LONDON - Green infrastructure - from more cycle lanes to cleaner air - not only helps the environment but also boosts jobs, health and productivity, according to research released on Wednesday.
Spending money on improved public transport could create up to 23 million extra jobs each year, according to researchers at the University of Leeds in Britain.
The team analysed more than 700 papers on the impact of low-carbon infrastructure on cities around the world.
By turning new and existing buildings into energy-efficient spaces, cities can generate a further 16 million jobs, said the report, which was commissioned by the Coalition for Urban Transitions, a group of think tanks, institutes and universities pushing for more sustainable cities.
Investing in cycling routes was also worth between $35 and $136 billion a year in public health benefits, the report added.
"As the evidence mounted up, we were struck by the fact that the cities we want - cleaner, healthier, richer - are made possible through climate action," said lead author of the study, Andy Gouldson, a professor at the University of Leeds.
"Whether high-quality public transport or segregated cycling lanes, energy-efficient buildings or better waste management, the dollars, lives and hours saved are impressive," he said in a statement.
Two in three people will be city dwellers by 2050, with the boom concentrated in India, China and Nigeria, according to United Nations estimates released in May.
As of today, 55 percent of the world's population lives in urban areas, increasing to 68 percent by 2050, according to the report on urbanisation by the Population Division of the U.N. Department of Economic and Social Affairs.
The world already has 33 megacities - the largest urban hubs - with another 10 megacities expected to take shape by 2030, mostly in developing countries, the UN report said.
"Governments face a number of urgent challenges in cities: delivering decent services, ensuring a healthy environment, creating economic opportunities for residents," said economist Sarah Colenbrander from the Coalition for Urban Transitions.
"Low-carbon investment in cities can help meet the needs of residents today, while protecting cities for residents of the future," she said in a statement.