Strategies and tactics to reduce the impact of healthcare on climate change: systematic review
BMJ 2024; 387 doi: https://doi.org/10.1136/bmj-2024-081284 (Published 08 October 2024) Cite this as: BMJ 2024;387:e081284
- Jeffrey Braithwaite
, professor1 2 3, - Carolynn L Smith, research fellow1 2,
- Elle Leask, research assistant1,
- Shalini Wijekulasuriya, research assistant1 2,
- Kalissa Brooke-Cowden, research assistant4,
- Georgia Fisher, post-doctoral fellow1,
- Romika Patel, research assistant1,
- Lisa Pagano, post-doctoral fellow1,
- Hania Rahimi-Ardabili, research fellow4,
- Samantha Spanos, post-doctoral fellow1,
- Christina Rojas, project officer1,
- Andrew Partington, research fellow1 5,
- Ella McQuillan, research assistant1,
- Genevieve Dammery, research assistant1 2,
- Ann Carrigan, research fellow1 2,
- Lauren Ehrenfeld, research assistant1,
- Enrico Coiera, professor2 4,
- Johanna Westbrook, professor2 6,
- Yvonne Zurynski, professor1 2
- 1Centre for Healthcare Resilience and Implementation Science, Australian Institute of Health Innovation, Macquarie University, Sydney, 2109, Australia
- 2NHMRC Partnership Centre for Health System Sustainability, Australian Institute of Health Innovation, Macquarie University, Sydney, 2109, Australia
- 3International Society for Quality in Health Care, Dublin, Ireland
- 4Centre for Health Informatics, Australian Institute of Health Innovation, Macquarie University, Sydney, 2109, Australia
- 5Flinders Health and Medical Research Institute, Flinders University, Adelaide, 5042, Australia
- 6Centre for Health Systems and Safety Research, Australian Institute of Health Innovation, Macquarie University, Sydney, 2109, Australia
- Correspondence to: J Braithwaite, jeffrey.braithwaite{at}mq.edu.au (or @JBraithwaite1 on X)
- Accepted 18 September 2024
Abstract
Objective To review the international literature and assess the ways healthcare systems are mitigating and can mitigate their carbon footprint, which is currently estimated to be more than 4.4% of global emissions.
Design Systematic review of empirical studies and grey literature to examine how healthcare services and institutions are limiting their greenhouse gas (GHG) emissions.
Data sources Eight databases and authoritative reports were searched from inception dates to November 2023.
Eligibility criteria for selecting studies Teams of investigators screened relevant publications against the inclusion criteria (eg, in English; discussed impact of healthcare systems on climate change), applying four quality appraisal tools, and results are reported in accordance with PRISMA (preferred reporting items for systematic reviews and meta-analyses).
Results Of 33 737 publications identified, 32 998 (97.8%) were excluded after title and abstract screening; 536 (72.5%) of the remaining publications were excluded after full text review. Two additional papers were identified, screened, and included through backward citation tracking. The 205 included studies applied empirical (n=88, 42.9%), review (n=60, 29.3%), narrative descriptive (n=53, 25.9%), and multiple (n=4, 2.0%) methods. More than half of the publications (51.5%) addressed the macro level of the healthcare system. Nine themes were identified using inductive analysis: changing clinical and surgical practices (n=107); enacting policies and governance (n=97); managing physical waste (n=83); changing organisational behaviour (n=76); actions of individuals and groups (eg, advocacy, community involvement; n=74); minimising travel and transportation (n=70); using tools for measuring GHG emissions (n=70); reducing emissions related to infrastructure (n=63); and decarbonising the supply chain (n=48).
Conclusions Publications presented various strategies and tactics to reduce GHG emissions. These included changing clinical and surgical practices; using policies such as benchmarking and reporting at a facility level, and financial levers to reduce emissions from procurement; reducing physical waste; changing organisational culture through workforce training; supporting education on the benefits of decarbonisation; and involving patients in care planning. Numerous tools and frameworks were presented for measuring GHG emissions, but implementation and evaluation of the sustainability of initiatives were largely missing. At the macro level, decarbonisation approaches focused on energy grid emissions, infrastructure efficiency, and reducing supply chain emissions, including those from agriculture and supply of food products. Decarbonisation mechanisms at the micro and meso system levels ranged from reducing low value care, to choosing lower GHG options (eg, anaesthetic gases, rescue inhalers), to reducing travel. Based on these strategies and tactics, this study provides a framework to support the decarbonisation of healthcare systems.
Systematic review registration PROSPERO: CRD42022383719.
Introduction
The direct and indirect human health impacts of climate change have been well documented over the past two decades. The 2015 Paris Agreement and subsequent research have painstakingly established the association between planetary and human health.1234 However, until recently, less attention has been directed towards the impact healthcare systems have on climate change. This issue is gaining momentum, spurred on by the implementation of the Paris Agreement and the introduction of the UK National Health Service (NHS) net zero carbon strategy.56
In essence, healthcare systems occupy a special place; although they are on the frontlines in dealing with climate induced demand for healthcare, they are also major emitters.78 Healthcare systems must therefore address a predicament: maintenance of high quality care with the resilience and capacity to respond to escalating climate induced demands; and mitigation of their own, substantial contributions to the climate crisis. The action required to manage the complexities of the environmental and societal costs of delivering health services is not trivial. Healthcare systems, notably hospital facilities, are energy intensive, high consumption organisations that produce considerable quantities of waste.891011 Although there is an irrefutable duty of care to patients and a fundamental commitment to do no harm at the point of delivery, healthcare systems have until recently remained largely unrecognised contributors to the climate crisis.12 However, healthcare systems are well positioned as environmental stewards to get their own house in order and promote benefits—lowering the collective carbon footprint while simultaneously improving long term health by reducing low value care.
That said, healthcare systems currently lag behind other service sectors in reducing carbon emissions.613 To be compliant with the Paris Agreement and contribute to the Intergovernmental Panel on Climate Change’s target of limiting global warming to 1.5°C above preindustrial levels, healthcare must play its part, aiming for net zero carbon emissions by 2050.131415 There is a need to act in a swift and decisive manner because humanity has a limited window to achieve significant progress in reducing carbon emissions or irreversible changes will exceed the boundaries of the planet.16
Most estimates place average global emissions from healthcare at about 4.4%, with a country range of 4-8.5%.15 As confronting as these numbers are, it is possible they will get worse before they get better.17 More frequent large scale events stimulated by climate change (eg, bushfires, floods, cyclones, heatwaves, and other weather sequelae) will require more carbon inducing care, placing additional, often overwhelming loads on overstretched healthcare systems grappling to contend with the current high burden of chronic diseases, non-communicable diseases (such as cardiovascular diseases), communicable diseases, constant introduction of new interventions and technologies as we discover new ways to manage disease, and ageing populations.10111819 With slow progress on reduction strategies, increased demand on healthcare systems in turn generates further environmental impacts in a vicious cycle (fig 1).
Positive feedback loop reflecting current association between the healthcare system and climate change. GHG=greenhouse gas
Against that backdrop, we sought to examine the quality and quantity of global evidence on ways in which healthcare systems contribute to climate change and the proposed and implemented ways of reducing the effects of healthcare systems on the climate. Table 1 presents our key terms.
Glossary of terms
Methods
Search strategy and selection criteria
In this review, we assessed the quality and quantity of evidence on ways in which healthcare systems contribute to climate change and the approaches, models, and tools available to decarbonise healthcare systems. The review was prospectively registered on PROSPERO (CRD42022383719) and reported in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines (supplementary materials 1 and 2).35
The search strategy was designed by the review team in conjunction with a research librarian, and run across eight electronic databases. Seven of these databases were searched from their respective inception dates to November 2023: Business Source Premier, CINAHL, Cochrane Reviews, Embase, Health Business (EBSCO), Medline, and Web of Science. Scopus was searched from 1990 to November 2023. Supplementary material 3 gives more details on the search terms.
Publications were eligible if they were full text articles in peer reviewed journals. All study designs (eg, case studies, reviews) were included. Reports from authoritative international agencies (eg, World Health Organization, World Bank, United Nations, and Organisation for Economic Co-operation and Development) or government reports at a federal or national level were also eligible if assessed to be of suitable quality. A primary focus on the effects of human healthcare systems on climate change was required. Articles were excluded if they were not available in English, were not published as full papers, or did not have a primary focus on healthcare systems’ effects on or contribution to climate change. Supplementary material 4 presents full inclusion and exclusion criteria.
Records identified in the database search were imported into Rayyan, a screening software tool,36 and duplicates removed. For inter-rater reliability, pilot screening of titles and abstracts was conducted on a set of 200 randomly selected publications and any resulting discrepancies were resolved by the group. In our original review protocol, it was planned that six investigators would screen records in pairs. However, given the large volume of literature identified in the search, 15 investigators screened records in pairs. The full set of titles and abstracts retrieved from searches were then independently double screened for inclusion by investigators working in teams of two or three (EL, LE, EM, GD, CLS, AC, KB-C, SW, GF, RP, LP, HRA, SS, CR, AP). The full texts of the remaining publications were then duplicate screened against the inclusion criteria to ensure consistency in the final set of included texts. Supplementary material 5 presents reasons for exclusion during the full text review. Regular meetings took place to resolve any disagreements by consensus at each step of the process, with JB available as arbiter.
Data analysis
Data extraction and quality appraisal were conducted independently by investigators, and verified during synthesis processes. Four quality appraisal tools were applied to assess the quality of included publications: Joanna Briggs Institute critical appraisal checklist for systematic reviews and research synthesis37; Mixed-Methods Appraisal Tool (MMAT)38; Scale for the quality Assessment of Narrative Reviews (SANRA)39; and Authority, Accuracy, Coverage, Objectivity, Date, Significance (AACODS) tool for evaluation and critical appraisal of grey literature.40 After initial appraisal, the quality of each article was assigned to one of four categories: critically low, low, moderate, high. Articles determined to be of critically low quality were excluded from analysis; supplementary materials 6-10 provide further details.
A purpose built data extraction workbook was developed in Microsoft Excel. Data extraction variables included publication details (author, title, year, country of publication), healthcare system level (micro, meso, macro), healthcare system sector (eg, primary care, surgery, mental health), and measurement of climate impact (eg, carbon footprint). A thematic analysis of the extracted data was performed using an inductive approach to identify themes emerging from the literature.41 One reviewer (SW) first familiarised themselves with all extracted data, and then created a set of six initial broad themes and 24 subthemes using inductive thematic analysis.41 A subgroup of five reviewers (CLS, KBC, GD, SW, EL) discussed and revised the initial coding of themes to 12 themes. The whole authorship team conducted a review of these broad themes for content and accuracy, and the final nine themes were then reviewed by the senior author (JB). Once the nine broad themes had been developed, a subgroup of reviewers (CLS, KBC, GD, SW, EL, EM) met to code the data within each broad theme into appropriate subthemes, again using an inductive thematic analysis. Two broad categories were also developed to frame the themes as avenues of enacting change (overarching strategies), or specific approaches for reducing GHG emissions in healthcare systems (decarbonisation tactics). The whole authorship team reviewed and approved all categories and subthemes, which were finalised by the senior author (JB). Supplementary materials 11-13 provide details.
Patient and public involvement
This research did not focus on any specific patient population. Although no patients were directly involved in setting the research question or conducting the review, we ensure we have healthcare consumers’ input, expertise and advice on the progress of our research at the intersection of climate change, health, and healthcare, which feeds into and shapes all our work in this area. Healthcare consumers are an integral part of our results dissemination strategy.
Results
Study selection and quality assessment
Electronic database searches identified 33 737 publications, 15 793 of which were duplicates, leaving 17 944 publications for title and abstract screening; 739 studies met the inclusion criteria for full text screening. Of these, 28 were excluded because they could not be retrieved, leaving 711 texts to be screened (fig 2). Two additional papers were identified, screened, and included through backward citation tracking.
Preferred reporting items for systematic reviews and meta-analyses (PRISMA) diagram
Most of the articles in this review were appraised as high (n=112, 54.6%) or moderate (n=80, 39.0%) quality. Only 13 articles (6.3%) were identified as lower quality but were included because they provided valuable information for the review. Seven studies were considered ineligible based on critically low quality appraisal ratings (supplementary materials 6-10). After full text screening and quality appraisal, 205 publications were included (fig 2).
Study characteristics
Types of studies
Included publications were categorised by study design (table 2): empirical studies; reviews including narrative, scoping, and systematic; non-empirical “narrative descriptive” publications (eg, case studies, reports); and those applying multiple methods. Studies were also categorised based on the level of the healthcare system to which they pertained: micro, meso, or macro (table 2; see table 1 for full definitions).
Overview of key characteristics of included publications (n=205)
Geographical focus
High income countries were over-represented in the included publications (n=101, 69.2%, excluding reviews). The most commonly discussed country was the United States (n=27, 13.2%), followed by the UK (n=21, 10.2%), Australia (n=17, 8.3%), and Canada (n=14, 6.8%). Figure 3 depicts the study setting by country. Many publications (n=30, 14.6%) focused on the macro level without discussing a specific country or region.64243444546474849505152535455565758596061626364656667686970
Setting of included empirical publications by country. Some publications refer to more than one country. Countries were counted for all empirical publications
Publication dates
Most included records were published in recent years (fig 4), with 85.4% (n=175) from 2019 onwards, indicating the growing interest in this topic.
Topics covered
A wide range of healthcare related topics were discussed, including surgery (n=36)242751547172737475767778798081828384858687888990919293949596979899100101102; internal medicine specialties (ie, renal services, gynaecological services; n=18)235775103104105106107108109110111112113114115116117; digital health (n=15)596671118119120121122123124125126127128129; primary care (n=15)53566375130131132133134135136137138139140; hospitals (n=14)8292141142143144145146147148149150151152; supply chains (eg, procurement; n=10)4244153154155156157158159160; oncology (n=8)4858161162163164165166; pharmaceuticals (n=7)4547167168169170171; diagnostics (n=6)52172173174175176; chronic condition treatment (n=5)2861177178179; workforce (n=5)180181182183184; pathology services (n=5)75174185186187; dentistry (n=4)60188189190; critical care (n=3)90191192; clinical trials (n=2)67193; emergency medical services (n=2)26194; mental health services (n=2)195196; outpatient care (n=2)197198; screening (n=2)199200; travel related to doctors’ medical education (n=1)201; and palliative care (n=1).202 Fifty papers examined the system as a whole, taking a macro perspective.671119254346495055626465686970203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236
Scope
Twenty nine (14.1%) publications specifically used terminology that refers to GHG emissions according to three emission scopes defined by the Greenhouse Gas Protocol237 (direct emissions, indirect emissions from energy use, indirect supply chain emissions).7274445474850556568698185125142152166172184193197200202207209219224229232Table 3 presents definitions of the three scopes.
Three scopes of carbon footprint
Measurement of healthcare emissions
Forty eight publications developed or applied specific models or tools to measure healthcare emissions; some publications used several models or tools (table 4). Models included life cycle assessment (LCA; n=27),607684104107111119122128130141142155162173174175179186190193200209212213223231 economic input-output LCA (n=2),197212 LCA multiregion input-output models (n=1),25 environmentally extended input-output models (n=6),7112477213232 environmentally extended multiregional input-output model (n=4),4344231232 and the Bilan Carbone model (n=1).166 Tools used in the literature included carbon calculators (n=6),52101115121165176 Carbon Trust recommendations (n=1),26 the Eyefficiency tool (n=1),89 the Pollard model (n=1),188 the Ringelmann smoke chart (n=1),157 and the US Environmental Protection Agency’s waste reduction model (n=1).144 Other studies (n=16) used publicly available datasets (eg, UK Department of Business, Energy, and Industrial Strategy conversion factor data; environmental impact data provided by the German Federal Environment Agency), or previously published literature to quantify GHG emissions in their facilities.74839499110113123126129148161162163168178202
Tools for measuring healthcare emissions from empirical studies
Key themes emerging from the literature
From the thematic analysis, nine themes emerged across the included publications, which were then grouped into one of two categories: overarching strategies (table 5) or decarbonisation tactics (table 6). The most frequently discussed overarching strategy was the need for effective policies and governance surrounding healthcare sustainability (n=97) and the most common decarbonisation tactic was changing clinical and surgical practices (n=107). Papers discussing numerous themes or subthemes were included in several categories.
Publications in the overarching strategies category, grouped into themes
Publications in the decarbonisation tactics category, grouped into themes
Overarching strategies
Policy and governance level initiatives
The need for policies and incentives to promote, guide, monitor, or evaluate changes at the country, state, and facility level was discussed in 97 publications671119232542434445464748495051555657585961636465676869707173767988899596103104105109111112114115117120123124125127128130133136138142143151152154159162166168170171173179180184188191192193200201203205206207208209210212213216217218219220221224231232233234; 39.2% of the publications discussing this theme were empirical studies. The most common strategy focused on priority setting and leadership from national and international bodies (n=51), such as integrating sustainability into policy or setting long term sustainability goals across organisations.67111943465051565759636465677076799596104105109111114115120125127128130133138143152154166170184188206209210216217218220221231232234 This was followed by publications (n=27) that suggested mandating evaluations, benchmarking, and reporting of the carbon footprint for healthcare organisations to strengthen the evidence base for future decision making.67234555586168707388124136142151159168173179205207208212213216219221 An equal number of publications (n=21 each) highlighted using financial policy and incentives for sustainable healthcare processes6424344484970738996123133138143162171180200221224233 and the need for a multisectoral approach to mitigate the carbon footprint of healthcare,7235669738996103112117162191192201203205210217220221233 such as collaborations between large healthcare organisations. Fifteen publications recommended setting targeted emissions reductions.711192545464758707189136193218219
Organisational behaviour change
Organisational change to develop a future ready workforce was dealt with in 76 publications.2425274648495057586365686970717375777980818386919399102103105110112114116127130133135136137138142143150151152154165166171172174178179180181182185187191192195196199202205206207210212216220221228233234235 Roughly 30.3% of the publications discussing this theme were empirical studies. Ongoing education and training within healthcare organisations and tertiary institutions was identified in 59 publications as a way of ensuring the workforce is aware of and equipped for sustainability challenges.24254849505763656869737577798183869199102103110112114116127130133135137138142143150151152165166171172174178179180185187192195196202205206207210212220228233235 Publications discussing organisational leadership focused on implementing multidisciplinary teams, “green champions,” and other organisational role models to manage sustainability at different levels of the healthcare system and empower employee decision making (n=26).274658637071778093105127133135136152154165181182185191196199216221234
Individual and group action
The literature outlined several important roles for individuals and groups in reducing healthcare’s carbon footprint (n=74)7192843484950515356575859616364656667697173818586888990919698102103107108112114116117127130133134135137139142143151160162168171177180181183184192195196210212215216218219220221226229232233236; 20.3% of the publications discussing this theme were empirical studies. Promoting change through advocacy, lobbying, and open support of sustainability initiatives was the focus of 45 publications,74849505153586164656667718185868889909698103107114116117127133134135139142151171180181183184192195196216218232233 including the need for community involvement and education when enhancing the sustainability of healthcare practices (n=21).4353568190103112130133151160168192210212218221229232233236 Several publications emphasised individual responsibility as a key factor in making change (n=15), particularly through engaging with low carbon healthcare and living an active lifestyle.5759637381899196103143160162192220233 Additionally, 15 articles identified benefits of reducing GHGs in the health system, which included financial savings and reducing disease burden.1928506996102107108112137177212215219226
Using tools for measuring and monitoring GHG emissions
The impetus to develop, use, and standardise tools for measuring and monitoring GHG emissions was a prominent theme (n=70 publications).67111926434445474851585961626668697173757779848896103104105107109112114124125137139142146148149154163164171177188192193194200205207208209211212216217218219221222224225227228230231234 Nearly 37.1% of the publications discussing this theme were empirical studies. Evaluative tools, along with existing models such as LCA, can be used to improve decision making on procurement and services, and was a feature of 43 publications.64347585962666873757779848896104105107109112124137139142146149154164192200205208211212216217218224225227230231234 Developing tools to measure GHG emissions and monitor the movement of materials was discussed in 25 publications.7111926434469103124125146171177188193194207209211219221222225227228 Several publications (n=17) emphasised the need for standardised platforms for reporting and comparing the sustainability of products or processes to enable healthcare organisations to make informed decisions about their current practices.726454748516171107114148154163177207211219
Decarbonisation tactics
Changing clinical and surgical practices
Changing clinical and surgical practices as a solution for reducing healthcare’s carbon footprint was advocated in 107 publications67112324252728424348505152545557616366686971737475777879818283848586879091939496979899100101102103106107108109112113114116120126128129130133135138139142143148149151152159161163165166167168169170171173174175177178179183185186189190191192196205212214217224227229230232233234236; 37.4% of the publications discussing this theme were empirical studies. This solution included replacing high GHG practices with lower GHG options (n=80),1123272843485457616368717374757778798182838485868790919394969798100102103106107112113114120126128129133135138139148149152159161163165166167168170171173174177178179183189190192196214217224227229230232233234236 such as choosing anaesthetic gas types and systems with lower carbon footprints.5471738183858696100229 This advocation was also seen in primary care settings (n=6).63130133135138139 As a way of minimising healthcare usage, and thus reducing healthcare’s carbon footprint, 41 publications reinforced the need to assess clinical practices for low value care.67242842515255666869757779939799101109116130142149151152169174175177179185186190191192205212214224229233 This included identifying and reducing unnecessary processes or procedures, minimising drug overprescription, or encouraging a preventative care approach to reduce the need for health services. Reducing water usage during procedures, disinfection and sterilisations, laundry, recycling water, and practising water efficiency were also suggested in six publications.232550108143189
Managing physical waste
Dealing with waste was a focus of 83 publications112543474849505154555760616367727377788081828485868889919395969798100101102104105107110112114116135138142143144149150151152153154155157159160169171177183189190191192198199206210211217218219222223224228229232233234236; 32.5% of the publications discussing this theme were empirical studies. This theme included waste minimisation methods (n=71),1125434748495051545557606163677273777880828485889195969798100101102104105107110112116135138142143144149151152154155159160169171177183189190191192198206211217218219222224228229232233234 such as reducing, reusing, and recycling medical equipment, and using reusable alternatives over disposable items. Several publications highlighted the need for effective segregation and disposal of waste (n=29),505773778081828688899395107114143144150151153157160177183199206210223232236 including choosing disposal methods such as incineration that help minimise carbon emissions.
Minimising travel and transportation
Patient or clinical travel and transportation was emphasised as an important and addressable source of carbon emissions in 70 publications.67244347485155596163697173747984858693949596105109114117119120121122124125126127128131132135137140142148152156161163165166171172174176188190191192193195196197201202217224226228229232233 Some 42.9% of the publications discussing this theme were empirical studies. Using carbon efficient models of care was seen as a method to reduce emissions (n=41), for example, telemedicine or home based treatment options.6244347485159637173747984949596105109119121122124125126128132135148161163165171172176188191195196217228229 A further 25 publications discussed alternative forms of transportation (eg, car sharing, buses, trains, and active travel such as cycling) for patients and clinicians.747556979105114121131137140142152161166174176190192197202224226232233 Streamlining medical services, such as emergency service coordination, redesigning schedules for clinicians to enhance ride share and closing sites with lower use, was discussed in 14 publications.61798693127131132148156161166176188193 Several papers (n=13) also highlighted reducing professionals’ travel (eg, clinicians, researchers, industry partners) for conferences and education as a decarbonisation method.4347516385117120171191195201224228
This theme had the most implementation evaluations. These studies often highlighted reductions in carbon emissions resulting from teleconferencing or telemedicine,122163176 and they also tended to be of high quality.
Strengthening infrastructure
Sixty three papers recommended improvements to healthcare infrastructure2627434750555758596163697273808184889293969798108109112114117118135141142143145146147151152160161171174175184192193194195202206207210211212218221224226228229232234235; 33.3% of the publications discussing this theme were empirical studies. Improving the energy efficiency of healthcare facilities such as hospitals was a feature of 40 publications.475055576163697273808192939798109112135141142143146147152160171192193194207210211212218221224229232234235 For example, consideration of design features such as insulation and passive shading options can help reduce reliance on electrical heating and cooling, and therefore reduce GHG emissions. Thirty four publications advocated for using energy conservation measures—such as turning off appliances when not in use—to help minimise carbon emissions at a facility level.26274357585961637384889697108114117118135143145151152161174175184194195202206221226228229
Decarbonising healthcare supply chains
Forty eight papers proposed decarbonising the supply chains as a way of reducing GHG emissions.7252642434447505455565965738485878998104105110112114127136139142143151152158171175183193194197204210212215218224229232234235 Roughly 39.6% of the publications discussing this theme were empirical studies. Numerous publications (n=43) focused on ways to reduce the carbon footprint by deploying sustainable production and procurement mechanisms within supply chains, such as using sustainable or local sources of food supply, or using supply chains with low emissions.7254243444750545556596573848598104105110112114127136139142143151152158171175183193197210212215218224229232234235 Decarbonising the sources of energy for healthcare by using renewable sources rather than fossil fuel sources and monitoring energy grid consumption was noted in 10 publications.726508789158194204212232
Discussion
Key areas for policy and practice
From our findings we developed a rich picture of the strategies and tactics for reducing the emissions produced by healthcare systems (fig 5). This schematic figure is not an exhaustive example, but rather illustrates how these strategies and tactics to reduce emissions produced by healthcare systems are interconnected and affect flow within and outside of the healthcare system. Authorisation to proceed starts at the top, with effective policies, governance, and high level leadership. Measurement of GHGs through recognised and increasingly sophisticated tools is necessary, and now more pronounced, as is the use of tools and frameworks to report on progress, and make decisions about alternative, greener options. Tools and frameworks for use at micro, meso, and macro levels are now more widely available. Several options for individuals and groups to orchestrate change and improvement, typically targeted at organisations such as hospitals, care facilities for older people, and general practices, have been generated.
Strategies and tactics for reducing healthcare system greenhouse gas (GHG) emissions according to healthcare system level: micro (eg, frontline clinician, including healthcare delivery at a clinic, department, whole hospital, or facility), meso (regional or network level, eg, health district, hospital network), macro (whole healthcare system, including national or global systems)
On decarbonisation specifically, attention was focused on modifying medical, surgical, and other clinical practices, reducing physical waste, and minimising transportation costs or eliminating travel altogether through new clinical models such as virtual care, telehealth, or telemedicine.245963819497120121126165172196 When enacting decarbonisation tactics that affect patient care, it is vital that lower carbon alternatives provide equal or improved patient outcomes compared with current practices and be acceptable to and supported by patients.105 Other specific activities for reducing carbon emissions and greening healthcare, directly or in those services indirectly controlled by healthcare systems, include building new or remediating existing healthcare infrastructure and reducing the carbon footprint along healthcare supply chains. Given the large contribution of supply chain emissions and the high potential for reducing emissions,238 it is surprising that supply chain decarbonisation approaches, including those related to food supply, were less frequently discussed than others. Another surprising lack of attention was discussion at the intersection of universal health coverage and healthcare system decarbonisation because reducing the need for care through primary prevention would have a direct impact on carbon emissions by lowering demand.49140
A way forward
Overall, a framework of useful activities to substantially reduce the carbon budget of healthcare is now available, and represented in figure 5. Although this framework provides a platform to assess these activities, determining which elements would be most effective, and under what conditions, will partly depend on the characteristics of the individual healthcare system.96 Barriers to implementing sustainable practice into healthcare systems might also exist, including patients accepting changes, cost and funding mechanisms, attitudes towards change, and workforce capacity in an already overburdened system. As these decarbonisation approaches are put into practice, any barriers and potential enablers should be explored further.
The included literature was mainly from high income countries. However, we found some examples of lower-middle income country healthcare systems and organisations taking the lead in advancing the overarching strategies identified, such as developing tools to measure emissions (eg, the Aga Khan Health Services (AKHS) freely available tool),44 and the decarbonisation tactics, such as reducing physical waste and emissions from waste disposal (eg, Snigdha and colleagues)158 and improving the environmental sustainability of clinical practices.111156199 Some of the decarbonisation tactics might be more challenging to implement in lower-middle income country healthcare systems, such as strengthening infrastructure.96
Regardless of the setting, having an overarching set of mechanisms and approaches might be useful and highlights the need for a multipronged approach, including how we measure emissions and progress, especially given the range of measuring tools that have emerged. The actions include effective governance and supportive policies, appropriate financing, and strengthening infrastructure and service delivery.20 Collaborative, international, multisectoral leadership is needed to learn from progress elsewhere and to localise and prioritise strategies and support direct actions.
Achieving a step change reduction in emissions is a socially and ethically responsible imperative. In principle, it is feasible and beneficial to roll out these strategies and tactics at scale to achieve systemic change—this is central to the mission of healthcare providers: to do no or less harm, to alleviate suffering, and to improve the health status of the population. Healthcare can set an example for other industries and sectors as responsible environmental stewards. This review suggests that healthcare systems and professionals have recognised their duty and are embracing the necessary changes, but there is a long way to go.
Strengths and limitations
The comprehensive analysis of 18 years of studies, frameworks, and tools that assess and quantify the carbon footprint of healthcare is a key strength of the paper, as is the development of a new framework. Previous reviews did not appear to focus sufficiently on mitigation strategies or use the systematic review methodology.
Our review was limited to papers and authoritative reports written in English, and so some papers might have been missed. However, eight databases were searched, therefore the likelihood of new themes being identified is low. Most of the included literature discussed healthcare systems in high income countries, which is a well known bias. This bias can create challenges when extrapolating identified strategies to low-middle income countries. However, the included papers revealed that healthcare systems in low-middle income countries are undertaking similar strategies to high income countries. A review specifically focused on healthcare systems in low-middle income countries, and the ethical implications of climate change and decarbonisation tactics, is warranted. Inductive approaches, as in this study, allow flexibility and deeper understanding of the data, but introduce issues of inter-rater reliability and bias. Our review used 19 investigators for screening, extraction, synthesis, and interpretation to minimise bias.
Conclusions
We reviewed the literature to generate strategies and tactics for reducing the impact of healthcare systems on climate change. Implementing these strategies should enable substantial progress towards reducing healthcare’s carbon footprint and support a greener health sector powered by renewable sources. However, healthcare systems would need to adapt these approaches to their context and needs to maximise their effects. Healthcare can lead the way in shifting to net zero by 2050, and by doing so we can reduce the burden of patients who would otherwise need more care as a consequence of a warming world.
What is already known on the topic
The carbon footprint of healthcare systems has been estimated at about 4.4% of global emissions, but comprehensive reviews investigating mitigation are lacking
One review took a global approach when examining the environmental impact of healthcare systems; however, this study was not peer reviewed and data were limited to one year
Another study discussed the sustainability of healthcare at a global level, however it was not conducted as a systematic review, and the methods used to evaluate and collate data were unclear
What this study adds
This review includes 18 years of studies, frameworks, and tools assessing the carbon footprint of healthcare systems, and the steps taken to measure and reduce these impacts
Overarching strategies and specific tactics, models, and tools were identified that could be used to decarbonise healthcare systems, aiming to reach net zero emissions by 2050
Ethics statements
Ethical approval
No individual participant data are included in this manuscript. All data are aggregated from existing publications. Ethics approval was therefore not required. We attest that we have obtained appropriate permissions and paid any required fees for use of copyright protected materials.
Data availability statement
All datasets generated and analysed for this study, including the search strategy, list of the included and excluded studies, data extracted, analysis plans, and quality assessment are available in the article or supplementary material and upon request from the corresponding author. No individual participant data were used for this study.
Acknowledgments
The authors thank Imogen Benson for providing desktop support; Mary Simons, a clinical librarian at Macquarie University who we consulted to devise the original search strategy; and Jeremy Cullis, a clinical librarian at Macquarie University, who assisted with the database search.
Footnotes
Contributors: JB conceived the project and led the work. CLS and YZ co-conceived the project. LE, EL, GD, CLS, AC, KB-C, EM, SW, GF, RP, LP, HRA, SS, CR, and AP screened the publications. CLS, SW, KB-C, EM, GD, EL, RP, GF, LP, HRA, SS, CR, and AP extracted data from the publications. CLS, SW, KB-C, EM, GD, EL, and RP synthesised the findings from the review. JB directly accessed and verified the underlying data reported in the manuscript. JB drafted the manuscript with input from CLS, EL, SW, KB-C, GF, RP, EM, GD, and AC. EC, JW, and YZ made critical comments on the emerging draft. All authors critically reviewed the final manuscript and take responsibility for its accuracy and presentation. The corresponding author attests that all listed authors meet authorship criteria and that no others meeting the criteria have been omitted. JB is the study guarantor.
Funding: JB, CLS, EC, JW, and YZ report funding from the National Health and Medical Research Council (NHRMC) for the Partnership Centre for Health System Sustainability to support the submitted work (GNT9100002). JB, EC, and JW also declare funding from NHMRC investigator grants (GNT1176620, GNT2008645, and GNT1174021, respectively) in relation to the present manuscript. The funders had no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the manuscript; or in the decision to submit the article for publication. All authors confirm that they are independent from the funder, had full access to all of the data in relation to the manuscript, and take responsibility for the integrity of the data and the accuracy of the data analysis.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/disclosure-of-interest/ and declare: financial support from the National Health and Medical Research Council (NHMRC), Australia, for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.
Transparency: The lead author and guarantor affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.
Provenance and peer review: Not commissioned; externally peer reviewed.
Dissemination to participants and related patient and public communities: Results will be disseminated using social media such as X, and LinkedIn, at international conferences, and to relevant stakeholders within healthcare in conjunction with our healthcare consumers, advisors and experts, partners and stakeholders.
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