Heat Island Effect
Welcome to EPA's Urban Heat Island Newsroom. The Newsroom provides current news and links to news releases related to urban heat island impacts, mitigation strategies, and community initiatives. To help keep you up to date, you may also wish to sign up for EPA's Urban Heat Island Newsletter. Older stories can be found in the Newsroom Archive.
- University of Minnesota Researchers Examine Heat Island Effect (July 2, 2014) - Ongoing University of Minnesota research using 200 temperature sensors placed around the Twin Cities has found that Minneapolis and St. Paul have about a 3-degree temperature difference compared with surrounding areas.
- Yale Researchers Examine Primary Causes of Urban Heat Island Effect (July 9, 2014) - In an analysis of 65 cities across North America, researchers found that variation in how efficiently urban areas release heat back into the lower atmosphere—through the process of convection—is the dominant factor in the daytime UHI effect.
- Savannah Tree Foundation Study Shows Savannah Tree Canopy Decreasing (July 15, 2014) - Chatham County, GA has lost the equivalent of three football fields of tree canopy every day, on average, over the last 15 years, according to an ongoing analysis commissioned by the Savannah Tree Foundation.
- Study Examines Urban Heat Island’s Effect on Tree Mortality in the Southeast (July 24, 2014) - New research from North Carolina State University shows that urban heat islands are slowly killing red maples in the southeastern United States. One factor is that researchers have found warmer temperatures increase the number of young produced by the gloomy scale insect—a significant tree pest—by 300%, which in turn leads to 200 times more adult gloomy scales on urban trees.
- Milwaukee Public Library Installs Green Roof (July 25, 2014) – A 33,000 square foot green roof on the Milwaukee Public Library has prevented 2.82 million gallons of rainwater from entering the city's storm sewer system since it was installed.
- University of Iowa Deploys Green Roof at Medical Campus (July 28, 2014) - The Pappajohn Biomedical Discovery Building will feature a multi-level green roof totaling 6,440 square feet of plants.
- Ann Arbor City Council Approves Urban Forestry Plan (June 3, 2014) - The city’s first comprehensive plan for managing Ann Arbor’s urban forest has been given approval by the city council.
- Virginia Tech Researchers Examine Benefits of Green Roofs on Stormwater Runoff (June 10, 2014) – The Virginia Tech research team found that the deeper the vegetation, the better the roofs controlled stormwater runoff. Overall, green roofs retained about 50% of the stormwater, compared with about 6% for conventional flat roofs.
- American Council for an Energy-Efficient Economy Releases Urban Heat Island Mitigation Survey (June 17, 2014) - This report profiles the causes, impacts, strategies, and social and institutional context of city action on heat island mitigation in the sampled cities. It found that heat waves and other disasters are motivating cities to implement heat-mitigation strategies.
- Georgia Tech Researcher Finds that Louisville Requires More Trees to Counteract Urban Heat Island Effect (June 18, 2014) – The urban heat island effect in Louisville ranked highest among 50 of the country’s largest metropolitan areas, according to a study by Brian Stone, a professor of city and regional planning at Georgia Tech. The study found that Louisville has room to add about 1.2 million trees.
- Too Hot to Handle (June 23, 2014) - The New York Times’ health correspondent Jane Brody reports on the risks to human health from extreme heat events, both today and under future climate change scenarios.
- Study Finds that Green Roofs Can Reduce Urban Heat Island Effect (June 25, 2014) – Princeton University researchers tested their model on the Baltimore-Washington metropolitan area during a four-day heat wave and found that a reduction of surface temperature of 1 °C could be achieved if 30% of all roofs in the area were green or cool roofs.
- U.S. Department of Agriculture Announces Urban and Community Forestry Challenge Grants (June 26, 2014) - The grants provide funding that will help enhance urban forest stewardship, support new employment opportunities, and help build resilience in the face of a changing climate.
- AC Trees Announces Urban Forestry Grants to 12 Communities (June 30, 2014) - Funding will support local grassroots organizations to plant, maintain, and harvest fruit and nut trees in 12 cities across the country from California to New Hampshire.
- Arizona State University Releases Study on the Impact of Air Conditioners on Urban Heat Island Effect (May 15, 2014) – Arizona State University researchers have found that excess heat from air conditioners running during the night leads to higher outside temperatures, worsening the urban heat island effect and increasing cooling demands.
- Louisville Awards $115,700 Tree Canopy Assessment Contract (May 7, 2014) – Louisville city officials awarded a contract worth $115,700 to a firm to complete a tree canopy assessment by the end of the year. The city will use the assessment to set priorities for tree planting to address urban heat, stormwater management, and other concerns.
- American University Researcher Studies Impact of Green Roofs on Pollution (May 14, 2014) – An American University researcher is studying the ability of green roofs to prevent pollutants from entering the Anacostia and Potomac rivers.
- Butte, Montana Establishes $2 Million Tree Planting Program (May 24, 2014) – A $2 million tree planting project in Butte aims to establish species diversification, stabilize the soil, and prevent soil erosion on Butte Hill, the site of former copper mines.
- University of Maryland Sustainability Fund Awards $50,000 in Green Roof Grants (April 3, 2014) – The University of Maryland Sustainability Fund awarded $50,000 to the university’s facilities management department for projects that either include a green roof or a rainwater harvesting system.
- People Who Have Trees Are More Likely to Participate in a Tree-Planting Program, Study Finds (April 15, 2014) – A new study indicates that homeowners with street trees, and ones living in older homes, are more likely to participate in a tree-planting program.
- White Roofs are More Economic than Green Roofs, Study Finds (April 22, 2014) – A new report from Lawrence Berkeley National Laboratory found that white roofs are three times more effective at countering climate change than green roofs.
- Menomonie, Wisconsin, Urban Forestry Board Announces Urban Forestry Program (April 9, 2014) – The Menomonie Urban Forestry Board announced the Trees for Everyone Everywhere (TREE) initiative, a cost-sharing program for tree planting in the city.
- New York Department of Environmental Conservation Awards $797,437 in Urban Forestry Grants (April 26, 2014) – The New York Department of Environmental Conservation awarded $797,437 in urban forestry grants to 34 cities, towns, villages, and non-profits.
- Survey Finds Green Roof Square Footage Increased 10 Percent from 2012 (April 24, 2014) – Green Roofs for Healthy Cities released its Annual Green Roof Industry Survey, which finds that the North American green roof industry grew by 10 percent in 2013 over 2012.
- Nashville Music City Center Completed with Green Roof (April 23, 2014) – The Nashville Music City Center achieved LEED Gold certification, in part for its 175,000 square foot green roof and 360,000 gallon rainwater harvesting and recycling system.
- New Orleans Sustainable Village Complete, Along with Green Roofing (April 21, 2014) – Global Green USA completed its Holy Cross Project in the Lower Ninth Ward of New Orleans, which contains green roofs and bioswales to reduce the urban heat island effect and improve permeability.
- New York City Offers $6 Million in Green Project Grants (March 4, 2014) – The New York City Department of Environmental Protection is encouraging community groups, non-profits, and property owners to apply for $6 million in new funding for green infrastructure projects.
- Seattle Department of Transportation Plants 500 Trees (March 31, 2014) – The Seattle Department of Transportation planted approximately 500 trees in West Seattle and Rainier Beach.
- TD Bank and Arbor Day Foundation Announce 2014 TD Green Streets Grant Recipients (March 4, 2014) – Ten municipalities were each awarded $20,000 to support innovation in urban forestry.
- New Haven Urban Resources Initiative Receives $30,000 Grant to Promote Benefits of Trees (March 13, 2013) – The Connecticut Department of Energy and Environmental Protection has awarded $30,000 to New Haven’s Urban Forestry Initiative to improve outreach strategies and increase citizen involvement in urban forestry programs that enhance aesthetics and reduce cooling costs.
- Oklahoma Arbor Week Initiative Seeks to Plant Trees to Reduce Urban Pollution (March 20, 2014) – The City of Edmond, Oklahoma celebrated Oklahoma Arbor Week by planting trees throughout the city for enhanced aesthetics and air quality, erosion prevention, and energy savings.
- Austin Creates Urban Forest Master Plan (March 26, 2014) – The City of Austin, Texas adopted an Urban Forest Master Plan with guidelines that city departments should address, including protecting trees during development, creating tree canopy cover goals, and recycling green waste.
- Iowa Museum Installs Green Roof (March 25, 2014) – The Curatorial Center at the Museum of Danish America in Elk Horn, Iowa will install a green roof using a $50,000 grant from the Iowa West Foundation. The roof will be covered in prairie grasses, goldenrod, yellow cornflower, and other plants native to the area.
- Institute for Environmental & Spatial Analysis Researcher Publishes Results of Climate Study (February 5, 2014) – Researchers at the Lewis F. Rogers Institute for Environmental & Spatial Analysis at the University of North Georgia introduced a new framework and terminology for thinking about and studying urbanization and its effects on the climate system.
- Houston Urban Forestry Event Focuses on Benefits of Trees (February 11, 2014) – Northwest Harris County, Texas, gained more than 1,000 new trees during the Houston Area Urban Forestry Council's 2014 Tree Planting Competition. The contest is designed to help educate people on proper ways to plant trees and on the benefits of urban forestry for the community.
- Heat Island Reduction Strategies Could Curb Warming from Urban Growth, Study Finds (February 12, 2014) – Researchers examined six “megapolitan” regions in California, Arizona, Texas, Florida, the Midwest, and the Mid-Atlantic to predict how much they would warm under different urban growth and development scenarios. According to the study, urban areas can offset that warming through strategies such as slowing their expansion, painting roofs white to reflect heat, or planting rooftop vegetation to cool the air.
- Indiana Department of Natural Resources Announces Urban Forestry Funding (February 19, 2014) – The Indiana Department of Natural Resources’ Division of Forestry has awarded $118,343 in federal funds to 12 cities, towns, and non-profits in Indiana for urban forestry projects, including tree inventory and analysis for management planning, new tree plantings, and education and awareness campaigns.
- Keeping Urban Trees Healthy During Drought (February 24, 2014) – Watering and caring for urban trees during drought is important. Shaded landscapes retain soil moisture and keep the city cool, and when it does rain, a mature tree can capture thousands of gallons of rainwater in its canopy and root zone, sinking that rain into the aquifer instead of allowing it to run off into storm drains.