How painting roofs white can help ‘turn off the world for a year" | RenewEconomy

How painting roofs white can help ‘turn off the world for a year”

What could be more boring than painting a roof white? Turns out, it’s also an important solution for reducing energy use and lowering carbon dioxide emissions.


I’m drawn to “boring” ways to change energy use: things like daylighting, reducing packaging, and making company supply-chains more efficient. Without these methods to help reduce our energy demand, the “exciting” solutions like renewable energy are less valuable.

And what could be more boring than painting a roof white? Turns out, it’s also an important solution for reducing energy use and lowering carbon dioxide emissions.

A NASA survey of New York City’s rooftops last July showed that dark, heat-absorbing rooftops were up to 42 degrees F hotter than white rooftops. And that difference in heat can make a big difference in on-site energy use; painting a roof white can reduce air conditioning demand as much as 20 percent.

In February, researchers at Concordia University estimated that painting one percent of the world’s urban surfaces white (rooftops and pavement) could reduce CO2 emissions by 130 gigatons over the next 50-100 years. In 2011, global CO2 emissions from fossil fuel combustion reached 31.5 gigatons.

Clearly, white roofs are a major opportunity. But while we’ve seen a proliferation of companies selling on-site solar and efficiency services, there’s been only modest activity in this market. Why aren’t more companies jumping on this around the country?

“I’m not sure why an organization doesn’t exist like this in every city. And it should,” says Juan Carlos, founder of the White Roof Project, a non-profit based in New York City that harnesses volunteers to provide roof painting services.

Having found a good niche with decent demand, the organization is now trying to branch out of New York and take its rooftop painting model nationwide. According to Carlos, painting 5% of the world’s rooftops white per year by 2030 could save enough emissions to equal the world’s carbon output in 2010.

“That would essentially turn off the entire world for an entire year,” he says.

With cities around the world adopting building codes to promote white roofs, the opportunities for this solution are increasing. But we’ve still got a long way to go before we can service so many rooftops per year.

This story first publised in Climate Progress. Reproduced with permission.

Print Friendly, PDF & Email

  1. Gary 8 years ago

    Practical and effective Stephen, is the answer. Less complicated than a carbon tax and the money market, as a solution to reducing carbon. There are so many others aspects to this that have been developed in Europe in the last 15yrs. A google search for EcoMapping will deliver more than you can imagine. I put this to many political representatives 2years ago and didn’t even receive a response from the Christine Milne. Efficiency and better strategic design on worksites and between activities now on different sites can more than halve production costs and GHG emissions. Including safety review can also make a direct approach to worksite risks. Intrusion of industrial fallout into residential areas can be reduced. Stress and general health issues that are a function of this can be reduced. The cost may seem casual, but it is in fact $Billions of dollars annually. So disappointing such engaging processes are not sold in a way that would excite our community and future business innovation. An opportunity for you Stephen to pick up further excitement in telling the world there is more in it for all, if we were to be more considerate in our application of logic.

  2. Beat Odermatt 8 years ago

    Yes, most good solutions are simple and cheap like painting a roof white. Unfortunately we have a lot of “leaders” highly skilled in the art of finding the most complicated unworkable, but expensive way of making a simple thing more complicated!

  3. Gillian 8 years ago

    Australia is well ahead on this one. The NSW BASIX index includes roof colour, and Queensland is seeing a revival of classic Queenslander houses with their climate-friendly metal roofs, verandahs, window awnings and off the ground breezy construction.

    Blogged here…

    Who needs NASA to tell you the obvious?

  4. Graeme 8 years ago

    You could go one step further than just painting your roof white and use an Australian invention that’s effectively a passive heat pump –

    An amazing products that’s water based, inert, long life and fully proven by several Australian university tests on used on building such as Melbourne Airport.

    In case you’re wondering I DON’T work for the company but believe in this Australia product as it is truly an amazing coating that should be seriously looked at by an Facility Manager looking to significantly reduce his or her energy costs with the added benefit of extending the life of their roof.

    • Bonzo 8 years ago

      Yes, and here’s another similar innovation from UTS, the advantage being the extracted heat is radiated into space so does not contribute to global warming: And no I don’t work for UTS!

  5. James 4012 8 years ago

    There may well be a problem in inner city areas regarding the reflective effects of white roofs and glare. White footpaths and people with reduced vision would also be an issue.

  6. Petra 8 years ago

    But what about winter? Don’t we spend more on heating than on cooling, at least in the southern states. I definitely wouldn’t paint my roof white – our house is OK in summer but freezing in winter.

    Another way to save on energy is to simply use less air-conditioning power. So many places are like fridges.

  7. Concerned 8 years ago

    I built my house 25 years ago, and installed a white metal roof. House bulit with foam insulation in the walls, corectly orientated.Brisbane.
    This knowledge(white roofs etc) has been around for centuries.

  8. Beat Odermatt 8 years ago

    It seems that some clever innovations did occur a long time ago. People in remote areas never had the luxury of plentiful cheap energy to either cool or heat their home. They used passive ways to keep warm and to stay cool. Homes in many hot arid areas where painted white and homes in cold areas where often dark or covered in turf.
    We can look to the past and find solutions for the future!

Comments are closed.

Get up to 3 quotes from pre-vetted solar (and battery) installers.