Urban Heat Islands and Mitigation Strategies LIHEAP Webinar May 25, 2016 Victoria Ludwig, U.S. EPA Heat Island Reduction Program

What is the Heat Island Effect? Micro-scale temperature differences between urban and rural areas Urban areas can be 2 – 22 º F higher than rural areas Air and surface temperatures Day and night temperatures Complex due to…. Surface vs. air temperature Diurnal and seasonal variability Dependent on synoptic conditions Geographic vs. topographic causation Importance of other weather variables (humidity, etc)

What Causes the Heat Island to Form? Reduced vegetation Materials used to build urban infrastructure Urban geometry Generation of waste heat (e.g., air conditioners, engines)

Climate Change and Heat Islands Nationwide, unusually hot summer days (highs) have become more common over the last few decades The occurrence of unusually hot summer nights (lows) has increased at an even faster rate. This trend indicates less “cooling off” at night Climate models project increases in the frequency, intensity, and duration of extreme heat events in the decades ahead Heat islands amplify extreme heat events

Heat Island Impacts Increased energy use 5 – 10 % of summertime electricity demand cools heat islands 1.5 – 2.0% E demand  for every 1 ºF  in the summer Longer peak periods; pressure on E grid; brownouts, blackouts Air quality and carbon pollution Increased greenhouse emissions (climate change) Increased air pollution Increased ground-level ozone formation Water quality Warmer water runoff = ecological shock in waterways Increased water runoff = more pollutants in waterways 5 5

Extreme Heat and Public Health Heat is a serious danger: Respiratory problems Heat cramps, heat exhaustion Non-fatal heat stroke/sun stroke Heat-related mortality Extreme heat is often the most deadly weather-related event in a given year (compared to hurricanes, lightning, tornadoes, earthquakes, etc.). Overall, nearly 8,000 Americans suffered heat-related deaths since 1979 Peaked in 2006, a year that was the second-hottest year on record in the U.S. Extreme heat contributed to the deaths of about 8,000 people since 1979 Older adults and young children are physiologically sensitive to extreme heat. People living in poverty are vulnerable due to substandard housing and lack of access to air-conditioning. Note that 8.7% of the U.S. population of older adults lived below the official poverty level in 2011. 6

Who is the Most Vulnerable? Reducing heat islands helps protect public health…now and in the future Lower temperatures provide direct benefits to vulnerable populations: Older adults, Young children, People with lower incomes Outdoor workers People with compromised health Indirect health benefits include better air quality due to reduced ozone formation More than 9% of U.S. children and nearly 8% of older adults aged 65-75 currently have asthma. Exposure to ozone can exacerbate asthma. 7

Urban Design Can Reduce Vulnerability Incorporating heat island mitigation measures in built environment considerations offers an opportunity to improve public health AND MORE: Trees and Vegetation: Better air quality, carbon storage Green Roofs: Stormwater benefits, improved human comfort Cool Roofs: Increased grid reliability, energy savings Cool Pavements: Lower air temperatures, public safety benefits Smart Growth: More vegetation, less paved areas Infrastructure projects often have long lifetimes; if their design can be influenced today to incorporate heat island mitigation measures, they’ll provide health and other benefits for years to come. ACEEE (American council for an energy-efficient economy) and GCCA survey of 26 cities in North America (Vancouver and Toronto) found that each city had at least one mitigation strategy and 25 had more than one. Most popular is tree canopy.

Mitigation Strategy: Trees & Vegetation Most U.S. communities have opportunities to increase the use of trees and vegetation in their land cover to reap multiple benefits. Strategically planting trees maximizes energy savings. Buildings Parking lots Streets

Mitigation Strategy: Green Roofs Decrease heat island impacts by shading roof surfaces and through evapotranspiration Can save energy both in the summer and winter; energy savings depend on local conditions and building circumstances Can be installed on a wide range of buildings, from industrial facilities to private residences

Mitigation Strategy: Cool Roofs Cool roofing products are made of highly reflective materials that can remain about 50 to 60°F cooler than traditional materials during peak summer weather.

Implementation through Voluntary Efforts Demonstration Projects Incentive Programs Urban Forestry and Community Tree Planting Programs Weatherization Outreach and Education Awards

Implementation through Policy Efforts Procurement Resolutions Tree and Landscape Ordinances Comprehensive Plans and Design Guidelines Zoning Codes Green Building Programs and Standards Building Codes Air Quality Requirements

Opportunities and Strategies to Consider Work with utilities and public utility commissions Collaborate with state and local government environmental agencies Promote energy savings benefits to developers and landlords Develop education materials in cooperation with community action groups Talk with other state governments that have implemented heat island reduction strategies

EPA’s Heat Island Program

Program Overview Mission The EPA Heat Island Reduction Program works to increase the number of programs and policies that include heat island reduction measures to create comfortable and sustainable communities. Heat Island Community Local and state policymakers/program designers Academia/researchers Other federal agencies Non-profit organizations Industry 16

Heat Island Program Resources Website: Basic information on heat island topics, calendar of events, heat island newsroom, science corner and more Examples: Database of info on more than 75 local and state initiatives to reduce heat islands and achieve related benefits Compendium of Strategies: Reducing Urban Heat Islands, provides scientific background, mitigation strategies, case studies, and links to other resources Heat Island Basics Trees and Vegetation Green Roofs Webcasts: Cover topics such as local/regional urban heat island case studies, new scientific findings, and specific mitigation strategies Newsletter Cool Roofs Cool Pavements Heat Island Reduction Activities

Heat Island Newsletter Sign-Up: Contact Information Victoria Ludwig U.S. Environmental Protection Agency State and Local Climate and Energy Program ludwig.victoria@epa.gov Website: https://www.epa.gov/heat-islands Heat Island Newsletter Sign-Up: https://www.epa.gov/heat-islands/forms/heat-island-newsletter-signup