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White Roofing as Silver Bullet to slay Global Warming?

September 15th, 2008 · 8 Comments

Reflective roofing has long seemed one of the best geoengineering options to help turn the rising tides of Global Warming. An opportunity to reduce energy use through reduced cooling demand and longer lasting roofs, to improve urban life (and cut energy requirements) by reducing urban heat island impacts, and to contribute to fighting global warming by reflecting solar radiation back into space.

It seems, however, that this opportunity might be even greater than previously believed. Global Cooling: Increasing World-wide Urban Albedos to Offset CO2 (pdf) suggests that white roofing of just 100 cities could handle Global Warming temperature increases.

This study comes from some of the nation’s top experts in roofing, from Heat Island Group at Lawrence Berkeley National Laboratory which focuses on this serious urban challenge:

“Heat Island research is conducted to find, analyze, and implement solutions to the summer warming trends occurring in urban areas, the so-called ‘heat island’ effect. We currently concentrate on the study and development of more reflective surfaces for roadways and buildings.”

According to Global Cooling,

a 1,000-square-foot roof — the average size on an American home — offsets 10 metric tons of planet-heating carbon dioxide emissions in the atmosphere if dark-colored shingles or coatings are replaced with white material.

Globally, roofs account for 25% of the surface of most cities, and pavement accounts for about 35%. If all were switched to reflective material in 100 major urban areas, it would offset 44 metric gigatons of greenhouse gases, which have been trapping heat in the atmosphere and altering the climate on a potentially dangerous scale.

That is more than all the countries on Earth emit in a single year. And, with global climate negotiators focused on limiting a rapid increase in emissions, installing cool roofs and pavements would offset more than 10 years of emissions growth, even without slashing industrial pollution.

This is quite impressive and a path that almost certainly is worth pursuing … even aggressive. To be clear, simply addressing temperature will not deal with all of the challenges related to CO2 emissions. For example, reflective roofing would do nothing relative to the acidification of the oceans and this threat to ocean (and human) life. But, the temperature impact in terms of cooling could be quite important in helping to create breathing space as humanity lowers its carbon footprint through reduced energy use combined with ever-more low/no-carbon energy sources.

The core geoengineering principle should be:

win-win-win. A proposal that, in a systems of systems effort, provides multiple wins and does not solely address temperature. Thus, a proposal that offers real potential for improving economy, reducing carbon, and contributing to reduced temperature (both directly, somehow, and indirectly through reduced carbon loads or carbon capture) would seem to merit greater prioritization than high-cost efforts that would solely impact “temperature” but not impact (or worsen) the carbon load equation.

And, this is the case with reflective roofing on a large scale,

“I call it win-win-win,” Akbari said. “First, a cooler environment not only saves energy but improves comfort. Second, cooling a city by a few degrees dramatically reduces smog. And the third win is offsetting global warming.”

Hat tip to Grist , EcoGeek, and Treehugger. LLBL press release.

Tags: Energy · climate change · energy efficiency · government energy policy

8 responses so far ↓

  • 1 Change. Obama can change the path of Climate Change! // Dec 7, 2008 at 11:19 pm

    [...] White roofing could be a Silver BB to slay global warming, Globally, roofs account for 25% of the surface of most cities, and pavement accounts for about 35%. If all were switched to reflective material in 100 major urban areas, it would offset 44 metric gigatons of greenhouse gases [...]

  • 2 The most important meeting in America? // Aug 11, 2009 at 5:17 am

    [...] first, when it comes to the built environment, is High-Albedo (White) Roofing (and other human infrastructure):  Secretary of Energy Steven Chu has brought attention to the [...]

  • 3 The most important meeting in America? | Eco Friendly Mag // Sep 17, 2009 at 10:39 pm

    [...] first, when it comes to the built environment, is High-Albedo (White) Roofing (and other human infrastructure): Secretary of Energy Steven Chu has brought attention to the great [...]

  • 4 McKinsey’s systematic under valuing of the value of efficiency // Jan 9, 2010 at 12:56 pm

    [...] a white or green roof saves energy costs on a building, but it also reduces the urban heat island impact and has a multiplicative impact reduces cooling [...]

  • 5 Advocates for climate mitigation again understate case? // Apr 28, 2010 at 9:00 am

    [...] office). Greening Schools improves student performance while saving money and reducing pollution. White roofing 100s of buildings in an urban area doesn’t save money for just one building owner due to [...]

  • 6 Climate Sanity and the necessity of Fully-Burdened Cost and Benefit Analysis // Aug 19, 2012 at 5:24 am

    [...] together reduce emissions far more than simply the sum of the individual actions. For example, a cool roofs initiative to switch from asphalt to white roofs not only reduces air conditioning costs to [...]

  • 7 Green Schools to Improve Educational Performance … and save money … and … // Sep 2, 2013 at 9:04 am

    [...] more longevity for components. For example, highly reflective (cool) or green roofs have roughly twice the longevity of asphalt roofs, thus not just leading to lowered energy costs but basically meaning that the roofs won’t [...]

  • 8 Greening Schools | Sense & Sustainability // Oct 18, 2013 at 7:16 am

    [...] more longevity for components. For example, highly reflective (cool) or green roofs have roughly twice the longevity of asphalt roofs, thus not just leading to lowered energy costs but basically meaning that the roofs won’t require [...]

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