transport with the first zero-emission electric double-deck bus to be deployed in October.

The bus manufactured by BYD will enter service route 16 running between Cricklewood and Victoria Station.

Mayor Boris Johnson announced the plan at the recent Clean Bus Summit in the city.

At the summit, around 24 cities around the world also committed to put ultra-low emission buses on the road. It also saw bus manufacturers including BYD, Volvo, Wright Bus, Optare Mercedes Evo Bus and Alexander Dennis pledge their support to the cities by delivering fleets of new ultra-low emission buses.

The World Bank and Green Investment Bank have also signed up to this commitment.

All new buses joining central London's fleet are now ULEZ-compliant, delivering important air quality improvements, noted the mayor in a press statement.

London introduced its first hybrid buses numbering 1300 since 2008 with many more older ones retrofitted to cut emissions.

More of the new retrofitted Routemasters, which are said to be the cleanest double-deck buses, will be deployed on London's streets by 2016.

London will breathe easier

The low emission buses will reduce CO2 emissions in the city by around 27,500 tonnes a year. The nitrous oxide emissions will also be halved, helping the battle against pollution.

The new all-electric buses were produced in conjunction with BYD, which worked to fit enough batteries into the buses to provide adequate power.

London will also see two Irizar-made electric single-deck buses join eight others manufactured by Optare and BYD that have been used successfully in London's fleet since 2013.

The 24 other cities will also deploy 40,000 ultra-low emission buses on the road by 2020.

Transportation is the fastest growing source of carbon emissions and accounted for about 2,300 megatonnes of CO2 in 2010.

Vehicular growth in developing countries has seen transport emissions rise with China's figures predicted to go from 190 megatonnes annually to nearly 1,200 megatonnes and India's from about 70 megatonnes today to over 500 megatonnes.

Studies have shown that these can be almost halved by an efficient public transport system.

Nearly 1.4 million early deaths have been associated with exposure to tailpipe emissions.
Diesel black carbon soot emissions, besides abetting climate change, also has been shown to cause around 3.2 million deaths.