Editing IPCC:AR6/WGIII/Chapter-9 (section)

=== 9.8.2 Climate Mitigation Actions in Buildings and Health Impacts ===

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==== 9.8.2.1 Lack of Access to Clean Energy ====

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In 2018, approximately 2.8 billion people worldwide, most of whom live in Asia and Africa, still use polluting fuels, such as fuelwood, charcoal, dried crops, cow dung, and so on, in low-efficiency stoves for cooking and heating, generating household air pollution (HAP), which adversely affects the health of the occupants of the dwellings, especially children and women ( [[#World%20Health%20Organization--2016|World Health Organization 2016]] ; [[#Rahut--2017|Rahut et al. 2017]] ; [[#Mehetre--2017|Mehetre et al. 2017]] ; [[#Das--2018|Das et al. 2018]] ; Liu et al. 2018; [[#Quinn--2018|Quinn et al. 2018]] ; [[#Rosenthal--2018|Rosenthal et al. 2018]] ; [[#Xin--2018|Xin et al. 2018]] ; [[#IEA--2020a|IEA 2020a]] ). Exposure to HAP from burning these fuels is estimated to have caused 3.8 million deaths from heart diseases, strokes, cancers, acute lower respiratory infections in 2016 (World Health Organization 2018). It is acknowledged that integrated policies are needed to address simultaneously universal energy access, limiting climate change and reducing air pollution ( [[#World%20Health%20Organization--2016|World Health Organization 2016]] ). [[#Rafaj--2018|Rafaj et al. (2018)]] showed that a scenario achieving these SDGs in 2030 will imply in 2040 two million fewer premature deaths from HAP compared to current levels, and 1.5 million fewer premature deaths in relation to a reference scenario, which assumes the continuation of existing and planned policies. The level of incremental investment needed in developing countries to achieve universal access to modern energy was estimated at around USD0.8 trillion cumulatively to 2040 in the scenarios examined ( [[#Rafaj--2018|Rafaj et al. 2018]] ).

At the core of these policies is the promotion of improved cook-stoves and other modern energy-efficient appliances to cook (for the health benefits of improved cook-stoves see for example ( [[#García-Frapolli--2010|García-Frapolli et al. 2010]] ; [[#Malla--2011|Malla et al. 2011]] ; [[#Aunan--2013|Aunan et al. 2013]] ; [[#Jeuland--2018|Jeuland et al. 2018]] ), as well as the use of non-solid fuels by poor households in developing countries (Figure 9.19). Most studies agree that the use of non-solid energy options such as LPG, ethanol, biogas, piped natural gas, and electricity is more effective in reducing the health impacts of HAP compared to improved biomass stoves (see for example [[#Larsen--2016|Larsen 2016]] ; [[#Rosenthal--2018|Rosenthal et al. 2018]] ; [[#Steenland--2018|Steenland et al. 2018]] ; [[#Goldemberg--2018|Goldemberg et al. 2018]] ). On the other hand, climate change mitigation policies (e.g., carbon pricing) may increase the costs of some of these clean fuels (e.g., LPG, electricity), slowing down their penetration in the poor segment of the population and restricting the associated health benefits ( [[#Cameron--2016|Cameron et al. 2016]] ). In this case, appropriate access policies should be designed to efficiently shield poor households from the burden of carbon taxation ( [[#Cameron--2016|Cameron et al. 2016]] ). The evaluation of the improved biomass burning cook-stoves under real-world conditions has shown that they have lower than expected, and in many cases limited, long-run health and environmental impacts, as the households use these stoves irregularly and inappropriately, fail to maintain them, and their usage decline over time ( [[#Patange--2015|Patange et al. 2015]] ; [[#Aung--2016|Aung et al. 2016]] ; [[#Hanna--2016|Hanna et al. 2016]] ; [[#Wathore--2017|Wathore et al. 2017]] ). In this context, the various improved cook-stoves programs should consider the mid- and long-term needs of maintenance, repair, or replacement to support their sustained use ( [[#Shankar--2014|Shankar et al. 2014]] ; [[#Schilmann--2019|Schilmann et al. 2019]] ).

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[[File:c44c1109ef2fbb4a3f7327be7d94336b IPCC_AR6_WGIII_Figure_9_19.png]]

'''Figure 9.19 | Trends on energy access: historical based on IEA statistics data and scenarios based on IEA WEO data.'''

Electrification of households in rural or remote areas results also to significant health benefits. For example, in El Salvador, rural electrification of households leads to reduced overnight air pollutants concentration by 63% due to the substitution of kerosene as a lighting source, and 34–44% less acute respiratory infections among children under six ( [[#Torero--2015|Torero 2015]] ). In addition, the connection of the health centres to the grid leads to improvements in the quality of health care provided ( [[#Lenz--2017|Lenz et al. 2017]] ).

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==== 9.8.2.2 Energy/fuel Poverty, Indoor Environmental Quality and Health ====

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Living in fuel poverty, and particularly in cold and damp housing is related to excess winter mortality and increased morbidity rates due to respiratory and cardiovascular diseases, arthritic and rheumatic illnesses, asthma, and so on ( [[#Lacroix--2015|Lacroix and Chaton 2015]] ; [[#Payne--2015|Payne et al. 2015]] ; [[#Camprubí--2016|Camprubí et al. 2016]] ; [[#Wilson--2016|Wilson et al. 2016]] ; [[#Ormandy--2016|Ormandy and Ezratty 2016]] ; [[#Thema--2017|Thema et al. 2017]] ). In addition, lack of affordable warmth can generate stress related to chronic discomfort and high bills, fear of falling into debt, and a sense of lacking control, which are potential drivers of further negative mental health outcomes, such as depression ( [[#Howden-Chapman--2012|Howden-Chapman et al. 2012]] ; [[#Liddell--2015|Liddell and Guiney 2015]] ; [[#Payne--2015|Payne et al. 2015]] ; [[#Wilson--2016|Wilson et al. 2016]] ). Health risks from exposure to cold and inadequate indoor environmental quality may be higher for low-income, energy-poor households, and in particular for those with elderly relatives, young children, and members with existing respiratory illness ( [[#Payne--2015|Payne et al. 2015]] ; [[#Thomson--2017b|Thomson et al. 2017b]] ; Nunes 2019). High temperatures during summer can also be dangerous for people living in buildings with inadequate thermal insulation and inappropriate ventilation ( [[#Ormandy--2016|Ormandy and Ezratty 2016]] ; [[#Sanchez-Guevara--2019|Sanchez-Guevara et al. 2019]] ; [[#Thomson--2019|Thomson et al. 2019]] ). Summer fuel poverty (or summer overheating risk) may increase significantly in the coming decades under a warming climate ( [[#9.7|Section 9.7]] ), with the poorest, who cannot afford to install air conditioning, and the elderly ( [[#Nunes--2020|Nunes 2020]] ) being the most vulnerable.

Improved energy efficiency in buildings contributes in fuel poverty alleviation and brings health gains through improved indoor temperatures and comfort as well as reduced fuel consumption and associated financial stress ( [[#Curl--2015|Curl et al. 2015]] ; [[#Lacroix--2015|Lacroix and Chaton 2015]] ; [[#Liddell--2015|Liddell and Guiney 2015]] ; [[#Thomson--2015|Thomson and Thomas 2015]] ; [[#Willand--2015|Willand et al. 2015]] ; [[#Poortinga--2018|Poortinga et al. 2018]] ). On the other hand, households suffering most from fuel poverty experience more barriers for undertaking building retrofits ( [[#Braubach--2013|Braubach and Ferrand 2013]] ; [[#Camprubí--2016|Camprubí et al. 2016]] ; [[#Charlier--2018|Charlier et al. 2018]] ), moderating the potential health gains associated with implemented energy efficiency programs. This can be avoided if implemented policies to tackle fuel poverty target the most socially vulnerable households ( [[#Lacroix--2015|Lacroix and Chaton 2015]] ; [[#Camprubí--2016|Camprubí et al. 2016]] ). [[#Mzavanadze--2018a|Mzavanadze (2018a)]] estimated that in EU-28 accelerated energy efficiency policies, reducing the energy demand in residential sector by 333 TWh in 2030 compared to a reference scenario, coupled with strong social policies targeting the most vulnerable households, could deliver additional co-benefits in the year of 2030 of around 24,500 avoided premature deaths due to indoor cold and around 22,300 disability adjusted life years (DALYs) of avoided asthma due to indoor dampness. The health benefits of these policies amount to EUR4.8 billion in 2030. The impacts on inhabitants in developing countries would be much greater than those in EU-28 owing to the much higher prevalence of impoverished household.

Apart from thermal comfort, the internal environment of buildings impacts public health through a variety of pathways including inadequate ventilation, poor indoor air quality, chemical contaminants from indoor or outdoor sources, outdoor noise, or poor lighting. The implementation of interventions aiming to improve thermal insulation of buildings combined with inadequate ventilation may increase the risk of mould and moisture problems due to reduced air flow rates, leading to indoor environments that are unhealthy, with the occupants suffering from the sick building syndrome symptoms ( [[#Willand--2015|Willand et al. 2015]] ; [[#Cedeño-Laurent--2018|Cedeño-Laurent et al. 2018]] ; [[#Wierzbicka--2018|Wierzbicka et al. 2018]] ). On the other hand, if the implementation of energy efficiency interventions or the construction of green buildings is accompanied by adequate ventilation, the indoor environmental conditions are improved through less moisture, mould, pollutant concentrations, and allergens, which result in fewer asthma symptoms, respiratory risks, chronic obstructive pulmonary diseases, heart disease risks, headaches, cancer risks, and so on ( [[#Allen--2015|Allen et al. 2015]] ; [[#Hamilton--2015|Hamilton et al. 2015]] ; [[#Thomson--2015|Thomson and Thomas 2015]] ; [[#Cowell--2016|Cowell 2016]] ; [[#Doll--2016|Doll et al. 2016]] ; [[#Wilson--2016|Wilson et al. 2016]] ; [[#Militello-Hourigan--2018|Militello-Hourigan and Miller 2018]] ; [[#Underhill--2018|Underhill et al. 2018]] ; [[#Cedeño-Laurent--2018|Cedeño-Laurent et al. 2018]] ). [[#Fisk--2018|Fisk (2018)]] showed that increased ventilation rates in residential buildings results in health benefits ranging from 20% to several-fold improvements; however, these benefits do not occur consistently, and ventilation should be combined with other exposure control measures. As adequate ventilation imposes additional costs, the sick building syndrome symptoms are more likely to be seen in low income households ( [[#Shrubsole--2016|Shrubsole et al. 2016]] ).

The health benefits of residents due to mitigation actions in buildings are significant (for a review see [[#Maidment--2014|Maidment et al. 2014]] ; [[#Thomson--2015|Thomson and Thomas 2015]] ; [[#Fisk--2020|Fisk et al. 2020]] ), and are higher among low income households and/or vulnerable groups, including children, the elderly and those with pre-existing illnesses ( [[#Maidment--2014|Maidment et al. 2014]] ; [[#IEA--2014|IEA 2014]] ; [[#Ortiz--2019|Ortiz et al. 2019]] ). [[#Tonn--2018|Tonn et al. (2018)]] estimated that the health-related benefits attributed to the two weatherisation programs implemented in the US in 2008 and 2010 exceeds by a factor of 3 the corresponding energy cost savings yield. [[#IEA--2014|IEA (2014)]] also found that the health benefits attributed to energy efficiency retrofit programs may outweigh their costs by up to a factor of 3. [[#Ortiz--2019|Ortiz et al. (2019)]] estimated that the energy retrofit of vulnerable households in Spain requires an investment of around EUR10.9–12.3 thousands per dwelling and would generate an average saving to the healthcare system of EUR372 per year and dwelling (due to better thermal comfort conditions in winter).

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==== 9.8.2.3 Outdoor Air Pollution ====

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According to World Health Organization (2018) around 4.2 million premature deaths worldwide (in both cities and rural areas) are attributed to outdoor air pollution. According to the results of the quantitative model ( [[#Gu--2018|Gu et al. 2018]] ), the premature mortalities attributed to PM 2.5 and O 3 emissions may reach 168000–1796000 (95% Cl) in 2010. Mitigation actions in residential and non-residential sectors decrease the amount of fossil fuels burnt either directly in buildings (for heating, cooking, etc.) or indirectly for electricity generation and thereby reduce air pollution (e.g., PM, O 3 , SO 2 , NO x ), improve ambient air quality and generate significant health benefits through avoiding premature deaths, lung cancers, ischemic heart diseases, hospital admissions, asthma exacerbations, respiratory symptoms, and so on ( [[#Levy--2016|Levy et al. 2016]] ; [[#Balaban--2017|Balaban and Puppim de Oliveira 2017]] ; [[#MacNaughton--2018|MacNaughton et al. 2018]] ; [[#Karlsson--2020|Karlsson et al. 2020]] ). Several studies have monetised the health benefits attributed to reduced outdoor air pollution due to the implementation of mitigation actions in buildings, and their magnitude expressed as a ratio to the value of energy savings resulting from the implemented interventions in each case, are in the range of 0.08 in EU, 0.18 in Germany, 0.26–0.40 in US, 0.34 in Brazil, 0.47 in Mexico, 0.74 in Turkey, 8.28 in China and 11.67 in India ( [[#Joyce--2013|Joyce et al. 2013]] ; [[#Levy--2016|Levy et al. 2016]] ; [[#Diaz-Mendez--2018|Diaz-Mendez et al. 2018]] ; [[#MacNaughton--2018|MacNaughton et al. 2018]] ). In developed economies, the estimated co-benefits are relatively low due to the fact that the planned interventions influence a quite clean energy source mix ( [[#Tuomisto--2015|Tuomisto et al. 2015]] ; [[#MacNaughton--2018|MacNaughton et al. 2018]] ). On the other hand, the health co-benefits in question are substantially higher in countries and regions with greater dependency on coal for electricity generation and higher baseline morbidity and mortality rates ( [[#Kheirbek--2014|Kheirbek et al. 2014]] ; [[#MacNaughton--2018|MacNaughton et al. 2018]] ).

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