Painting roofs white is as green as taking cars off the roads for 50 years, says study

 

A A A

Painting roofs white and using light-coloured materials to surface roads and pavements would not only make cities cooler in summer, it would save the same amount of carbon as taking all the cars in the world off the roads for 50 years, a study has found.

One of the simplest, yet most effective, ways of engineering the urban environment to cope with global warming is to increase the reflectivity of the cityscape so that more of the incoming sunlight is directed back into space, scientists said.

City buildings in warm climates with "cool coloured" surfaces that reflect infra-red radiation would also be cooler than traditional buildings and so would conserve energy – and carbon – that would otherwise be used on air conditioning.

Increasing solar reflectance or "albedo" has been suggested as a way of combating the "heat island" effect of towns and cities, where summers are made unbearably hotter in built-up areas by Tarmac roads and dark buildings that absorb sunlight.

Two years ago, Barack Obama's top man on global warming, Professor Steven Chu, the US Secretary of Energy, suggested at the Royal Society in London that one of the most effective engineering measures to tackle rising temperatures is to paint roofs.

"If the building is air-conditioned, it's going to be a lot cooler, it can use 10 or 15 per cent less electricity... you also do something in that you change the albedo of the Earth – you make it more reflective," Professor Chu said. Now scientists, led by Professor Hashem Akberi, of Concordia University in Canada, have studied this in detail and found that it can have a significant impact.

They estimate that a city or town where the roofs and the pavements and roads have light-coloured surfaces can increase their albedo by about 10 per cent, which globally would provide a CO2 offset of between 130 billion and 150 billion tonnes – the same as taking every car in the world off the road for 50 years.

"Increased albedo can decrease atmospheric temperature and counter some of the anticipated temperature increases from global warming," the scientists say in the journal Environmental Research Letters.

Albedo is measured on a scale of zero to one, where 1.0 is totally reflective and zero absorbs all sunlight.

The researchers believe that it would be cheap and easy to increase the albedo of cities by applying the reflective materials when roofs and roads are routinely resurfaced, rather than doing it as a special measure.

Arts and Entertainment
The eyes have it: Kate Bush
music
Arts and Entertainment
booksNovelist takes aim at Orwell's rules for writing plain English
Arts and Entertainment
Al Pacino in ‘The Humbling’, as an ageing actor
filmHam among the brilliance as actor premieres two films at festival
News
Fifi Trixibelle Geldof with her mother, Paula Yates, in 1985
people
PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
Sport
Mario Balotelli in action during his Liverpool debut
football ...but he can't get on the scoresheet in impressive debut
Environment
Pigeons have been found with traces of cocaine and painkillers in their system
environmentCan species be 'de-extincted'?
Arts and Entertainment
booksExclusive extract from Howard Jacobson’s acclaimed new novel
News
i100
Arts and Entertainment
A Pilgrim’s Progress is described by its publisher as “the one-and-only definitive record” of David Hockney's life and works
people
Sport
Loic Remy signs for Chelsea
footballBlues wrap up deal on the eve of the transfer window
News
i100
Arts and Entertainment
Art
Arts and Entertainment
Elizabeth McGovern as Cora, Countess of Grantham and Richard E Grant as Simon Bricker
TV
Life and Style
Instagram daredevils get thousands of followers
techMeet the daredevil photographers redefining urban exploration with death-defying stunts
Arts and Entertainment
Diana Beard, nicknamed by the press as 'Dirty Diana'
TVDaughter says contestant was manipulated 'to boost ratings'
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Web Developer (Infrastructure, JavaScript, jQuery, jQuery UI)

Negotiable: Harrington Starr: Web Developer (Infrastructure, JavaScript, jQuer...

DT Technician

£65 - £80 per day: Randstad Education Cardiff: DT Technician required to start...

Trainee Recruitment Consultant - Manchester - Huxley Associates

£18000 - £23000 per annum + Commission: SThree: One of SThree's most successfu...

Nursery Manager

£10 - £11 per hour: Randstad Education Cheshire: Nursery Manager We are loo...

Day In a Page

Alexander Fury: The designer names to look for at fashion week this season

The big names to look for this fashion week

This week, designers begin to show their spring 2015 collections in New York
Will Self: 'I like Orwell's writing as much as the next talented mediocrity'

'I like Orwell's writing as much as the next talented mediocrity'

Will Self takes aim at Orwell's rules for writing plain English
Meet Afghanistan's middle-class paint-ballers

Meet Afghanistan's middle-class paint-ballers

Toy guns proving a popular diversion in a country flooded with the real thing
Al Pacino wows Venice

Al Pacino wows Venice

Ham among the brilliance as actor premieres two films at festival
Neil Lawson Baker interview: ‘I’ve gained so much from art. It’s only right to give something back’.

Neil Lawson Baker interview

‘I’ve gained so much from art. It’s only right to give something back’.
The other Mugabe who is lining up for the Zimbabwean presidency

The other Mugabe who is lining up for the Zimbabwean presidency

Wife of President Robert Mugabe appears to have her sights set on succeeding her husband
The model of a gadget launch: Cultivate an atmosphere of mystery and excitement to sell stuff people didn't realise they needed

The model for a gadget launch

Cultivate an atmosphere of mystery and excitement to sell stuff people didn't realise they needed
Alice Roberts: She's done pretty well, for a boffin without a beard

She's done pretty well, for a boffin without a beard

Alice Roberts talks about her new book on evolution - and why her early TV work drew flak from (mostly male) colleagues
Get well soon, Joan Rivers - an inspiration, whether she likes it or not

Get well soon, Joan Rivers

She is awful. But she's also wonderful, not in spite of but because of the fact she's forever saying appalling things, argues Ellen E Jones
Doctor Who Into the Dalek review: A classic sci-fi adventure with all the spectacle of a blockbuster

A fresh take on an old foe

Doctor Who Into the Dalek more than compensated for last week's nonsensical offering
Fashion walks away from the celebrity runway show

Fashion walks away from the celebrity runway show

As the collections start, fashion editor Alexander Fury finds video and the internet are proving more attractive
Meet the stars of TV's Wolf Hall... and it's not the cast of the Tudor trilogy

Meet the stars of TV's Wolf Hall...

... and it's not the cast of the Tudor trilogy
Weekend at the Asylum: Europe's biggest steampunk convention heads to Lincoln

Europe's biggest steampunk convention

Jake Wallis Simons discovers how Victorian ray guns and the martial art of biscuit dunking are precisely what the 21st century needs
Don't swallow the tripe – a user's guide to weasel words

Don't swallow the tripe – a user's guide to weasel words

Lying is dangerous and unnecessary. A new book explains the strategies needed to avoid it. John Rentoul on the art of 'uncommunication'
Daddy, who was Richard Attenborough? Was the beloved thespian the last of the cross-generation stars?

Daddy, who was Richard Attenborough?

The atomisation of culture means that few of those we regard as stars are universally loved any more, says DJ Taylor