Category Archives: Uncategorized

American Institute of Architects Recognizes the Benefits of Cool Roofs

In April of this year, GCCA Board Member Greg Kats published a study of the health benefits of cool roofs on Washington DC-owned buildings. After the District retrofitted many of its buildings with white roofs, green roofs, and / or solar collectors the city started saving money. This study turns things on its head by showing that using the old technology of conventional dark roofs is a policy failure that costs cities and building owners money.

Robert Ivy, chief executive of the American Institute of Architects discusses this study, along with other cool roof benefits in this Washington Post guest column. In it, he notes that the highly reflective surfaces of white roofs cut energy bills and can help improve the health of residents and cool cities.

“We’ve known for years that smart roofs save energy, and we’ve been able to come up with methodologies to quantify those savings. However, the health benefits of such design choices have been harder to figure out. The authors of this report, Greg Kats and Keith Glassbrook, have addressed this complex question, and their findings could have an impact on improving the health of residents in urban areas across the nation.

Roofs typically make up 15 to 25 percent of most cities’ surface areas. And because roofs can typically be replaced or retrofitted more frequently than entire buildings, they represent an opportunity for developers and building owners to dramatically cut the “heat island effect” in urban environments …

Use of such techniques, in turn, can have public health benefits, particularly for low-income and elderly residents who tend to be more vulnerable to illnesses related to extreme heat and poor air quality. Moreover, heat mitigation through adoption of cool and green roofs can help ameliorate the effects of heat stress.

The report will prove to be relevant reading for designers, architects or city officials trying to battle the pernicious health effects of urban heat islands. These new methodologies suggest ways for cities to quantify the benefits of their building codes, policies and incentive programs.”

You can read the full report here:
Washington, DC Smart Roof Cost – Benefit Report

Cool Roofs Save Lives During Global Killer Heat Waves

NOAA has been tracking rising temperatures around the world and it seems each month we see new reports of record setting heat. According to NOAA records, May was the hottest year on record, and it looks like 2015 is on track to beat last year for overall temperatures. Extreme heat events are happening all over the world and this heat is killing thousands. Take a look at a weather map of this global heat wave…

[image of Summer 2015 heatwave India]

In Australia, a heat-wave killed 374 people earlier this year. Doctors see this a public health emergency, and are calling for climate action to head off this silent killer.

In India, the heat was so bad the roads were literally melting, with temperatures reaching 118 Fahrenheit in some areas. India’s Earth Sciences Minister – Harsh Vardhan – has blamed climate change for a heatwave that killed 2,500 people in late May and early June.

“Let us not fool ourselves that there is no connection between the unusual number of deaths from the ongoing heat wave… It’s not just an unusually hot summer, it is climate change”

[image of Heatwave India 2015]

In Pakistan, over 65,000 people have suffered heat stroke in a recent heatwave – which has killed over 1,200 people. Peak temperatures have reached 48 degrees Celsius / 118 degrees Fahrenheit.

People are starting to understand how low-cost solutions like cool surfaces are saving lives. Especially in the developing world. The life-saving benefits of cool and white roofs are discussed in this Mashable article about the heat waves in Pakistan and India…

“You don’t necessarily need a complicated solution,” Jaiswal said. She pointed to Sherdaben General Hospital in Ahmedabad, a hospital which serves a slum community, as an example where a low-tech, low-cost solution saved many lives.

The hospital had a black tar roof, which increased the building’s temperatures. Further, the neonatal ward was on the highest floor, meaning that many mothers and their newborns were put at greater risk of heat-related illnesses.

The solution? The hospital installed a white roof, which lowered the internal temperature of the building significantly, and the staff also moved the neonatal ward to a lower floor.”

Heatwaves are also hitting the Southeast United States, Alaska, Israel and Japan igniting wildfires and sending hundreds to the hospital, according to this article in EcoWatch. Temperatures average 5 – 15 degrees higher than normal with some areas hitting 115 degrees Fahrenheit. Extreme heat and record-setting temperatures as high as 120 degrees Fahrenheit triggered wildfires in the Northwest United States.

Meanwhile, a potentially record-setting heatwave is projected for Spain, the United Kingdom, France, Belgium, the Netherlands and Germany at the end of June.

These extreme heat events will only become more frequent and more deadly. According to a new report by the British medical journal, The Lancet, more people will be exposed to heat waves and other extreme weather linked to climate change over the next century. From The New York Times

“By the end of the century, the report estimates, the exposure to heat waves each year for older people around the world is expected to be around 3 billion more cases than in 1990.”

Extreme heat is the silent killer – the most deadly of natural disasters, and GCCA has collected data and produced reports detailing how cool surfaces can save lives as our planet warms. For additional information, please read our reports:

Assessing the Health Impacts of Urban Heat Island Strategies in the District of Columbia
Health Impacts of Urban Cooling Strategies in Baltimore, Los Angeles and New York City

National Adaptation Forum

Last week, GCCA joined over other 825 professionals in St. Louis last week to discuss the latest in urban-scale climate adaptation at the National Adaptation Forum. It was a great and energizing opportunity to meet with a diverse set of representatives from cities, tribes, utilities, and the private sector who share a common goal to better prepare their communities for the impacts of climate change.

We were honored to be included in a panel on urban heat islands which included David Fink from Climate Resolve, Emma Zinsmeister of EPA, and Kate Johnson of the District Department of the Environment. Turnout was great and the discussion afterwards was even better – so many people interested in understanding and acting to reduce excess urban heat in their area.

Check out this website for more information on the Forum, including all of the presentations. You can download my presentation here.

The Power of Cool Coatings!

The Northern Cape Province of South Africa is mainly semi-desert. In January, afternoon temperatures usually range from 34 to 40 degrees Celsius. In 1939, an all time high of 47.8 degrees Celsius was recorded at the Orange River.

Summer temperatures often top the 40 degree mark in this region (104 Fahrenheit).

This video explains how cool surfaces can help reduce indoor temperatures and improve the quality of life of those living in low-income housing in this scorching environment.

Reflective surfaces are cool in more ways than one, reducing energy consumption and saving lives one building at a time!

France Mandates Sustainable Roofs

France has recently approved a requirement that new commercial roofs must be partially covered with vegetation or solar panels.  This is a first of its kind requirement, and has generated a lot of coverage as a result, including National Geographic, Architecture and Design, Triple Pundit, and many others.

This requirement is an exciting step to spur a larger and economically efficient market for a wide variety of sustainable cool roofs!

GCCA Part of Coalition to Study Benefits of Smart Roofs on Affordable Housing

n response to growing interest in understanding the health, economic, social, and energy implications of greener affordable housing, GCCA partnered with clean energy and green building research and advising firm, Capital E, and several national non-profits (including AIA and USGBC), to study the costs and benefits of smart roof technologies.  Based on a first-of-its-kind analyses of four multi-unit affordable housing properties in Washington, DC, Baltimore, Philadelphia, and Los Angeles, the study presents a rigorous and comprehensive cost-benefit analysis of four rapidly growing roof technologies—cool roofs, green roofs, solar PV, and solar thermal—that will be invaluable for policymakers and developers alike.  The report, authored by Capital E and funded by a grant from The JPB Foundation, finds that cool roofs, green roofs, solar PV, and solar thermal provide large financial, health, and environmental benefits in most cities studied.

You can read more about it by clicking here.

A Standard is Born

GCCA Board Member Ronnen Levinson just announced the publication of ASTM D7897-15, ‘Standard Practice for Laboratory Soiling and Weathering of Roofing Materials to Simulate Effects of Natural Exposure on Solar Reflectance and Thermal Emittance’.

This practice was developed and shepherded through ASTM by the LBNL Heat Island Group and by Concordia University, with support from DOE’s Building Technologies Office, and from many industrial and academic partners. It will be used to accelerate the development and deployment of cool roofing materials, and has already been accepted for interim rating of roofing products by the Cool Roof Rating Council (CRRC) and by California’s Title 24 Building Energy Efficiency Standards. The CRRC and LBNL will offer courses at LBNL next month to train and certify test laboratories. Research is underway to adapt the method for use in China, India, and Europe.

While they work with the Berkeley Lab News Center to prepare a release, you can read this earlier write-up describing the acceptance of the practice by CRRC and CA Title 24.  You can also learn more about the method itself in the first half of this eight-minute Science at the Theater talk, Cool Roofs Though Time and Space, and in their 2014 SOLMAT article.

Video Explains How Reflectivity Can Change Over Time

GCCA Board Member and researcher at the Lawrence Berkley National Laboratory’s Heat Island Group, Ronnen Levinson, explains how the reflectivity of cool roofing materials can change over time in this new video. He also introduces LBNL’s new California Cities Albedo Map, which estimates the reflectivity of roofs in five California cities.

You can find more great videos at GCCA’s new YouTube Channel.

Studies Draw Direct Line from Climate Change to Extreme Heat and Drought

A new report from the Climate Council of Australia confirms what many have long suspected – that human-caused climate change makes heat waves more certain and more extreme. 2013 was the hottest year on record in Australia, and as this report notes, the 2012 / 2013 heat waves would have been “virtually impossible” without the release of human-made greenhouse gas emissions into our atmosphere.

It also found that climate change tripled the odds that the heat waves would occur as frequently as they did, and doubled the odds that they would be as intense as they were. More than 123 temperature records were broken during that summer, and the author of the report – Will Steffen – said that these temperatures will seem cool by 2090 unless we act now.

Thankfully, Australia is already using reflective technology to help bring temperatures down.  In the City of Melbourne, City administrators know that with the increased frequency and intensity of heatwaves, they need to understand the economic impacts of such events on businesses.  From the City of Melbourne

 “We’re doubling tree canopy cover for our urban forest, upgrading drainage infrastructure, funding more energy efficient buildings, implementing planning processes to minimise climate risk and installing various water-sensitive urban design initiatives.  Heatwaves don’t only impact our city economically, heat related illness also kills more Australian’s each year than any other natural disaster so City of Melbourne has identified this as a priority issue we must prepare better for,” Cr Wood said.

Meanwhile, the City of Sydney is conducting a trial to see if lighter colored pavement will help reduce the urban heat island effect and improve the comfort and health of the people who live there.

People on the west coast of the United States are also feeling the effects of climate change.  A recent study published in the Proceedings of the National Academy of Science shows that greenhouse gas emissions have increased the likelihood of warm, dry conditions in California, and that by 2030, the warm weather driving the current drought could occur annually.

This problem isn’t just confined to California.  According to The National Integrated Drought Information System (, 32% of contiguous USA is in moderate or worse drought.

Thankfully, cities in the Golden State are already on it. A new law went into effect in the city of Los Angeles last year that requires white roofs on all new construction and major rebuilds of residential buildings. Commercial and residential buildings are now required to employ reflective roof technology to help bring city temperatures down. The cities of Pasadena and Hermosa Beach have enacted similar regulations – you can read more about it here.

The problems brought on by extreme heat and climate change are many. But many city leaders around the world are recognizing the benefits of reflective roofs and pavements, and are using this technology to conserve energy, reduce emissions, and save lives.

Climate Change and Geoengineering

There has been a lot of press coverage of the decision by the National Academy of Science to study the feasibility and safety of large-scale geoengineering as a means to address climate change. It is hard to believe that we are at a stage where we must consider such drastic strategies.

Much of the conversation has revolved around the idea of albedo modification — that is, increasing the amount of solar energy reflected into space rather than absorbed by earth. Conceptually, this is the same process that keeps light colored roofs and pavements cooler. However, the scale of the geoengineering being considered is staggering — we are talking huge swaths of the earth brightened by man-made clouds. Since only 1% of earth’s surface is urban, even a wildly successful global cool roofs and pavements campaign would be nearly 70 times smaller in scale than what is under study now. There really is no comparison.

And yet, focusing efforts of deploying more cool roofs and pavements would have a tremendously positive impact on the planet. They help cut cooling energy and peak electricity demand, improve heat resiliency of people living in unconditioned buildings, and cool down communities and help reduce air pollution; all while safely offsetting the warming effect of atmospheric greenhouse gases.

The scientific debate is on about whether we have reached a point where we must consider drastic measures to combat climate change. Either way, we should be taking the simple and affordable first steps to improve our buildings, communities, and planet by installing cool roofs and pavements anywhere it makes sense to do so.