Tag Archives: urban heat island

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

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 (Drought.gov), 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.

Northern Cities Run Hot and Cold

You wouldn’t look at a list of the 50 coldest cities in the United States and think, “boy, I bet those cities have a real urban heat island problem” – would you?

But for several of the cities on this list, that’s exactly what’s going on. Albany, NY, and Des Moines, IA – both in fairly northern regions of the United States – made the list of coldest cities, while still suffering from significant urban heat island problems.

Friendly reminder that – even in some of the coldest regions of the world – reflective surfaces can help them address these problems, and help cities become more resilient to climate change.

7 Actions for Cities to Seriously Address Climate Change

Cities are where more than half the world lives, and where all future population growth will occur. By many estimates, cities are already responsible for more than half of climate change. While Congress remains dysfunctional, cities are rapidly becoming the most interesting and innovative developers and adopters of programs to cut CO2 emissions. They increasingly are taking on the responsibility of achieving deep CO2 emission reductions that virtually all climate scientists tell us we must achieve.

I participated in the recent VERGE day-long City Summit, and was impressed by how much effort and innovation around climate change reduction is occurring in cities. More than 1,000 U.S. mayors, who represent some 60 million Americans, have signed on to the U.S. Conference of Mayors’ Climate Protection Agreement, committing to cut city-wide CO2 emissions below 1990 levels. Houston, Philadelphia and Los Angeles recently launched the Mayors’ Nation Climate Action Agenda (PDF), a joint commitment to an inter-city cap-and-trade program to reduce CO2 emissions by 80 percent by 2050.

For the most part, however, cities have not yet gotten serious about implementing substantial policies to cut CO2 emissions. Following are seven actions cities can and should take in order to reduce emissions by more than half while saving money.

1. Adopt cool roof, green roof and solar harvesting strategies

Half of city surfaces are roads, parking lots, sidewalks or roofs. These generally absorb over 75 percent of the sun’s energy, converting it into heat that increases urban temperature and global warming, both of which increase smog formation and energy bills. The low reflectivity of these surfaces imposes huge unnecessary social and environmental costs.

It is cost-effective today to double the reflectivity of most city roofs and paved areas. Through the work that Capital E is doing with Washington, D.C., the National Housing Trust, the American Institute of Architects and others, we have found that by adopting cool roofs, green roofs and solar PV on roofs, most cities dramatically can improve comfort and health while cutting energy costs.

Cool and green roofs and solar PV should be evaluated on a full costs and benefits basis — including health — to inform policies.

2. Integrate smart-building platforms with existing systems

City agencies commonly have different building energy management systems and a range of often incompatible energy using devices, controls and systems. Buildings — even LEED buildings — can be made to operate better if they are managed through a smart building platform that integrates with all existing systems, including building energy systems, controls and sensors, and uses near real-time data from these systems to optimize energy use and comfort.

A strategy such as ESCO 2.0 features integrated, near real-time, smart energy data, and controls and optimization to actively manage a portfolio of buildings. A recent NRDC study (PDF) of three efficient commercial buildings, including a newly commissioned LEED building, that adopted a smart-building optimization platform called AtSite cut energy use by 8 to 17 percent with almost no new equipment investment.

One advantage of an ESCO 2.0 strategy is that it allows a shift from expensive scheduled maintenance to maintenance triggered by near-real time equipment performance. Another benefit is improved comfort. This kind of open platform also allows virtually unlimited flexibility in adding in new equipment or applications.

3. Enter into long-term agreements to buy new renewable energy

Today a lot of cities, among other building owners, buy short-term (typically two-year) Renewable Energy Credits. These are in essence transferrable, inexpensive accounting claims for the environmental benefits associated with renewable energy. But in reality RECs are almost entirely from projects that are already completed (often many years earlier), and the RECs have little or no impact on driving new renewable energy investments.

To drive new renewable energy investments, cities should skip RECs and instead contract to buy renewable energy on terms long enough to actually allow new project financing. To do so, cities should enter into long-term purchase power agreements with renewable energy power developers to buy clean energy at fixed rates — typically below the rate they are currently paying.

This long-term purchase commitment means revenue certainty for the project developer, enabling equity and debt financing for project construction. Smaller cities can band together to do larger, joint PPAs for renewable energy, in turn bringing down the cost of clean energy.

These PPAs can be executed by almost any city today, would achieve real CO2 reductions and generally would cut the long-term cost of electricity. City government can invite in-city groups, such as schools and hospitals, to participate in city PPAs to enable even larger cost and environmental savings.

4. Insist that cities’ energy efficiency investments be counted in cap-and-trade programs

About half the U.S. population lives in states with cap-and trade programs (including California and members of the Regional Greenhouse Gas Initiative) that place a dollar value on CO2 as a way to encourage investments that cut CO2 emissions. But while large industries, corporations and utilities can participate, cities are excluded from these programs. This makes no sense.

A national initiative called CO2toEE seeks to allow energy efficiency investments by cities and other building owners to receive the value of the CO2 reductions that result from their energy efficiency investments. This initiative has broad and growing support from state and national real estate and energy organizations and NGO groups — and cities should join to push for this common-sense and important design change in carbon trading programs.

The value of the CO2 received by cities would offset a significant part of the capital cost of deeper energy efficiency investments, increasing the funding for deep energy efficiency investments.

By allowing city and building energy efficiency to participate, cap-and-trade markets also would become larger, deeper and more efficient, and would drive large additional investments into energy efficiency. This is essential if cities are to achieve deep reductions in their CO2 emissions.

5. Measure, count and reduce the CO2 embedded in cities’ buildings and roads

Most cities that count their CO2 emissions and invest in reducing CO2 still ignore the enormous volume of CO2 that results from constructing their buildings, roads and other infrastructure.

Cement production is responsible for about 6 percent of the world’s CO2 emissions. A recent review of California’s 500 mile high-speed train found that it would take about a decade of CO2 emissions reductions from rail trips replacing car, truck and plane trips to offset the CO2 emissions from the production of cement required to build the train’s infrastructure. And it can take an energy-efficient building six or eight years of operations to equal the CO2 emissions from the cement used in construction. In fact, the most recent release of the national green building design standard, LEED v4, awards points for reduction of embedded CO2.

What if, instead of generating CO2 emissions, cement sequestered CO2? What if cities measured their embedded CO2, and then used their infrastructure — roads, parking lots, sidewalks and their buildings — to sequester CO2?

6. Invest in new versions of ancient building products that can reduce or sequester CO2 in buildings

Wood sequesters CO2, and the recent development of advanced structural wood products such as cross-laminated timber allow 10 or 20 story buildings to be built of wood.

A much larger CO2 sequestration opportunity is low or negative carbon cement. Cement, first used by Mesopotamians and Romans, is also being reinvented. Cement produces almost a ton of CO2 per ton of cement (cement is made by burning limestone at over 2500 degrees.) Several companies produce low or negative carbon cement.

The most interesting of these companies is Blue Planet, which sequesters flue gas from power plants in cement, sand and aggregate (cement is combined with sand and aggregate to make concrete). Blue Planet can sequester up to 1,500 pounds of CO2 per ton of cement. In its current work at the DOE National Carbon Sequestration Center and in other partnerships, Blue Planet is targeting an 80-percent CO2 reduction from fossil fuel plants, such as natural-gas fired power plants. The process also sequesters other damaging pollutants, such as PM2.5, heavy metals and NOx.

7. Incorporate best-estimate CO2 costs into design and investment decisions

Even in places such as California that have active carbon markets, the market price for carbon is far below its real cost. Because climate change already imposes large costs, cities increasingly want to account for global-warming costs in their investment decisions.

A dozen federal agencies, including the Treasury Department and the Environmental Protection Agency, developed a rigorous cost analysis called the social cost of carbon (PDF). First released in 2010 and updated in 2013, it found the real cost of CO2 to be in the $40/ton range, with additional identified costs not included. Based on a Congressional request, the report and its methodology were extensively reviewed by the General Accounting Office, which a few months ago issued a report that entirely confirmed the social cost of carbon analysis and findings.

A good strategy — recently adopted by the Federal Green Building Advisory Committee which I chair — is to include the social cost of carbon in all construction and energy-related design decisions. In effect it is revenue neutral because it is used just to make better design decisions.

While this will take years to implement in federal agencies, cities can and should move rapidly to adopt this rigorous and conservative cost of carbon in their own design and investment decisions. This would allow better, more cost-effective investment and design decisions that reflect the real cost of climate change. (British Columbia’s adoption of a substantial cost of carbon helped achieve deeper CO2 reductions, lower overall taxes and faster economic growth than other Canadian provinces that did not adopt a carbon price.)

Enabled by organizations such as the Urban Sustainability Directors Network, C40 Cities and the Global Cool City Alliance, cities have become the most promising and important forum to drive deep CO2 reductions. Cities increasingly have the political will to get serious about climate change and to lead their countries to a very low-carbon future consistent with protecting the planet and future generations from the worst of climate change. The clock is ticking.

This article is based on a presentation Nov. 10 at the National Academy of Sciences/Institute of Medicine.

Disclosure: I work with several of the above companies and organizations as a board member/adviser/investor.

Greg Kats serves on the Board of the Global Cool Cities Alliance.

This article was originally posted on November 13, 2014 at GreenBiz.com. (http://www.greenbiz.com/article/7-actions-cities-seriously-address-climate-change)


On November 6th, I gave a talk at the annual gathering of the Northern California Chapter of the American Public Works Association. The talk was titled, “Keeping you Communities Cool: Tools for Reducing Urban Heat”. It started with an introduction to the growing problem of urban heat and the scientific fundamentals behind cool materials. Because the audience was composed primarily of representatives from municipal agencies, many of them focused on stormwater management and transportation, I focused largely on cool pavements, and only touched briefly on cool roofs and shade trees. The bulk of the presentation focused on the benefits that can be derived from large scale introduction of cool pavements and the range of pavement options that are available.

The audience was remarkably engaged and we were able to have a good discussion about the trade-offs between some of the different pavement options, the state of the science, and some of the challenges of advancing the use of cool pavements and shade trees when working in municipal public works departments. One example is that the public tends to like having black paved surfaces because it makes them feel as though their roads and parking lots are new and in good repair!

My presentation is available on the Knowledge Base:


Cool Roofs Are Cooling Homes in India

Climate change is driving up temperatures in cities around the world.  When things heat up, many of us simply reach for the thermostat and the air conditioner does its job.  In many parts of the world however, air conditioning isn’t an option and the rising temperatures mean homes become uninhabitable.   But there is a simple and affordable solution – a cool roof can bring down the temperature indoors by a few degrees, which is enough to allow people to sleep in their beds at night.

That’s where programs like the Cool Roof Project – through the Asian Cities Climate Change Resilience Network, and the Rockefeller Foundation – can help.  This program is installing cool roofs in Indore city, India, and residents are already getting relief from the urban heat.  From the Rockefeller Foundation

At Mamta Chouhan’s house, located in one of the 50 locations where cool roof technology has been implemented, a perceptible difference in indoor temperature is seen during high heat days.  The 200 families who have participated in this project have felt similar impacts as well.

Vijay Bhargava, a resident of Indore, reports that TARU came to him and others with an idea to reduce the temperature in their homes. “I didn’t believe it at first,” he admits, “but then they shared the details, including the potential benefits, and I changed my mind.  Afterwards, we felt a five or six degree change.  Incredible!”

He adds that he and his family couldn’t even sit upstairs in the summer before.  “Now, we can sit anywhere in the house, not feeling a difference whether we’re upstairs or downstairs.  It’s meant that we’ve been able to reduce our air conditioning usage substantially.”

They’re collecting data to document the many benefits of this program, and hope to convince local government, real estate developers and other interested parties to include cool roofs in future projects.   Stay tuned!

Quarter-hourly real time monitoring of urban temperatures from Space

Real time monitoring of the diurnal variations in the distribution of the land surface temperatures (LST) across a city is significant to a range of issues, including heat wave risk, energy demand and heat-related health issues. Geostationary satellites, such as Meteosat Second Generation- Spinning Enhanced Visible and Infrared Imager (MSG-SEVIRI) viewing Europe, Africa and a part of S. America, are the only remote sensing platforms that can offer continuous monitoring of LST distribution at quarter-hourly basis. The high temporal resolution of many meteorological geostationary satellites is unparalleled for the diurnal study of the Surface Urban Heat Island (SUHI) phenomenon, since it can reveal the most subtle changes. However, their coarse spatial resolution of 3-5 km has prohibited their extensive use for urban studies. The only way to exploit the dataset from this monitoring platform for urban applications is to employ computational methods for sharpening the data down to 1 km or better.

A system for real time and online monitoring of the thermal urban environment using geostationary satellite images is being developed at the Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing of the National Observatory of Athens (IAASARS/NOA) in Greece. The system comprises separate modules, namely: satellite image acquisition, cloud screening, and sharpening of LST. Satellite images are acquired from MSG-SEVIRI EUMETCast station installed at IAASARS/NOA. The cloud screening delineates the cloud-free pixels allowing the LST derivation to be applied only to clear sky thermal infrared radiances. Lastly, LST imagery is downscaled down to 1 km spatial resolution using Support Vector Regression Machines (SVM) and iterative gradient boosting.

The summer months of 2014 were the first operational ones: our system produced thousands of sharpened LST images every quarter-hour in real time. Our vision is to develop the system for all the cities with population greater than 1 million in the SEVIRI disk (117 cities in total). The system can be potentially used for heat-related health issues, energy demand applications, urban planning, Urban Heat Island studies and more.

A short video of what we do: http://youtu.be/pCMUHi7FJiY

Are you interested in collaborations? Let us know!

Dr. Iphigenia Keramitsoglou is a Senior Researcher at IAASARS/NOA and co-Leader of the Group on Earth Observations (GEO) Global Urban Observation and Information Task. She is member of the Program Management Board of BEYOND project that is partly financing this activity.

GCCA Executive Director Speaks at GreenBuild Conference

Thousands of people gathered in New Orleans, LA earlier this week for the annual Greenbuild conference, to share ideas, network, tour local green buildings and hear from many terrific speakers.  From the conference website:

Greenbuild is the world’s largest conference and expo dedicated to green building.  The green building community gathers to share ideals and mutual passion at Greenbuild, sparking a contagious buzz throughout the week.

When industry leaders, experts and frontline professionals dedicated to sustainable building in their everyday work come together, the result is a unique and palpable energy. Participants are invigorated and inspired.  They find themselves equipped to return to their jobs with a renewed sense of purpose.

GCCA Executive Director, Kurt Shickman spoke at this event about the many problems caused by the urban heat island effect, and the ways reflective surfaces can help bring relief to overheated city dwellers, reduce energy consumption, and reduce carbon emissions.  Take a look…

Urban Heat Island Turns Top Floor Apartments into Ovens

It doesn’t matter where you live – extreme urban heat is a major problem and it’s getting worse.   As the effects of climate change take hold, temperatures are steadily rising – this year is on track to be the hottest on record and there’s no relief in sight for city-dwellers.   Especially those in poorer neighborhoods.

This article from the South China Morning Post about a recent study paints a grim picture for people living in older buildings.   Their homes get hotter and they spend a higher percentage of their income struggling to keep cool.

Low-income dwellers living on the top floors of old tenement buildings have become the forgotten victims of the urban heat island effect, a green group has found.

The heat – trapped in bare, unpainted concrete – dissipates into households below turning flats into “ovens”.

“The rooftops of some of these old buildings can get so hot you can fry eggs on them,” said Dr William Yu Yuen-ping, chief executive at the World Green Organisation, the group that carried out the study.

One measurement at Mong Kok one afternoon measured a maximum rooftop temperature of 74.4 degrees.   The air temperature in the flat below rose to 36.8 degrees, five degrees higher than the 32 degree mean temperature recorded by the Observatory that day.

Yu urged the government and the Commission on Poverty’s Community Care Fund to help these households by offering subsidies for planting rooftop gardens or painting buildings in white to dissipate heat.

Rooftop temperatures of 74.4 degrees Celsius – that’s 165.2 degrees Fahrenheit by the way.  And inside the top floor apartments… over 98 degrees Fahrenheit.   This problem is universal and white roofs can help lower the temperature, reduce energy consumption and save lives.

Los Angeles White Roofs Building Code is Online

Speaking of useful resources…

Last December, the Los Angeles City Council updated the city’s building code – which required the installation of white roofs on commercial structures – to require the installation of white roofs on new and rebuilt residential structures.  The city has put all the documents and discussion on line in their docket – including the City Attorney’s report.

Since then, several other cities (Pasadena and Hermosa Beach, CA) have enacted similar updates.  We thought it might be useful for other cities to have access to the relevant documents and reports, so we’ve added information on Los Angeles to our ToolKit Knowledge Base, which you can find HERE.