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Global warming scientists foresee Sun-reflecting cities

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PARIS — Scientists sketched a vision on Friday of converting the world’s cities into giant sunlight reflectors to help fight global warming but met with scepticism from fellow academics.

Gradually replacing traditional urban roofs and roads with white or lighter-coloured materials would yield a cooling benefit that, over 50 years, would be the equivalent of a reduction of between 25 and 150 billion tonnes of carbon dioxide (CO2), researchers in Canada said.

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At the top end of the scale, this equals the emissions of all the world’s cars over the same period, their study published in Britain’s Institute of Physics’ journal Environmental Research Letters stated.

Light-coloured materials help reflect the Sun’s rays rather than absorb and convert them into heat, a phenomenon known as albedo in scientific terms.

Pavements and roofs make up more than 60 percent of urban surfaces and, by trapping solar energy, are largely to blame for “heat islands”, where cities or districts become local hotspots.

Urban heat islands also gobble up energy in air conditioning and inflict health costs through smog.

The cost of reflectors need not be prohibitive as rooftops and paved surfaces need to be resurfaced every so often anyway, the scientists argued.

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“All it means is that when the time comes, they would select a cool roof,” Hashem Akbari of Concordia University in Montreal told AFP.

He conceded that some of the new materials may be slightly more expensive than before, but the cost would still be “lower than the … savings they produce” in cooling.

French climate consultant Jean-Marc Jancovici, however, said the proposals would have only a localised effect.

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“If you decrease significantly the temperature in local places with something like painting the roofs in white, it doesn’t ensure that you will have a decrease in the temperature in remote places,” he said.

Alfredo Stein of the Global Urban Research Centre at Britain’s University of Manchester also predicted practical difficulties, particularly for the world’s sprawling slum areas.

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“It will require very strong advocacy by whoever will be selling the roofs,” he told AFP, especially considering that about 70 percent of houses worldwide are built by the owners themselves, mainly in informal settlements.

People’s choices for roofing materials are largely determined by affordability and availability, Stein argued.

In a 2009 probe into so-called geo-engineering options to brake global warming, Britain’s Royal Society gave low marks to “white roof” methods.

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There would be benefits locally in hot countries, it said.

But only 0.05 to one percent of the world’s land surface would be covered, which meant it would lack effectiveness on a global scale, the prestigious academy said.

And it estimated the cost at “about $300 billion a year, making this one of the least effective and most expensive methods considered.”


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Donald Trumps needs a coronavirus scapegoat — and right now it’s China

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"If we are at war, who is the enemy?" asks Fred Hiatt, editorial page editor for The Washington Post in a smart piece that examines the question of who constitutes a target for a self-declared "wartime president."

While it is obvious that the enemy, in this case, is a tiny, sticky, invisible microbe that stubbornly gloms onto surfaces or leaps through the air to weaponize subway cars or shared gym equipment or a touch to the face.

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Trump says Putin to ‘probably ask’ for sanctions lifting

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President Donald Trump said Monday he expects his Russian counterpart Vladimir Putin to request the lifting of US sanctions during an upcoming phone call.

"Yeah, he'll probably ask for that," Trump told Fox News.

Trump did not say what his response would be, noting that he had put sanctions on Russia but adding: "They don't like that. Frankly we should be able to get along."

The two were due to talk "shortly," he said.

Last Thursday, Putin told G20 leaders during a conference call that he wanted a moratorium on sanctions as a "matter of life and death" during the global coronavirus outbreak.

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Arguing with the coronavirus deniers in your life can backfire — here’s how to make them see the light

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For those of us diligently practicing social distancing, it can be infuriatingly frustrating to encounter friends and loved ones who refuse to. There’s a strong temptation to lash out at them as selfish fools whose irresponsibility endangers us all. But doing so will backfire because, when people feel attacked, they get defensive and entrench in their position. Like it or not (not!), this is human nature.

Your civic duty, in addition to social distancing, is to talk to Covid-deniers in a way that has some chance of getting through to them. Here are some do’s and don’ts from the world of cross-partisan dialogue best practices that apply to the Covid-19 pandemic:

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