green roof

Green Roofs Keep Urban Climates Cooler

By Thomas Landreth

Image of a green roof

Green roof

From conversations I’ve had with friends in construction: roofing is tough work. Steep angles make for dangerous conditions, metal roofing is remarkably sharp, and whatever material you work with, it’s guaranteed to be heavy.

During the summer, heat adds an almost unbearable element. This can be especially bad in metropolitan areas, where ambient temperatures combine with heat coming off numerous nearby roofs, pavement, and other elements to create an “urban heat island.”

EPA researchers and partners recently published findings in the Proceedings of the National Academy of Sciences showing how three types of roofing can help: “cool” (coated in a reflective material to eliminate heat buildup), green (vegetated), and hybrid (vegetated with reflective plants).  Hybrid roofs, which are a new concept and not yet available, would be constructed with light-colored plants that have higher reflectivity similar to cool roofs and also the advantages of green roofs, like water retention.

The authors found that any of these roofing options can have benefits by cooling urban heat islands. Thus, this helps to reduce the impacts of global climate change by cooling metropolitan regions.

Lead author Matei Georgescu, a sustainability scientist at Arizona State University, explains, “What we found for cool, green, and hybrid roofs is that they don’t just offset urban expansion—they can offset additional warming.”

Georgescu partnered with EPA scientists Philip E. Morefield, Britta G. Bierwagen, and Christopher P. Weaver, his co-authors on the study.

Through EPA’s Integrated Climate and Land Use Scenarios (ICLUS) project, researchers  had access to a wealth of modeled data focused on impacts from projected urban growth. Using these data, they explored the three methods of roofing designed to absorb less heat to compare and contrast benefits and trade-offs. What they discovered is that while all three  have positive environmental implications, green roofs have less heat-mitigating power than cool roofs (hybrid roofs cool at least as well as cool roofs alone), but cool roofs may mean that additional heating is needed during the winter in some areas.

Though roofing is a single component among major factors such as urban sprawl and carbon pollution, this study shows it can have an impact on reducing heat in large urban areas.

New roofing alternatives may offer an added component to innovative urban designs, new building styles and grid layouts created to offset urban heat islands. “Green cities” may not be a reality yet, but facets to such future cities are currently being considered and implemented. Interest in cooling down urban heat islands is growing and recently caught the attention of over 40 news outlets, including Popular Mechanics, Scientific American, Christian Science Monitor, USA Today, the LA Times, and several international newspapers.    

Although roof installation may not get any easier, green and cool roofs may soon make American’s urban hotspots cooler.

About the author: Until last week, Thomas Landreth was a student services contractor working with EPA’s Office of Research and Development. He recently accepted a new position with the American Association for the Advancement of Science (AAAS).

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Climate Change and Health: Lessons Learned from Older Americans

To continue the Agency’s efforts to expand the conversation on climate change, we are highlighting EPA climate change research with Science Matters articles. This post features research exploring the health effects of climate change and older Americans. 

Climate Change and Health: Lessons Learned from Older Americans
EPA researchers are exploring the links between climate change and health effects for older Americans. 

OldercouplestrollingClimate change is affecting a growing population of at-risk older Americans. Studies by EPA researchers and others find that seniors aged 65 and older are more vulnerable to hot temperatures and extreme weather events—effects which will become more frequent as the climate changes.

In a recent paper, “Climate Change and Older Americans: State of the Science” (Environ Health Perspect 121:15–22. 2013), EPA researchers reviewed the current “state of the science” about the links between climate change and health effects impacting older Americans.

The paper explores connections between what is expected to be an increase in the population of older Americans living in places relatively more affected by climate change. “Life expectancy has increased at the same time that we see a huge bubble of baby boomers headed into retirement. These demographic changes are happening even as the effects of climate change are becoming more widely recognized,” explains EPA economist and lead author Janet Gamble.

To assess the vulnerability of older Americans to climate change, the research team performed an extensive literature search.  From more than 400 citations identified, they selected nearly 100 papers to review that most closely addressed key terms describing characteristics of the older life stage; their vulnerability to climate-related impacts, and their overall health and well-being.

Older adults comprise 13% of the U.S. population today, but are expected to account for approximately 20% by 2040. They are also a diverse group, with differences in age, race/ethnicity, socioeconomic status, degree of community or family support, general health or pre-existing medical conditions, and disability. These differences ultimately determine the extent of older adults’ vulnerability to the impacts of climate change.

In addition, location matters.  “Older adults are retiring in areas, such as Florida, that experience a higher rate of extreme weather events,” notes Gamble, adding that more that 50% of older adults reside in only nine states, with Florida, California, New York, Texas, and Pennsylvania accounting for the top five.

Regions with higher levels of older adults, such as the five states mentioned above, are likely to be particularly at risk to changing precipitation patterns, tropical storms, flooding, and the urban heat island effect, a term describing the warming of urban areas relative to their rural surroundings due to the prevalence of buildings, roads, and other dark, heat-absorbing surfaces.

The report finds that older adults living in poverty or on fixed incomes are likely to experience greater exposure to some climate-related impacts, especially the effects of heat waves or hurricanes. Poverty is a primary contributor to social vulnerability, as financial status affects their ability to respond quickly and effectively. Older adults living in poverty can be more vulnerable to property damage and loss due to lack of insurance, limited personal finances, and poor credit worthiness.  In addition, older adults living in poverty may not have transportation to evacuate an area during an extreme weather event and may live in substandard housing, also increasing their risks.

The authors highlight a number of measures, called adaptations, that may address such vulnerability.

Such adaptations promote effective community responses to risks thought to be climate-related and may include: community support networks, subsidization of air conditioners, and community-based registries to help identify and reach those who require evacuation assistance. Similarly, planting trees or installing green roofs can reduce the urban heat island effect.

Identifying effective adaptation measures and outlining the best ways to implement them continue to be a challenge.Oldercoupletakecellphonepicture

When asked about next steps, Gamble states, “I think there is more work to be done in assessing the vulnerability of at-risk populations. As a first step, we need to communicate the climate risks experienced by older adults to decision makers, public health and safety officials, and caregivers and advocates of aging populations.  Also, in the near term, it may be possible to build on and adapt some of the response strategies developed for heat waves and hurricanes and apply them to the broader set of climate change impacts affecting older adults.”

By investigating the relationship between climate change stressors and vulnerability to at-risk life stages such as older Americans, EPA researchers are helping to inform communities and others so they can be better prepared to protect human health.

Learn More

Climate Change and Older Americans: State of the Science (Online abstract)

EPA Research: Climate Change and Health

Preparing for Extreme Heat

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Around the Water Cooler: Living in a Sustainable District

By Zoe Kaiser

I never carry an umbrella, but I do commute to work, walk many places instead of driving, and care about how my hair looks. Why? It’s a cultural thing; I am from Seattle. Born and raised in one of the cities that is most notorious for constant drizzle, carrying an umbrella is something a true Seattleite would never do. Since coming to DC, I have suffered the consequences as it has rained quite a bit. 

Since joining EPA as an intern, I’ve also learned that rain can bring more than just bad hair days. Stormwater runoff from rain can be a major concern for the environment.   

Stormwater can sweep motor oil, pesticides, and other pollutants into local waterways where it can harm nature (see our previous post that tells the story particularly well) and create unsafe environments for recreation such as swimming and fishing. 

The recently released Sustainable D.C. Plan proposes using sustainability solutions to address core challenges for water by 2023, including making 100% of District waterways fishable and swimmable and 75% of the city’s landscape able to capture rainwater for filtration or reuse. This is essential for continued health of waterways, and is achieved in multiple ways.  While this is an ambitious goal for any city, the plan outlines many ways in which the city can achieve a greener, healthier community. My home town of Seattle has already taken many strides to be more sustainable from municipal composting programs, to solar energy in homes and businesses, and green roofs on many colleges in the city. These programs and other initiatives have made Seattle a leader in sustainable living.

The District aims to install 2 million new square feet of green roofs around the city. Green roofs are pleasing to the eye and could be a great indicator of D.C.’s progress in meeting its sustainability goals. Through some modifications, most buildings can install a green roof with flowers, plants and other greenery. In addition, the plan proposes building 25 miles of green alleys. This “green infrastructure” adaptation would involve changing alleys from asphalt or concrete to a pervious surface, such as a polymer-based grass paver or porous asphalt.  

I would love to have a green roof or live on a street made from pervious pavement. And instead of giving in and buying an umbrella now, perhaps I’ll just wait to see how much my hair absorbs! After all, D.C. is focusing on stormwater runoff and I should be too.  Have you seen any sustainable infrastructure modifications in your community? Please share in the comments section below.

About the Author: Zoe Kaiser is the Science Communications Intern and is currently a Junior at Johns Hopkins University. When she’s not in the office or in class, she loves to read about ways we can all be more sustainable in our everyday lives.

Learn more!
Read about the Sustainable DC plan here:  http://sustainable.dc.gov/

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Surviving on this Island

I’ve often walked around Chicago in the peak of summer, only to feel the pavement underneath my feet feel as if it sizzling in the beating sun.   It’s hot.  I literally feel like a piece of frying bacon on the sidewalk sometimes.   It’s a heat island. 

A heat island is a built-up area which is consistently hotter than its surroundings, particularly in the summer.  The heat island effect is caused mostly by the difference between the generally dark surfaces of a city like roads and sidewalks and the vegetation it’s replaced. These dark surfaces absorb sunlight, heat up, and retain more heat than open space areas.  Add hot air from vehicle exhausts and industry, the temperature rises even more.

There is one place that I know of that is high above the pavement of the city streets and it’s still cool.  It’s the green roof on top of City Hall.  In 2001, it was completed and took this large underutilized space in the thick urban Chicago jungle and created an oasis of green living.  The 20,300 square foot City Hall rooftop garden has over 20,000 native plants that were installed as plugs of more than 150 varieties.  Although rainwater is collected and saved, a supplemental irrigation system aids in establishing the plants as well as provide supplemental water during extreme periods of drought.  Pretty neat, huh? 

I wondered about the inside of the building and so I asked a few members of the staff about their thoughts on the green roof.  Did it make a difference?  All agreed that it insulates the building, making it warmer in the winter and cooler in the summer.  They also noticed that when they walk out of the building, immediately there is a cool breeze surrounding the building before they step further out into the thick humidity of the day. 

If a green roof is helping change the heat island effects in one part of Chicago, think about what it could do if they were all over the country.  Communities can take a number of common-sense measures to reduce the effects of summertime heat islands.   You can help! 

To find out more, go to http://www.epa.gov/heatislands/index.htm

Yvonne Gonzalez is a SCEP intern with the Air and Radiation Division in Region 5. She is currently pursuing a dual graduate degree at DePaul University.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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Greening EPA's Seattle Office

A green roof has been installed on our downtown Seattle office building

A green roof has been installed on our downtown Seattle office building

By Bruce Duncan

The Region 10 Science Steering Council recently hosted our first “Science Café” to discuss how our Seattle office building is working toward LEED (Leadership in Energy and Environmental Design) certification as we undergo a major remodel. LEED is a third party certification program administered by the U.S. Green Building Council that focuses on the design, construction and operation of high performance green buildings.

I moderated the meeting and want to share some of the discussion. The first presentation focused on the building’s infrastructure (its green roof, pipes, and pumps) and participation in a private/public group committed to significantly reducing energy consumption by 2030.

Next, was a detailed look at the upcoming remodel of EPA space in the building and how we might get to a LEED “Platinum” rating. Presenters showed how the remodel is a unique opportunity to capture environmental benefits, energy efficiencies and cost savings. EPA is pursuing projects in:

  • sustainable site selection
  • water efficiencies
  • energy and atmosphere
  • materials and resources
  • indoor environmental quality
  • innovation and design process
  • regional priorities that further sustainability.

Each project generates points toward the LEED rating.

Our last discussion centered on what we can do in our individual spaces to be sustainable by recycling and reducing our use of resources.

Interesting information to me from the Q&A sessions included:

  • What is the cost to building management to register for LEED certification?

Approximately $10,000.

  • How is the return on investment working out for the building upgrade to LEED?

The payback horizon is reasonable for those components that do have a quantifiable return on investment. As we move forward, we would be comfortable with a 5 year payback horizon.

  • What are we doing to improve our office space that does not count toward LEED rating?

One example is the computer server room, which will be located to take advantage of cool outside air near windows.

What I liked most about our Science Cafe was seeing the linkage from my own office space and habits, to EPA’s space, to our building overall and how it sits within a self-led management community committed to sustainability.

Read more about EPA’s efforts to “green” our facilities.

About the author: Bruce Duncan is an Ecologist supporting risk assessments our Region 10 Office of Environmental Assessment. He is a member of the Region 10 Science Steering Council and has a long-standing interest in sustainability. Bruce also “walks the talk,” having installed solar panels on his Pacific Northwest home.

Editor’s Note: The opinions expressed in Greenversations are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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A Special Place to Sit 8 Days Each Fall

Historically related, but less well known than the Spring festival of Passover’s retelling of the Exodus, is the Fall festival of Sukkot (pronounced sooKOTE). Eight days long, it traditionally requires “dwelling” in small, crude, temporary huts, with roofs open to the elements and sky. (Because the roof of a sukkah is often made of wooden slats and greenery—for me, ivy and hemlock from my yard–it must have been the original green roof technology without, of course, the stormwater mitigation and energy conservation benefits we value today.) I typed dwelling in quotes because it’s become common, at least among many of my friends, to fulfill our dwelling obligation by having meals in a sukkah but not spending the nights.

There is, for me, an especially important environmental aspect of Sukkot, which is more than a commemoration of the biblical 40 years of wandering through the wilderness; it’s also a celebration of the fall harvest and, so, nature’s bounty, our impact on the environment (and on farm workers), and our sacred obligation (tikkun olam) to help fix what’s ailing the environment.

As I took about three hours last week to construct and decorate my sukkah—using wood originally cut many years ago and often replaced and reinforced following occasional storms that have blown it down—I thought about the eight days of moments I’d soon enjoy, whether alone or, better, with family and friends, looking through the roof and pondering the cosmos and our earthly place within it. What with the great weather this time of year, and a glass of wine, what could be better—more serene, more contemplative, more appreciative of nature, more challenging, more enjoyable?

How does your religion interacts with your thoughts about the environment and nature?

About the author: Larry Teller joined EPA’s Philadelphia office in its early months and has worked in environmental assessment, state and congressional liaison, enforcement, and communications. His 28 years with the U.S. Air Force, many as a reservist, gave him a different look at government service.

Editor’s Note: The opinions expressed in Greenversations are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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What Life is Like Working in a Green Building?

image of greenery with cityscape in the backgroundWhile this photo may appear to be that of a lush meadow in the foreground of a big city, it is actually a vegetated rooftop on a 9-story building in downtown Denver. When EPA Region 8’s office moved to a new “green” office building in Lower Downtown Denver, I did not know what to expect. I had never worked in a green building before. I really did not think it would be that different from a regular building. Was I wrong… Not only was the building very beautiful, it was the most comfortable building I have ever been in. From the lighting to the indoor air quality, I knew we were in a top quality and healthy working environment.

Our building is environmentally friendly and provides daily opportunities for us to practice stewardship. Some features of our building that help us decrease our impact include:

  • Extensive use of daylight to reduce need for artificial light
  • A vegetated green roof to control storm water and decrease urban heat island effect
  • Waterless urinals and low-flow plumbing fixtures to decrease water use
  • High recycled content materials throughout the building
  • Proximity to public transit

However, it is not enough to simply build a green building; a big part of the equation is how the building is operated and the behavior of the occupants. Region 8’s Environmental Management System helps us improve our performance by quantifying and managing the impacts of our operations (e.g., electricity and water use, waste generation and transportation) and taking actions to reduce those impacts.

The green design, construction, operation and maintenance of 1595 Wynkoop, combined with close attention to our collective actions, help EPA in our efforts to practice what we preach.

Working in a green building is the only way to work in my mind. I have more energy throughout the day which I attribute to the environmentally healthy aspects of our building. I have the pleasure of knowing my work day has also been less of an impact to the environment. You can find out more, hear an audio tour and see lots of pictures of our green building at: http://www.epa.gov/region8/building/index.html

About the author: Wendy Dew has been with EPA for 11 years and is the Environmental Education and Outreach Coordinator for Region 8.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

What Life is Like Working in a Green Building?

While this photo may appear to be that of a lush meadow in the foreground of a big city, it is actually a vegetated rooftop on a 9-story building in downtown Denver. When EPA Region 8’s office moved to a new “green” office building in Lower Downtown Denver, I did not know what to expect. I had never worked in a green building before. I really did not think it would be that different from a regular building. Was I wrong… Not only was the building very beautiful, it was the most comfortable building I have ever been in. From the lighting to the indoor air quality, I knew we were in a top quality and healthy working environment.

Our building is environmentally friendly and provides daily opportunities for us to practice environmental stewardship. Some features of 1595 Wynkoop Street our building that help us decrease our environmental impact include:

  • Extensive use of daylight to reduce need for artificial light
  • A vegetated green roof to control storm water and decrease urban heat island effect
  • Waterless urinals and low-flow plumbing fixtures to decrease water use
  • High recycled content materials throughout the building help preserve resources
  • A daytime cleaning crew that uses less toxic cleaning products and allows our building to shut down at time???
  • Proximity to public transit reduces the impact of employee’s commute
  • Redeveloping a site that was an eyesore and underutilized???

But however, it is not enough to simply build a green building; a big part of the equation is how the building is operated and the behavior of the occupants. Region 8’s Environmental Management System helps us improve our environmental performance by quantifying and managing the impacts of our operations (e.g., electricity and water use, waste generation and transportation, to name a few) and taking actions to reduce those impacts.

As a newly constructed building, 1595 received a Gold rating in the Leadership for Energy and Environmental Design (LEED) program. Now, Region 8 is working toward a Gold rating in LEED for Existing Buildings: Operations and Maintenance (LEED EBOM) to ensure that our building is performing to the standards it was designed to meet (though this was put on the back burner for a while so need to check with Kate).

The green design, construction, operation and maintenance of 1595 Wynkoop, combined with close attention to our collective actions, help EPA Region 8 EPA in our efforts to practice what we preach.

I feel very lucky to be able to work in a green building. We have a lovely green roof we can sit near and have our lunch or conduct a meeting. We have convenient recycling and bike storage. Our building sits right on the 16th Street mall which has a free shuttle we can ride to numerous public transportation options and great lunch spots!

I also enjoy seeing all the tour groups that come through our building. Almost 10,000 people have visited us since we opened. I especially love to see the kids viewing a green building for the very first time, teaching them how a plastic bottle gets recycled into fiber and then turned into products like carpet (??) then challenged to make their school as green as possible when they leave.

Working in a green building is the only way to work in my mind. I can see better with natural day lighting. I have clean air to breathe. I have more energy throughout the day which I attribute to the environmentally healthy aspects of our building. I have the pleasure of knowing my work day has also been less of an impact to the environment. You can find out more, hear an audio tour and see lots of pictures of our green building.

About the author: Wendy Dew has been with EPA for 11 years and is the Environmental Education and Outreach Coordinator for Region 8.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.