policy briefs on natural gas by Jessica Wright, BU URBAN Graduate Student

CAMBRIDGE CITY COUNCIL Quinton Y. Zondervan City Councillor MEMORANDUM To: Cambridge City Council From: Quinton Y. Zondervan, City Councillor Date: September 10, 2020 Subject: Policy briefs on natural gas by Jessica Wright, BU URBAN Graduate Student Dear Colleagues: The attached one-pager and three policy briefs were prepared by Jessica Wright, a participating student in the Boston University Graduate Program in Urban Biogeoscience and Environmental Health (“BU URBAN​”). Jessica’s research at BU has focused heavily on natural gas energy - specifically how gas leaks affect our urban canopy and research into transitions off of natural gas. This summer, as part of the URBAN program, she completed an internship with my office, researching and writing the attached policy briefs on the public health impacts of natural gas, the job market impacts of natural gas, and the climate change impacts of transitioning away from natural gas as an energy source for buildings in Cambridge. I hope you find them helpful and informative in our ongoing climate and energy policy efforts. Sincerely, Councillor Zondervan CITY HALL, CAMBRIDGE, MASSACHUSETTS 02139 (6​1​7) 349​-​4280 ​FAX: ​(617) ​349​-​4287 ​TTY​/T​DD​: ​(6​1​7) ​349-4242 EMAIL: ckelley​@​cambridgema.gov

Electrification & A Move Off of Natural Gas in Cambridge, MA - ​Fact Sheet An energy transition to electricity and a move off of natural gas will help put Cambridge, MA on track to reach carbon neutrality by 2050. The motivations for moving off of natural gas are outlined below and include the public health and safety, job market, and climate change implications of natural gas. Public Health and Natural Gas: Natural gas energy poses a threat to public health both by diminishing indoor air quality and damaging street trees that provide ecosystem services beneficial to human health. ● Indoor air quality in gas-serviced homes and businesses is degraded by combustion byproducts released by pilot light and gas stove burner ignitions. Combustion byproducts are harmful chemicals proven to increase asthma exacerbations (asthma attacks of coughing, wheezing, and shortness of breath), increase risk of respiratory infections, and have been linked to nausea, headaches, and fatigue. ● Outdoor air quality is impacted by leaking natural gas infrastructure, as leaks and odorant from the aging pipes pollute degrade outdoor air. Gas leaks are linked to street tree damage and death, which significantly reduces their ecosystem services, including cleaning the air, providing shade, reducing the urban heat island effect, absorbing carbon dioxide, and encouraging recreational activity. Additionally, gas leaks inhibit the development of Cambridge’s urban forest master plan. Job Creation and Natural Gas: While the job market implications of electrification are challenging to quantify, the state of the science is encouraging of a multitude of jobs developing from a just energy transition plan: ● Clean energy jobs are numerous and growing as more demand for renewable energy develops. Solar and wind installation jobs are projected as two of the three most rapidly growing job markets in the country this coming decade. ● Ensuring a just transition for legacy fossil fuel and union workers will require complex planning. Including these workers and energy stakeholders throughout the planning and implementation processes of energy transition will be crucial to successfully address community needs. Prioritizing and educating low-income and environmental justice communities throughout the energy transition will ensure a just transition for all Cambridge residents. ● Providing security, funding, and retraining opportunities for legacy workers and new employees of the clean energy economy will help facilitate further support for an energy transition. Climate Change and Natural Gas: The climate change impacts of natural gas can no longer be ignored as Cambridge strives to lower carbon emissions, achieve robust climate goals, and grow their urban canopy. ● Leaking and aging natural gas distribution infrastructure corrodes and releases un-combusted natural gas, primarily methane, into the atmosphere contributing a significant source of greenhouse gas emissions and exacerbating climate change effects in the city. ● Leaks damage urban vegetation and street trees. Methane from leaks infiltrate street tree soil pits and push oxygen out, leading to root damage and tree death, damaging the existing tree canopy. *This one page document serves as a fact sheet. More details and bibliographical information can be found in the attached policy memos. 2

Public Health Impacts of Natural Gas - Policy Memo 1. Introduction: This policy memo is presented to the City Council of Cambridge, Massachusetts to inform decisions regarding a transition away from natural gas infrastructure in new construction buildings in the city. This memo will convey the state of the science of natural gas infrastructure and its public health and safety impacts on communities serviced by this energy type. A review of the science on public health and natural gas energy would be incomplete without noting the public health and safety impacts associated with hydraulic fracturing (fracking), the sourcing of natural gas. Fracking has become increasingly common in residential areas and has led to an increase in cardiovascular disease in populations near fracking sites, as well as significantly degraded air quality. , Cambridge is not located near a fracking site 1 2 but the health impacts throughout the natural gas lifecycle are significant, for example in Pennsylvania, Virginia. However, it is important to remember that our gas habits contribute significantly to public health issues in states close by. In the Marcellus Shale Region, located throughout western New York, Pennsylvania, and Ohio, there is a considerable amount of natural gas fracking. Research has shown that the chemicals used in fracking can damage the lungs, liver, kidneys, blood, and brains of people living nearby. While these pollutants are more common in areas of heavy fracking, there is emerging research 3 suggesting that some of these chemicals, some of which are carcinogens, may find their way downstream to the distribution network of the Greater Boston Area. Below, the public health impacts of natural gas 4 energy in residential households and municipalities like Cambridge is reviewed. 2. Research Question & Methodology The goal of the following policy memo is to provide scientific evidence in support of building electrification with a focus on protecting the public health and safety of Cambridge residents, both current and future. In addition to protecting the health and well-being of residents, electrifying new construction buildings will help Cambridge stay on track to becoming carbon neutral by 2050. Data to inform this policy brief was compiled from published peer-reviewed literature. A keyword search was completed using a variety of peer-review journal databases, such as Web of Science and Science Direct, as well as citations collected from the author’s 4 years of research in the field of natural gas energy. Keywords and papers were selected for their focus on the public health impacts of methane and combustion byproducts associated with natural gas energy. Additional data was collected through publicly available databases, including the location of known gas leaks currently reported in Cambridge as of the summer of 2020. 3. Key Findings Natural gas extraction and distribution has detrimental effects on both indoor and ambient air quality, which has direct impacts on public health. Natural gas generation relies heavily on combustion processes, 5 which release particulate matter and harmful gases, such as nitrogen oxides, sulfur dioxide, volatile 1 McKenzie et al. 2019. 2 Mac Kinnon et al. 2018. 3 Finkel & Law, 2011. 4 Woolhouse, 2018. 5 Mac Kinnon et al. 2018 3

organic compounds (VOCs), and carbon monoxide. Additionally, there are significant greenhouse gas emissions associated with natural gas generation that contribute to global warming and can cause damage to urban vegetation including the tree canopy. Promoting a robust urban tree canopy is important for 6 public health because trees in urban areas help to mitigate the urban heat island effect, lowering temperatures and providing shade while diminishing energy consumption, and contributing to the community’s well-being. 7 Building electrification has the potential to significantly decrease the greenhouse gas emissions from the city, reducing the climate change impacts associated with elevated levels of carbon dioxide and methane emissions. Methane is a greenhouse gas and a product of natural gas energy, however, there is little to no 8 research available regarding the direct impacts of methane on human health. Narrowing the scope to the public health consequences of natural gas in Cambridge, MA brings attention to two distinct public health concerns: the danger of combustion byproducts in homes with natural gas powered appliances, and the loss of beneficial public health ecosystem services like vegetative cooling, as climate change impacts are intensified in urban areas. , 9 10 3.1 Natural gas and combustion byproducts The most significant public health threat from natural gas energy occurs in homes serviced by natural gas powered appliances, including gas stoves, gas boilers (for home heating and hot water) and clothes dryers. Gas stoves are perhaps the most common and significant threat to residents because of the 11 on-site combustion reaction that happens at the burner when the stove is turned on. These pollutants are referred to as combustion byproducts and are caused by an incomplete combustion reaction. Combustion 12 byproducts include carbon monoxide, nitrogen dioxide, and particulate matter. Carbon monoxide is a colorless, odorless gas that can cause headaches, dizziness, and nausea. Nitrogen dioxide, another combustion byproduct can cause irritation in the eyes, nose, and throat, and in high concentrations can lead to an increased risk of respiratory infections. Particulate matter released during combustion can cause irritation in the lungs, damage to lung tissue if inhaled, and can lead to an increased risk of cancer. Lastly, incomplete combustion reactions can create water vapor, which can increase the humidity in a home, creating an environment for mold or dust mites. 13 Combustion byproducts from gas-powered appliances are a serious threat to human health and serious concerns about outdated and improper use of gas-powered appliances have emerged. A recent report published out of Australia found that replacing gas stoves in all homes with newer gas models or electric appliances and encouraging the use of proper ventilation hoods could lower asthma prevalence from indoor air pollutants nearly 10%. Proper ventilation and newer gas stoves, without a pilot light, have 14 been shown to help reduce the amount of combustion byproducts from gas stoves and help negate the 6 Hoeks, 1972. 7 City of Cambridge, 2020. 8 Tarroja et al. 2018. 9 Schollaert et al. 2020. 10 Salmond et al. 2016. 11 EPA, 2017. 12 ​Id. 13 ​Id. 14 Knibbs et al. 2018. 4

effects on gas-powered appliances on indoor air quality. Newer gas stoves and the use of a ventilation 15 hood when cooking can significantly reduce one’s exposure to combustion byproducts but these best practices are not always practical in every person’s home environment, especially for renters who do not have control over what type of appliances are in the unit. 16 There are underlying themes of environmental justice issues surrounding gas leaks and their impact on public health. Homeowners have a clear advantage as they have control over their fuel for heating/cooling and cooking. Renters can struggle with dictating their fuel type, although even among renters, there is a divide, as wealthier renters have more options and control over what type of infrastructure they will choose to live with. This disparity is one example of the disproportionate effects an energy transition can have on communities. Low-income communities and communities of color have historically been marginalized and disadvantaged when it comes to environmental stewardship and sustainable living and the energy transition case is no exception. Energy transition, if not handled properly, will negatively affect disadvantaged communities by exacerbating prevalent energy insecurity and issues of environmental racism. 17 3.2 Natural gas and vegetation loss Additional concerns about natural gas and public health are broader but equally important. Aging natural gas distribution infrastructure is springing leaks and from these leaks, uncombusted methane, a highly potent greenhouse gas, escapes into the urban atmosphere. This gas can also escape into street tree pits 18 and damage urban vegetation. A robust urban canopy has many public health benefits that are depleted when trees die or are removed due to damage from a gas leak. Massachusetts has a significant problem 19 with leaking gas infrastructure because over 11% of the pipeline distribution network in the state is made of leak-prone pipe material, like cast iron, compared to only 0.9% of leak-prone pipes across the country where older infrastructure has been replaced. Urban vegetation is associated with many public health 20 benefits including, improvement to air quality and associated respiratory outcomes, cooling temperatures in urban areas and reducing the urban heat island effect, improvement of physical and mental health through the promotion of recreational activity, and increased perceptions of personal safety. , A recent study in Chelsea, MA demonstrated that unhealthy or dying street trees were 30x 21 22 more likely to have elevated methane in their soils from a nearby gas leak than healthy street trees. 23 As Cambridge is working to improve their urban forest, considering the effects of gas leaks on street trees is of the utmost importance. Cambridge has developed a comprehensive Urban Forest Master Plan with the aim of protecting and promoting a robust, healthy, and sustainable urban canopy. The benefits of 24 15 ​Id. 16 Lunden et al. 2015. 17 Carley & Konisky, 2020. 18 Schollaert et al. 2020. 19 Nowak et al. 2013. 20 PHMSA, 2018. 21 Salmond et al. 2016. 22 Kuo et al. 1998. 23 Schollaert et al. 2020. 24 City of Cambridge, 2020. 5

such an urban canopy cannot be overlooked from both an environmental and a public health perspective. As highlighted by the study in Chelsea, MA from above, gas leaks pose a significant threat to street trees and can seriously degrade the urban canopy over time. Promoting a robust urban canopy can also help to 25 alleviate environmental and public health stressors, not only related to gas leaks but issues of air pollution and the urban heat island effect, in low-income environmental justice communities. To successfully reach the goals outlined in the Urban Forest Master Plan and to provide street trees for the most dire communities, Cambridge will be forced to address the issues of aging gas infrastructure lying under the street. 4. Recommendations / Next Steps Encouraging building electrification will prepare the City of Cambridge to reach its goals of carbon neutrality by 2050 and reduce the public health impacts of natural gas energy. Improving the indoor air quality of Cambridge residents, homeowners, business workers, and renters alike, can be achieved by switching from natural gas to electric appliances and heating. Incorporating electric infrastructure in new construction buildings from the start of construction will save health effects, time, and money down the road as Cambridge looks towards a clean energy future. Additionally, aging natural gas infrastructure will continue to leak and spew uncombusted gas, primarily methane, into the atmosphere contributing to the greenhouse gas emissions of the city and damaging urban vegetation and street trees. In order to maintain Cambridge’s urban canopy and the countless public health services provided by these street trees, reducing the mortality of these trees due to leaking gas infrastructure will be key. Electrifying new construction buildings is a logical place to start because there will be no additional reliance on the aged natural gas system moving forward. Beginning a climate forward development plan for the city, and creating jobs in the process, will help the city not only achieve its climate action goals but improve the health and well-being of its residents. 25 Schollaert et al. 2020. 6

References: Public Health Impacts of Natural Gas Carley, S., D.M. Konisky. 2020. The justice and equity implications of the clean energy transition. Nature Energy 5:569-577. City of Cambridge. 2020. Urban forest master plan. Public Works Initiatives. Last updated: February 2020. URL: ​https://www.cambridgema.gov/Departments/PublicWorks/Initiatives/UrbanForestMasterPlan accessed: September 8, 2020. Environmental Protection Agency. 2017. EPA Report - Sources of combustion byproducts: An introduction to indoor air quality. Last updated: February 22, 2017. URL: https://www.epa.gov/indoor-air-quality-iaq/sources-combustion-products-introduction-indoor-air-quality accessed: July 6, 2020. Finkel, M.L., A. Law. 2011. The rush to drill for natural gas: a public health cautionary tale. American Journal of Public Health 101(5):784-785. Hoeks, J. 1972. Changes in the composition of soil air near leaks in natural gas mains. ​Soil Science​ 1: 46-54. Knibbs, L.D., S. Woldeyohannes, G.B. Marks, C.T. Cowie. 2018. Damp housing, gas stoves, and the burden of childhood asthma in Australia. Medical Journal of Australia​ ​208(7). Kuo F.E., M. Bacaicoa, W.C. Sullivan. 1998. Transforming Inner-City Landscapes: Trees, Sense of Safety, and Preference. Environment and Behavior 30(1):28-59. Lunden, M.M., W.W. Delp, B.C. Singer. 2015. Capture efficiency of cooking-related fine and ultrafine particles by residential exhaust hoods. Indoor Air 25:45-58. Mac Kinnon, M.A., J. Brouwer, S. Samuelson. 2018. The role of natural gas and its infrastructure in mitigating greenhouse gas emissions, improving regional air quality, and renewable resource integration. Progress in Energy and Combustion Science​ ​64:62-92. McKenzie, L.M., J. Crooks, J.L. Peel, B.D. Blair, S. Brindley, W.B. Allshouse, S. Malin, J.L. Adgate. 2019. Relationships between indicators of cardiovascular disease and intensity of oil and natural gas activity in Northeastern Colorado. Environmental Research​ ​170:56-64. Nowak, D.J., S. Hirabayashi, A. Bodine, R. Hoehn. 2013. Modeled PM​2.5​ removal by trees in ten U.S. cities and associated health effects. Environmental Pollution 178:395-402. PHMSA. 2018. Pipeline replacement updates: cast and wrought iron inventories. U.S. Department of transportation pipeline and hazardous materials safety administration. Last updated: March 17, 2020. URL: 7

https://www.phmsa.dot.gov/data-and-statistics/pipeline-replacement/cast-and-wrought-iron-inventory accessed: August 27, 2020. Salmond, J.A., M. Tadaki, S. Vardoulakis, K. Arbuthnott, A. Coutts, M. Demuzere, K.N. Dirks, C. Heaviside, S. Lim, H. Macintyre, R.N. McInnes, B.W. Wheeler. 2016. Health and climate related ecosystem services provided by street trees in the urban environment. Environmental Health 15:S36. Schollaert, C., R.C. Ackley, A. DeSantis, E. Polka, M.K. Scammell. 2020. Natural gas leaks and tree death: A first-look case-control study of urban trees in Chelsea, MA USA. Environmental Pollution 263:114464. Tarroja, B., F. Chiang, A. AghaKouchak, S. Samuelsen, S.V. Raghavan, M. Wei, K. Sun, T. Hong. 2018. Translating climate change and heating system electrification impacts on building energy use to future greenhouse gas emissions and electric grid capacity requirements in California. Applied Energy 225:522-534 Woolhouse, M. 2018. The problem with cooking with (fracked) natural gas. BU Today. Last updated: March 20, 2018. URL: ​http://www.bu.edu/articles/2018/the-problem-with-cooking-with-fracked-gas/ accessed: September 8, 2020. 8

Job Market Impacts of Natural Gas - Policy Memo 1. Introduction: This policy memo is presented to the City Council of Cambridge, Massachusetts to help inform decisions regarding natural gas infrastructure in new construction buildings in the city. This memo will convey the job market possibilities from electrification and a clean energy transition in Cambridge and highlight the opportunities for job creation. Investing in natural gas energy in any new construction building will commit the City of Cambridge to further reliance on fossil fuels and further delay the city from reaching their climate action goals. In order to reach carbon neutrality by 2050, any building with natural gas will need to be transitioned to electric energy therefore encouraging electrification from the onset will expedite the city’s climate agenda. Protecting current gas workers and providing proper training and job security will be crucial in implementing electrification that services all concerned stakeholders. Additionally, to ensure a just transition for all communities, incorporating a commitment to job training and economic development support for those likely to be negatively impacted by an energy transition is key. 2. Research Question & Methodology The goal of the following policy memo is to convey the job market growth opportunities of building electrification in Cambridge. Reducing reliance on natural gas and promoting electrification throughout the city’s built environment would diminish greenhouse gas emissions associated with fossil fuel energy and push the city in the direction of carbon neutrality by 2050. Data to inform this policy brief was 26 compiled from environmental economic research, interviews with industry professionals, and a review of the published peer-reviewed literature. A keyword search was completed using a variety of peer-review journal databases, such as Web of Science and Science Direct, as well as citations collected from the author’s 4 years of research in the field of natural gas energy. Keywords and papers were selected for their focus on the politics and economic impacts of electrification and energy transition at the municipal level. Additional data was collected through publicly available databases. 3. Key Findings A transition to electrification and a clean energy economy is challenging to envision because of the variety of jobs that could be created as an outcome. An energy transition at the municipal level could be associated with dramatic job loss and an increase in unemployment. However, research has shown that a just energy transition can occur that maintains well-paying jobs, continues to provide for workers and their families, and promotes a healthy and sustainable energy future that is beneficial for all. The key findings from this research included two main takeaways: 1) how to incorporate and partner with the current gas infrastructure work force and related stakeholders in creating and implementing an energy transition plan that works for everyone, and 2) how to retrain workers and create new jobs to build and manage electrified infrastructure. 26 Cameron & van der Zwaan, 2015. 9

However, before diving into the literature of how an energy transition off of natural gas could take shape, it is important to review the state of the science on energy equality and just transition from areas around the world in the midst of transitioning their energy supply. Commonly, when imagining stakeholders who would be ill-affected by an energy transition, legacy workers from the fossil fuel industry come to mind. While those legacy workers would be adversely affected, it is important to realize that energy transition can also affect low-income communities and communities of color by worsening issues of energy insecurity and failing to educate and engage these disadvantaged groups in the transition process. 27 Scholars recognize that research on how to address these disparities is generally under-developed but for stakeholders and decision makers planning energy transitions, incorporating these disadvantaged communities will be integral in making any energy transition plan equitable. A piece published in 28 Nature argues that decision makers at the forefront of energy transition policies need to, work to redistribute welfare so as to avoid undue burden on any specific population and provide sufficient energy services to all, and… provide an adequate safety net for all populations, especially those most marginalized or burdened. 29 Incorporating these themes of a just energy transition is important when considering the job market possibilities in a Cambridge energy transition plan. 3.1 Coordinating an energy transition plan In partnership with the Natural Resources Defense Council (NRDC), a study out of the University of California highlighted the importance of protecting gas workers in a transition off of natural gas energy. 30 Important to remember when considering an electrification plan for the City of Cambridge is that such a transition does not occur overnight, meaning that for some current gas workers their job requirements will not change. Gas infrastructure projects will still occur and home service calls will require expert repair. However, maintaining the gas infrastructure during a phase of electrification will not require the full force of the gas workers that exist today, meaning some workers will face a transition in their career. A major concern for governments considering an energy transition or electrification plan is backlash from displaced gas workers. Therefore, a robust municipal plan to transition off of gas must be created in collaboration with gas workers. This will not only ease the concerns of the gas workers but ensure that a transition plan will provide the job security and economic benefits workers deserve. Key findings out of a report conducted in California, a state considering a gas ban and push towards electrification, found the following components to be essential to a comprehensive transition plan: 1. Establishment of a buyout program that could cover the costs of retirement systems for older workers 2. Establishment of a committee that could address how to best manage a shrinking gas workforce, while still safely maintaining any existing gas infrastructure throughout the transition period 3. Wage protection for transitioning workers 27 Healy & Barry, 2017. 28 ​Oppenheim, 2016. 29 Carley & Konisky, 2020. 30 Borgeson, 2019. 10

4. Provide funding and training/retraining for gas workers looking to transition to clean energy or electrification positions. 31 Prioritizing communication with gas workers throughout the planning and implementation of an electrification and gas transition plan is crucial for maintaining job security and incorporating the existing skilled workforce into a clean energy workforce. In addition to engaging with gas workers throughout 32 the planning phase, stakeholder groups such as residents can help develop a transition plan tailored to tbe communities’ specific needs. A recent study in Michigan found that when citizens and other stakeholders were involved in the planning process, they were more likely to perceive the positive benefits of energy transition, in this case wind turbine installation, than communities not at all included in the planning process. 33 3.2 Job creation in the transition stage A major component of electrification and energy transition at the municipal level will be creating jobs and retraining utility workers, often unionized labor, to provide well-paying career opportunities. 34 Researchers and non-profits are working to develop energy transition plans that not only serve the planet but also the work force required for such robust implementation. One such organization, based in Cambridge, MA, HEET (Home Energy Efficiency Team) has been researching the feasibility of a GeoMircoDistrict project. The GeoMicroDistrict would replace aging natural gas distribution 35 infrastructure with ground-source heat pumps that could service a small group of homes and businesses in a micro-district. Installation of the ground-source heat pumps may need specialized skills but all maintenance could easily be handled by the existing gas workers. Geothermal infrastructure carries water, not gas, under and through city streets to deliver heating and cooling services so a switch from natural gas to water maintenance would not only require minimal training but also promote a healthier and safer work environment.​11​ 36 Research from around the world suggests that a energy transition and shift towards renewable and more efficient low-carbon energy will lead to employment opportunities, ranging from manufacturing, construction, and installation to fuel extraction, supply, and transmission. The U.S. Bureau of Labor 37 Statistics recently reported that solar photovoltaic installers (51%) and wind turbine service technicians (61%) will be two of the three fastest growing occupations in the country in the coming decade, trailed only by nurse practitioners at 52% . 38 To address concerns about achieving energy efficiency and transitions to renewable energy throughout marginalized communities, various programs from municipalities are developing. Some examples include Colorado’s community solar program that reserved 5% of all projects for low-income residents, 31 Gridworks, 2019. 32 Bayulgen, 2020. 33 Mills et al. 2019. 34 ​BuroHappold Engineering, HEET 35 ​Id. 36 ​Id. 37 Carley & Konisky, 2020. 38 US Bureau of Labor Statistics, 2020. 11

Community Energy Scotland which engages and educates affected communities during the community energy project development phase, and the community programs run by the Inclusive Financing for Energy Savings program which aims to provide financing and host sessions for community members and utilities to build demand for energy efficiency and/or renewable energy investments for their communities. , , 39 40 41 4. Recommendations / Next Steps While the job market implications of a clean energy transition take multiple forms, it is crucial to realize that a clean energy economy enables significant job creation, both directly and indirectly, and may produce more jobs per unit of installed capacity than fossil fuel based energy. Additionally, in a report 42 published by Environmental Entrepreneurs (E2), nationwide clean energy jobs outnumbered fossil fuel based jobs nearly 3:1 at the end of 2018. These numbers are encouraging and demonstrate the job 43 creation possibilities brought forward by a just transition to clean energy. However, at the local scale, there are real and significant fears brought to light by gas workers and unions concerned about their futures were gas energy to be phased out. Therefore, incorporating these parties in the decision making process and ensuring security, retraining, and funding opportunities throughout the transition will be crucial to success. Implementing clean energy alternatives that utilize the existing skills of the gas workforce, such as the GeoMircoDistrict heating and cooling plan, will lower costs and time associated with retraining and could provide for healthier working conditions. Additionally, ensuring an 44 equitable and just energy transition across low-income and communities of color by engaging and educating these communities throughout the planning and implementation processes will be crucial to provide a healthier and more energy efficient city for all residents. 39 CO Energy Office, 2020. 40 Bomberg & McEwen, 2012. 41 Carley & Konisky, 2020. 42 Cameron & van der Zwaan, 2015. 43 E2, 2019. 44 BuroHappold Engineering, HEET 12

References: Job Market Impacts of Natural Gas Bayulgen, O. 2020. Localizing the energy transition: Town-level political and socio-economic drivers of clean energy in the United States. Energy Research & Social Science 62:101376. Bomberg, E., N. McEwen. 2012. Mobilizing community energy. Energy Policy 51:435-444. Borgeson, M. 2019. Protecting workers and communities requires gas planning. Natural Resources Defense Council. Last updated: September 19, 2019. URL: https://www.nrdc.org/experts/merrian-borgeson/protecting-workers-and-communities-requires-gas-planni ng​ accessed: September 3, 2020. BuroHappold Engineering. Geo Mirco District Feasibility Study. HEET MA. URL: https://heetma.org/wp-content/uploads/2019/11/HEET-BH-GeoMicroDistrict-Final-Report-v2.pdf accessed: September 3, 2020. Cameron, L., B. van der Zwaan. 2015. Employment factors for wind and solar energy technologies: A literature review. Renewable and Sustainable Energy Reviews 45:160-172. Carley, S., D.M. Konisky. 2020. The justice and equity implications of the clean energy transition. Nature Energy. Last updated: June 12, 2020. URL: ​https://www.nature.com/articles/s4[phone removed]-6 accessed: September 3, 2020. Colorado Energy Office. 2020. Community Solar. Last updated: 2020. URL: https://energyoffice.colorado.gov/community-solar​ accessed: September 8, 2020. E2. 2019. Clean Jobs America 2019. E2. Last updated: March 13, 2019. URL: https://e2.org/reports/clean-jobs-america-2019/​ accessed: September 3, 2020. Gridworks. 2019. California’s Gas System in Transition. Last updated: September, 2019. URL: https://gridworks.org/wp-content/uploads/2019/09/CA_Gas_System_in_Transition.pdf​ accessed: September 3, 2020. Healy, N., J. Barry. 2017. Politicizing energy justice and energy system transitions: Fossil fuel development and a “just transition”. Energy Policy 108:451-459. Mills S., D. Bessette, H. Smith. 2019. Exploring landowners post-construction changes in perceptions of wind energy in Michigan. Land Use Policy 82:754-762. Oppenheim, J. 2016. The United States regulatory compact and energy poverty. Energy Resources & Social Science. 18:96-108. 13

United States Bureau of Labor Statistics. 2020. Occupational Outlook Handbook. Fastest Growing Occupations. Last updated: September 1, 2020. ​https://www.bls.gov/ooh/fastest-growing.htm​ accessed September 8, 2020. 14

Climate Change Impacts of Natural Gas - Policy Memo 1. Introduction This policy memo is presented to the City Council of Cambridge, Massachusetts to help inform decisions regarding natural gas infrastructure in new construction buildings in the city. This memo will convey the state of the science of natural gas infrastructure and highlight how incorporating natural gas energy into new construction buildings will have negative environmental consequences for decades to come. Investing in natural gas energy in any new construction building will commit the City of Cambridge to further reliance on fossil fuels and further delay the city from reaching their climate action goals. Natural gas energy has potential to contribute to climate change across its lifecycle, from production at the site of hydraulic fracturing (“fracking”) to distribution under city streets. Natural gas fracking has potential to significantly damage watersheds and pollute the air and water in nearby communities, while fugitive emissions from leaking natural gas distribution infrastructure contributes to greenhouse gas emissions and can lead to street tree mortality/morbidity. In order to reach carbon neutrality by 2050, any building with natural gas will need to be transitioned to electric energy therefore encouraging electrification from the onset will expedite the city’s climate agenda. 2. Research Question and Methodology The goal of the following policy memo is to convey scientific evidence in support of building electrification and reducing or eliminating natural gas energy in newly constructed buildings in order to achieve carbon neutrality by 2050. Data to inform this policy brief was compiled from published peer-reviewed literature dating back to the 1970s, through current research. A keyword search was completed using a variety of peer-review journal databases, such as Web of Science and Science Direct, as well as citations collected from the author’s 4 years of research in the field of natural gas energy. Keywords and papers were selected for their focus on the climate change impacts of natural gas energy, both at the site of fracking and at the point of distribution through infrastructure underneath urban streets. Additional data was collected through publicly available databases, including the location of known gas leaks reported by the gas utility company in Cambridge as of the summer of 2020. 3. Key Findings Three specific climate change impacts of natural gas energy stand out considerably in the literature including, 1) air and water pollution at the site of fracking, 2) significant methane emissions from leaking and aging natural gas distribution infrastructure, and 3) damage and death to street trees serving urban populations. Although there are serious climate change and environmental justice issues at the site of fracking for natural gas, no fracking sites are located in Cambridge, MA so while worth noting, this environmental impact will not be reviewed in this memo. 3.1 Methane emissions from natural gas infrastructure Important for Cambridge to consider when planning for their energy future is the age and condition of natural gas distribution pipelines running under the streets across most of the city. Originally brought onto the energy market as a greener alternative to coal, natural gas energy had been associated with climate 15

benefits since its installation decades ago. Recently, research has emerged to show the leakage of 45 methane associated with natural gas sourcing and distribution infrastructure erases any climate benefits of natural gas. Atmospheric methane is a potent greenhouse gas with a ​global warming potential ​86 times 46 more potent than carbon dioxide over a 20-year time period and methane is the primary constituent of uncombusted natural gas traveling through distribution pipelines. , As the distribution pipelines age 47 48 underneath city streets, pipes spring leaks. Some pipes are more leak-prone than others, such as cast iron, wrought iron, and unprotected steel. These leak-prone distribution pipes make up roughly 30% of the 49 distribution infrastructure in the MA contributing to many gas leaks across the state. Figure 1 shows the 50 location of currently unrepaired natural gas leaks in Cambridge, MA as reported by the gas utility to the Massachusetts Department of Public Utilities. Figure 1. 202 unrepaired gas leaks in Cambridge, MA from 2019 Eversource utility report to the MA D.P.U. Google map courtesy of HEET, a Cambridge-based home energy non-profit organization. URL: https://heetma.org/gas-leaks/gas-leak-maps/​ accessed: August 24, 2020. Although pipeline replacement projects have increased in recent years, gas leaks across municipalities still contribute to greenhouse gas emissions. Measuring exact methane concentrations from leaking natural gas infrastructure has proved challenging, in part due to the outdated standards for estimating 45 ​Delborne et al. 2020. 46 ​Howarth, 2014. 47 Brandt et al. 2014. 48 ​Global warming potential - ​“Each gas has a specific global warming potential, which allows comparisons of the amount of energy the emissions of 1 ton of a gas will absorb over a given time period… compared with the emissions of 1 ton of CO2”​ ​- ​Valero, 2019. 49 ​EPA, 1996. 50 ​D.O.E., 2017. 16

methane emissions from gas pipelines that the US Environmental Protection Agency (EPA) is still utilizing. Recent studies have tried to update these methane emission standards to better understand the 51 contribution of leaking gas infrastructure to total greenhouse gas emissions. Hendrick and co-authors focused in the Greater Boston Area and found that not all gas leaks are equal and from their survey of 100 gas leaks, found that the top 7% of leaks contributed to 50% of the total methane emissions measured. 52 Although the science of methane emissions from natural gas distribution infrastructure is still emerging, there is consensus that methane emissions from natural gas leaks cannot be overlooked when making decisions about achieving carbon neutrality and electrifying Cambridge. 3.2 Natural gas leaks and street trees Another area of climate change concerns associated with natural gas infrastructure is the damage to urban vegetation and street trees that results from aging and leaking distribution pipelines. When methane leaks from a pipe buried underneath a city street, a path of least resistance for the gas to reach the atmosphere exists in the soil pits where street trees and other urban vegetation is planted. Studies dating back to the 1970s characterize the interactions between methane and the soil of tree pits. , As methane enters the 53 54 soil, it begins to displace the oxygen in the soil, leaving less oxygen available for the roots of urban vegetation to take up. Additional changes occur in the microbial communities in these tree pits, as the 55 influx of methane causes a growth in ​methanotroph​ populations, which further deplete oxygen available for the tree. , 56 57 More recent research conducted in Chelsea, MA aimed to quantify the effects of natural gas leaks on urban street tree health. This study concluded that dead or dying street trees across Chelsea were 30 58 times more likely to have been exposed to methane, compared to healthy control trees. Damage to urban street trees and vegetation have significant climate change impacts due in large part to the ecosystem services provided to cities by a robust urban canopy. Street trees have demonstrated ability to reduce urban temperatures through shading and ​evaporative cooling ​which can help address issues associated with the ​urban heat island effect​. , , Additionally, street trees provide flood control, consume carbon 59 60 61 51 ​Lamb et al. 2015. 52 ​Hendrick et al. 2016. 53 ​Davis, 1977. 54 ​Hoeks, 1972. 55 Trees and other vegetation require oxygen in the soil to respire. When the sun is not out, or it is night, plants require oxygen from their roots to create energy to grow. - ​Plaxton et al. 2006. 56 ​Adamse et al. 1971. 57 ​Methanotroph​ - a microbial organism that oxidizes methane for energy. ​Bridgham et al. 2013. 58 ​Schollaert et al. 2020. 59 ​Norton et al. 2015. 60 ​Evaporative cooling - ​refers to a phenomenon in trees caused by the evaporation of water on the leaves. Trees release water into the atmosphere through transpiration, and as this water turns from a liquid to gas, the surrounding air is cooled. ​USDA. 2019. 61 ​Urban heat island effect -​ refers to the phenomenon “whereby ambient temperatures are significantly higher in cities than in rural areas due to the absorption and accumulation of heat in pavements and other physical interactions” ​Carpio et al. 2020. 17

dioxide, and provide aesthetic and recreational value. , , According to the Cambridge Urban Canopy 62 63 64 report from 2016, Cambridge does well at caring for their tree canopy, compared to estimates in other cities at 96.7% for young trees and 90.8% for old trees. Maintaining current practices for caring for 65 street trees and removing further threat from natural gas leaks will be crucial moving forward to promote a robust urban canopy in Cambridge. 4. Recommendations / Next Steps Promoting building electrification will help to prepare the City of Cambridge to reach its goals of carbon neutrality by 2050 and reduce the environmental impacts of natural gas energy. Aging natural gas infrastructure will continue to leak and spew uncombusted gas, primarily methane, into the atmosphere contributing to the greenhouse gas emissions of the city and damaging urban vegetation and street trees. In order to maintain and grow the beauty of Cambridge’s urban canopy and promote a sustainable and equitable future for the city, transitioning off of natural gas will be key. Banning natural gas in new construction buildings in favor of electrification is a logical place to start because there will be no additional reliance on the aged natural gas system moving forward. Beginning a climate forward development plan for the city, and creating jobs in the process, will help the city achieve its climate action goals. A failure to do so could delay achievement of the city’s climate change goals, continue to damage the environment, and commit the city to a future reliance on natural gas and fossil fuels that is unnecessary. 62 ​Soares et al. 2010. 63 ​Freedman et al. 1996. 64 ​Bolund & Hunhammar, 1999. 65Boukili et al. 2016. 18

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