How to Manage the Risk?

Extreme heat events, which are projected to increase in frequency and severity in New York City over the next few decades, can have significant consequences for at-risk populations and infrastructure – a situation that calls for implementation of more comprehensive risk management strategies.

Some of the most important near-term strategies include informing at-risk populations about health risks, taking measures to insulate infrastructure from increased stress during heat waves, keeping internal building temperatures cool, and reducing the urban heat island effect.

Before a heat wave strikes, the public – especially at-risk populations – must be made aware of the dangers of prolonged exposure to extreme heat, the types of people that are most at risk and why, and the practical measures people can take to protect themselves, their families, and their neighbors.

Experiences of severe heat waves in other cities have led New York City to enhance its own risk management strategies.

New York City has several initiatives to mitigate the risks to residents, especially vulnerable populations, before heat waves occur:

Lessons Learned: Major Heat Waves that Informed NYC Outreach Strategies

Two of the most significant heat waves in recent memory occurred in Chicago in 1995 and across much of Europe in 2003:

  • Chicago’s historic heat wave of July 1995 lasted for two weeks. The heat index peaked at nearly 120°F, claiming over 700 lives.
  • In 2003, Europe’s heat wave was even more dramatic and widespread, affecting France, Portugal, the Netherlands, Spain, Italy, Germany, Switzerland, the United Kingdom, and Ireland. This extreme weather event lasted most of the summer, with heat peaking throughout the first half of August. The use of air conditioning in homes and businesses across Europe is much less common than in the United States – a factor that likely contributed to the very severe impact of the heat wave. Estimates of heat-related deaths range from 50,000 to 70,000, with nearly 15,000 deaths in France alone.

The dramatic social impact of the Chicago and European heat waves exposed the vulnerabilities of certain population groups, especially older adults living without air conditioning, who were the majority of the victims.

The ten-day heat wave in 2006 was one of New York City’s worst extreme heat events in the past two decades. This event prompted New York City to expand its Heat Emergency Plan to increase outreach to residents who are at greater risk from heat-related illness, the various organizations and providers that serve these residents, and to emphasize the importance of air conditioning in preventing heat illnesses. New York City also carried out heat-health analysis that led to lower National Weather Service (NWS) thresholds for heat advisories in New York City.

An important part of New York City’s heat-hazard outreach is to encourage New Yorkers to check on at-risk family, friends, and neighbors during periods of extreme heat and to share life-saving information about heat risks and how to stay cool.

  • Prevention: As part of the Cool Neighborhoods NYC initiative, coordinated by the Mayor’s Office of Resiliency, New York City Department of Health and Mental Hygiene (DOHMH) works with different partners to promote heat resiliency. One DOHMH activity provides support to homecare agencies to train Home Health Aides about the health risks of extreme heat and how to help their clients stay safe during such an event. Another is DOHMH’s launch of “Be A Buddy,” a community-led pilot project to develop and implement strategies to promote social cohesion and increase community resilience for extreme heat, power outages, and other extreme weather.
  • Outreach: The City conducts outreach to the general public and their partners -- healthcare providers, community groups, faith groups, and service-agencies -- by providing advice on how to mitigate risk from extreme heat. Outreach includes press releases, social media posts, in-person training and workshops, and direct electronic communications to partners. During heat emergencies, the City encourages its partners and the public to check on clients, neighbors, family, and friends who may be at increased risk for heat-related illness during periods of hot weather.
  • Publications: The Ready New York website “Beat the Heat,” published by NYCEM supplies important safety tips and other information online and in print. DOHMH also supplies information to the public and to health care providers about the health impacts of heat and heat illness prevention.
  • Financial assistance: Cooling assistance is available to New York City residents who are at high risk of heat hazards. Financial assistance is offered through the Home Energy Assistance Program (HEAP), a federally funded program administered by the NYS Office of Temporary and Disability Assistance with applications for New York City residents processed through the New York City Department of Social Services. People may qualify for financial aid to purchase and install an air conditioner, if they meet HEAP’s income criteria and have documentation of a medical condition that is exacerbated by need.

During heat waves, New York City and its partners take the following actions to keep vulnerable populations and the general public safe:

  • Advisories: NYCEM closely monitors NWS heat advisories, excessive heat watches and warnings. When conditions warrant, NYCEM activates New York City's Heat Emergency Plan, which was developed jointly with the NWS, DOHMH, and other partners.
  • Alerts: During heat emergencies, alerts and safety tips are disseminated to the public through Notify NYC and to organizations serving vulnerable populations through the Advance Warning System. Health care providers receive alerts through the Health Alert Network and other DOHMH channels.
  • Cooling Centers: During heat emergencies, cooling centers are opened at designated locations, such as community centers, senior centers, and public libraries, to provide access to air-conditioned spaces to anyone who needs to escape the heat. Studies show that spending as few as two hours a day in an air-conditioned space can significantly reduce a person’s risk from heat-related illnesses. During the summer of 2018, New York City had over 500 air-conditioned spaces available.
  • Outreach to homeless populations: During extreme heat events, outreach teams redouble round-the-clock outreach and engagement efforts citywide. Street homeless outreach teams are trained on heat stroke and other health and safety issues and reminded of criteria to enact removals under State law during weather emergencies (individuals must be at risk themselves or posing a risk to themselves or others).  No one who is homeless and seeking shelter in New York City during an extreme heat event will be denied. Should any New Yorker see an individual who appears to be homeless and in need out in the heat, please call 311 and an outreach team will be dispatched to offer assistance.
  • Support during outages: During outages, utility providers such as Con Edison and PSEG will conduct outreach to customers who have registered as being dependent on Life Support Equipment.

Government agencies and private sector entities pursue a wide range of short- and long-term strategies to manage risks associated with heat-related hazards to infrastructure. Some long-term initiatives have the critical short-term benefit of reducing demand on the power grid and the associated risk of power outages.

Energy Systems

Utilities employ “supply-side” strategies to reinforce strain on the system and continue operations during extreme heat events:

  • System reinforcements provide alternate or additional infrastructure capacity to minimize the risk of disruption due to heat – for example, by increasing the number of power supply feeders, upgrading to higher capacity cables, installing or upgrading more distribution transformers, building new substations, and redistributing electric loads among substations.
  • Improving system reliability safeguards system components so that they are operational and available for service. This includes inspecting and maintaining equipment, repairing components, and implementing improvements such as redesigning circuits to minimize the number of customers affected, rebalancing demand across supply feeders, installing automated switches and monitoring equipment, as well as performing mobile scanning of city streets to reduce the risk of contact voltage.
  • Operational readiness involves measures to prepare system operations for summer conditions and respond to events as they occur. This includes conducting engineering analyses and studies to assess system conditions, implementing protective steps such as voltage reduction, instituting the Incident Command Structure (ICS) for forecasted peak heat days, activating special resource teams such as cooling and event triage teams, conducting staff training and exercises on how to handle extreme heat scenarios, and confirming that power generators have adequate capacity.
  • Pre-position back-up generators if a system is potentially vulnerable due to projected demand.

The city’s primary utility providers, Con Edison and PSEG, are strengthening their power sources and energy infrastructure by making utility systems more flexible and by diversifying energy sources to minimize impacts of extreme weather events. Utilities also employ “demand-side” strategies to manage load on the system and continue operations during extreme heat events:

  • Utility demand response and energy efficiency programs are short and long term strategies that offer financial incentives to customers to help reduce overall energy consumption and peak demand on hot days. Con Edison runs aggressive demand-response programs in which commercial, industrial, and residential customers can enroll voluntarily. When demand for electricity soars, Con Edison pays those customers who temporarily reduce their consumption of electricity upon request. Con Edison’s energy efficiency programs offer customers rebates when customer install new energy efficiency and control equipment.
  • Installing Advanced Metering Infrastructure (AMI). AMI, or “smart meters,” will assist customers in controlling energy use and demand as well as allow Con Edison to know immediately where customers are experiencing power outages and better coordinate restoration.
  • Con Edison is conducting a climate change vulnerability study, which includes an examination of how changing climate conditions will impact their system and what mitigation measures may be needed.

Transportation Systems

Transportation systems can be protected from hazards associated with periods of extreme heat with measures such as:

  • Equipment upgrades to rail systems, which involves replacing or retrofitting system components, such as tracks, wires, signals, and switches.
  • Retrofitting roads and bridges with heat-resistant materials to prevent cracking and buckling from thermal expansion.

The Metropolitan Transportation Authority (MTA) has invested in ways to protect its systems and equipment from heat-related damage, such as implementing new redundancy measures and making structural improvements to trains, railroad tracks, and buses.

New York City’s Department of Transportation (DOT) is studying the use of permeable pavements for its roads and bridges. The greatest advantage of deploying these types of pavements is to reduce the impacts of heavy precipitation and snowmelt; however, use of these materials, which remain cooler than typical roadway surfaces during summer months, may also reduce the damage to road surfaces during from heat waves.

Several long-term strategies in New York City aim to increase the energy efficiency of buildings, and lower indoor air temperatures – steps that help to reduce energy consumption over the long-term. These strategies with New York City’s built environment can reduce the risk of power outages and reduce reliance on other short-term strategies, such as utility demand-response programs.

New York City’s Construction Code has been improved to promote energy-efficient, cooler roofs. The current Construction Code promotes sustainable building design by allowing the construction of green roofs previous code required building owners to obtain special permission for this type of construction. The Construction Code also requires that building owners use heat-reflective coverings on any roof having a less-than-25-percent slope. The 2012 Zone Green Text Amendment changed New York City’s zoning provisions to exclude green roofs from height limitations.

Many buildings have been designed and constructed to achieve performance standards that exceed the minimum required in New York City's Construction Codes, and to keep internal building temperatures low through energy efficiency. These high-performance buildings use advanced designs and construction techniques -- windows that keep cool air from escaping during summer, rigorous air sealing, and extensive insulation.

The Mayor’s Office released One City: Built to Last, a plan to reduce greenhouse gas emissions 80 percent by 2050, followed by New York City’s Roadmap to 80 X 50, which proposes reducing building energy use by improving the efficiency of building systems, equipment, and operations, and by dramatically expanding on-site renewable energy generation.

Existing buildings in New York City can benefit from retrofits so that their energy consumption is lower during periods of extreme heat. Several types of energy-efficient improvements can be made:

  • Proper sealing and insulation keep buildings cooler by stopping cooled air from leaking out. Owners of existing buildings can caulk and seal doors and windows that leak air, and caulk and seal air leaks in walls, floors, or ceilings where openings exist for plumbing, ducts, or electrical wiring. The proper insulation of walls and attics also help, because insulation slows the transfer of heat into a building's interior.
  • High-performance materials, such as multiple-paned windows with reflective coatings, can be used to insulate buildings from extreme heat and keep cool air from escaping. Energy-efficiency retrofits, such as higher-efficiency mechanical systems and smart sensors, can reduce energy demand, decreasing the strain on the electric grid.
  • Application of white, reflective surfaces to rooftops, which reduces cooling costs, cuts energy usage, lowers greenhouse gas emissions, and extends the lifespan of the roof. The coating used on the rooftops is highly reflective and quickly releases heat, which results in reduced absorption of solar heat leading to cooler buildings. Temperatures within the building can be reduced by up to 30 percent. Aside from the benefits for the coated buildings, white rooftops reduce temperature in the surrounding areas and combat the urban heat island effect. City law requires the application of reflective coatings on new roofs and those that are undergoing significant repairs or replacement.
NYC CoolRoofs, a partnership between NYC Department of Small Business Services, Mayor’s Office of Resiliency, and Sustainable South Bronx, promotes and facilitate the cooling of New York City's rooftops by installing a reflective coating to dark roofs. The program provides free cool roof installations to nonprofits, affordable housing, and select cooperatively-owned housing. Privately-owned buildings can receive installations at minimal cost. The initiative also provides local job-seekers with training and paid work experience coating rooftops. The following map shows the locations of cool roofs installed by the program and reported by building owners from 2009 – 2019.  Since the program’s inception over 10 million square feet of Cool Roofs have been installed in NYC. As part of Cool Neighborhoods initiative, since 2017, the City targets outreach and prioritizes installations in the most heat-vulnerable neighborhoods using the Heat Vulnerability Index.

NYC CoolRoofs 2009 - 2019

The New York City Department of Housing Preservation and Development (HPD) has developed New York City Greenhouse, a program to help building owners retrofit with higher-performance materials, which would reduce the amount of energy and water used in building operations. This program provides tax credits, rebates, and incentives that promote energy efficiency, and offers tips on how to lower energy bills.

Utilities contribute to this effort by offering demand-reduction programs -- incentives to commercial and industrial building owners to permanently reduce their energy consumption. Con Edison offers a number of energy efficiency tools to encourage residential, small business, multifamily building, and commercial/industrial customers to reduce energy consumption.

Actions taken by New York City to reduce the amount of greenhouse gas emissions serve the long-term goal of slowing the rate of climate change. Taking action to increase the energy efficiency of New York City buildings has a more immediate impact -- to avoid power outages during periods of extended heat and reduce building electricity costs.

NYC Cool Roofs Program

NYC Cool Roofs Program

Source: DOB-Samantha Modell

NYC Green Roofs

NYC Green Roofs

Source: NYC Parks

In June 2017, the Mayor’s Office launched the Cool Neighborhoods NYC initiative to protect communities from extreme heat events and also from rising average temperatures due to climate change. The mitigation and adaptation efforts of this $106 million initiative include targeting the NYC CoolRoofs program, and strategic tree planting in heat-vulnerable neighborhoods, partnering with community-based organizations to launch “buddy systems” in three boroughs, training home health aides, community health workers, and health and weather reporters, and monitoring temperatures in neighborhoods that are most at risk to adverse health impacts during heat waves.

Environmental risk management strategies focus on increasing New York City’s vegetative cover and creating cooler building roofs to help lower air temperatures in neighborhoods and to reduce the urban heat-island effect.

Natural Cover and Green Areas

Certain features of New York City’s natural environment can partially offset the impact of extreme heat upon different neighborhoods. The urban heat-island effect is directly tied to a neighborhood’s ratio of ground covered by natural vegetation to that covered by asphalt and other artificially built, impervious surfaces. Trees and vegetation naturally cool the surrounding air by releasing moisture and absorbing carbon dioxide from the atmosphere; by contrast, many built surfaces trap heat and keep the surrounding environment warmer. Planting trees and vegetation along streets and in open spaces serves as ecological infrastructure in New York City and can significantly reduce local air temperatures. Replacing concrete, asphalt, or even grassy surfaces with trees can reduce the local air temperature by several degrees. Green roofs – roofs with vegetation planted on them – can reduce both outdoor and indoor air temperatures. MillionTreesNYC is a public-private initiative that was launched in 2007 by New York Restoration Project and the New York City Department of Parks and Recreation with a goal of planting and caring for one million new trees citywide by 2015. The City planted 70 percent of these trees in parks, along streets, and in other public spaces. The remainder were planted by homeowners, businesses, and community organizations. As of November 24, 2016, the 1-million-trees goal was reached.

Bioswale in Queens by NYC Greenstreets

Bioswale in Queens by NYC Greenstreets

The City's Green Infrastructure Program, led by New York City’s Department of Environmental Protection, promotes a variety of sustainable green infrastructure practices, including green roofs, rain gardens, and right-of-way bioswales on City-owned property such as streets, sidewalks, schools, and public housing. Although this program’s goal is primarily to reduce the impacts of stormwater runoff and combined sewer overflows, its green-roof and other strategies also help to reduce the urban heat island effect in New York City.

Extreme Heat - Bibliography