Steve Connor, The Independent 27 May 09;
Some people believe that nuclear power is the answer to climate change, others have proposed green technologies such as wind or solar power, but Barack Obama's top man on global warming has suggested something far simpler – painting your roof white.
Steven Chu, the US Secretary of Energy and a Nobel prize-winning scientist, said yesterday that making roofs and pavements white or light-coloured would help to reduce global warming by both conserving energy and reflecting sunlight back into space. It would, he said, be the equivalent of taking all the cars in the world off the road for 11 years.
Speaking in London prior to a meeting of some of the world's best minds on how to combat climate change, Dr Chu said the simple act of painting roofs white could have a dramatic impact on the amount of energy used to keep buildings comfortable, as well as directly offsetting global warming by increasing the reflectivity of the Earth.
"If that building is air-conditioned, it's going to be a lot cooler, it can use 10 or 15 per cent less electricity," he said. "You also do something in that you change the albedo of the Earth – you make it more reflective. So the sunlight comes down and it actually goes back up – there is no greenhouse effect," Dr Chu said.
When sunlight is reflected off a white or light-coloured surface much of that light will pass through the atmosphere and back into space, unlike the infrared radiation emitted from the Earth's warmed-up surface, which is blocked by greenhouse gases and causes global warming. "What we're doing is that, as we put in more greenhouse gases, we're putting in more insulation for infrared light. So if you make white roofs and the sunlight comes in, it goes right through that [insulation]," said Dr Chu.
The principle could also be extended to cars where white or "cool colours" designed to reflect light and radiation could make vehicles more energy efficient in summer. "If all vehicles were light-coloured, there could be considerable savings because then you can downsize the air conditioning... and downsizing the air conditioner means more efficient air conditioning and a considerable reduction in energy," he said.
Asked about whether the US administration has any plans to manipulate the climate artificially using large-scale geoengineering programmes, Dr Chu said there were no such plans "at this time". But painting surfaces white is one geoengineering proposal that he is taking seriously.
"Now you smile, but if you look at all the buildings and make all the roofs white, and if you make the pavement a more concrete-type of colour than a black-type of colour, and you do this uniformly... It's the equivalent of reducing the carbon emissions due to all the cars in the world by 11 years," he said.
"It's like you've just taken them off the road for 11 years. It's actually geoengineering."
The idea would even work in countries with temperate climates, such as Britain, because white-coloured roofs would help to reflect the radiated heat from homes and offices back into the building during winter months, said Dr Chu. One unresolved issue concerns the aesthetic considerations of making sloping roofs white. But with flat roofs that are not visible from the street, there should be no objection to painting them white, he said
Dr Chu is one of 20 Nobel prize-winning scientists attending a meeting on climate change at the Royal Society and St James's Palace organised by Cambridge University. He said energy efficiency will be the most immediate way of reducing emissions of greenhouse gases.
The white revolution: How it would work
* The idea of painting surfaces white to conserve energy is being actively pursued by the US. Earlier this month, Barack Obama's chief scientific adviser, John Holdren, received a scientific memorandum on the subject.
* Scientists estimate that making roofs and pavements white or more light-coloured would counter global warming with "negative radiative forcing" – reflecting sunlight back into space. They said that retrofitting urban roofs and pavements in tropical and temperate regions with solar-reflective materials would offset about 44 billion tonnes of carbon dioxide.
* The scientists said it would lower the cost of air conditioning, making buildings more comfortable and mitigate the "urban heat island" effect caused by the concentration of concrete surfaces in cities.
White roofs and 'cool' cars - Obama's US energy secretary gives Prince Charles tips on tackling climate change
Reflecting sunlight on buildings and cars among dozens of ideas considered by Steven Chu and the US energy department
John Vidal, guardian.co.uk 26 May 09;
People should paint their roofs white and drive "cool" cars on pale-coloured roads to avoid devastating climate change, US energy secretary and Nobel prize-winning physicist Steven Chu has advised Prince Charles and a group of 19 other laureates meeting in London today.
The measures, which would reflect sunlight and enable buildings and automobiles to stay cooler and use less energy in summer, are some of dozens that Chu and the US energy department are considering for the "revolution" which he said was needed in the US, Europe and around the world to address global warming.
"Yes, make people paint their roofs white. I think white is pretty. If all vehicles used cool colours then they could cut down the air conditioning and we would have a great reduction in energy," he said at the start of a three-day climate change symposium hosted by Prince Charles and attended by peace, literature, chemistry and physics laureates as well as 40 other senior scientists.
"This is a crisis. It's very serious. The earth will continue to warm up, even if we turned off energy use today. The carbon up there stays there for hundreds of years," said Chu, who has argued that coal is a "nightmare" and that science must be harnessed urgently to save the world from global warming.
"The industrial revolution was a revolution in the use of energy. It offloaded from human and animal power into using fossil fuels. We have to go to a new revolution that can severely decrease the amount of carbon emissions in the generation of energy," he said.
In less than six months Chu has transformed the US energy department from being driven by oil interests asunder President Bush's administration, to one which is now turning dramatically to renewable energy.
But he would not be drawn on the eventual cuts in greenhouse gas emissions which the US will adopt.
"Whether it is 17%, 20% or 25% [is not so important now]. There's an obsession with these percentages. But it's really important ... we get started. The US wants to decarbonise as swiftly as possible. We will go as fast as we can. I will do everything in my power to push the technologies."
He said he expected America to act before China in the run-up to the crucial UN climate change talks in Copenhagen in December. "I remain optimistic. The US should act first. Using China as an excuse not to act is no longer [appropriate]. If the US does act, we hope China will follow. The Chinese leadership knows about the consequences of climate change," he said.
But he warned against expecting too much of the US too soon. "We have to make a transition. If one does this very suddenly then there would be huge disruption. You need a lot of incentives, and some regulation. There is not one single policy that will save us."
Chu proposed that small teams of the best US scientists explore radical ways to reduce carbon in the economy. The targets for research include a new generation of nuclear power stations, a "smart" electricity grid, improved battery technologies, new energy standards, electric cars and highly efficient buildings.
The Obama administration today committed billions of dollars to improve the energy efficiency of homes and government buildings.
But Chu played down suggestions that it was was considering large-scale "geo-engineering" technologies like mirrors in space to reduce emissions.
The President of the Royal Society Lord Martin Rees, who was also at the symposium, said: "We need a completely new kind of energy economy that reduces dependency on fossil fuels. One species has the future of the planet in its hands. The best possible science should be employed to find the solutions. In buildings you can reduce energy consumption by 80% in a way that can pay for itself in 15 years — that is free money."
US wants to paint the world white to save energy
Yahoo News 26 May 09;
LONDON(AFP) (AFP) – US Energy Secretary Steven Chu said Tuesday the Obama administration wanted to paint roofs an energy-reflecting white, as he took part in a climate change symposium in London.
The Nobel laureate in physics called for a "new revolution" in energy generation to cut greenhouse gas emissions.
But he warned there was no silver bullet for tackling climate change, and said a range of measures should be introduced, including painting flat roofs white.
Making roads and roofs a paler colour could have the equivalent effect of taking every car in the world off the road for 11 years, Chu said.
It was a geo-engineering scheme that was "completely benign" and would keep buildings cooler and reduce energy use from air conditioning, as well as reflecting sunlight back away from the Earth.
For people who found white hard on the eye, scientists had also developed "cool colours" which looked to the human eye like normal ones, but reflect heat like pale colours even if they are darker shades.
And painting cars in cool or light colours could deliver considerable savings on energy use for air conditioning units, he said.
Speaking at the start of a symposium on climate change hosted by the Prince of Wales and attended by more than 20 Nobel laureates, Chu said fresh thinking was required to cut the amount of carbon created by power generation.
He said: "The industrial revolution was a revolution in the use of energy. It offloaded from human and animal power into using fossil fuels.
"We have to go to a different new revolution that can severely decrease the amount of carbon emissions in the generation of energy."
