While many countries are increasingly recognising – and responding – to the environmental impact of their health systems, many of the policies that have thus far been enacted to mitigate the greenhouse gas emissions of the health sector have reflected broader mitigation actions taken in countries, such as focussing on transitioning to renewable energy sources and improving energy efficiency in buildings. This chapter argues that there is further scope for health systems to reduce their environmental impact by changing practices in the delivery of healthcare itself, including reducing low-value and wasteful care.
Decarbonising Health Systems Across OECD Countries
Abstract
Health systems represent an important – and growing – share of greenhouse gas emissions in OECD countries. On average across OECD countries, the health sector contributed 4.4% of countries’ overall greenhouse gas emissions in 2018. The health systems of OECD countries collectively emit more greenhouse gas emissions than other highly cited sectors of the economy, such as aviation.
As a provider, hospitals represent the most important driver of health sector emissions: 30% of health sector emissions were driven by hospital care on average across OECD countries. New OECD estimates suggest that by reducing avoidable admissions and the average length of stay in hospital, countries could reduce hospital-based emissions by a quarter. In contrast, emissions associated with outpatient providers were estimated to contribute 20% of health sector emissions.
Long-term care also drives an important share of emissions. On average across OECD countries, nursing homes represented 6% of health sector emissions. This figure is almost certainly an underestimate of the true contribution of long-term care to health sector emissions, as it does not count long-term care delivered at home or in hospital settings, but only in residential care. Without changes to how long-term care is delivered, the emissions associated with ageing and long-term care will continue to rise as populations age further.
Across OECD countries, an increasing number of health systems have taken steps to measure health systems emissions. Nevertheless, the number of products and services for which emissions have been estimated remains a small fraction of the overall number of individual medical products and supplies, and there remain significant challenges in ensuring measurement approaches are harmonised and comparable across countries.
The majority of countries have reported taking steps towards reducing the health sector’s impact on greenhouse gas emissions. Some have invested important resources into measures meant to transform the environmental sustainability of their health systems, putting in place strategies, guidelines, climate change and health teams, and rules and regulations intended to embed awareness of healthcare’s environmental impact across the sector. At the same time, not all care can be substituted, and policies designed to reduce emissions must be designed carefully to ensure quality of and access to needed care are not compromised.
At the same time, majority of OECD health systems have in many cases not meaningfully begun to integrate climate change considerations into the way that healthcare is procured, delivered, and practiced. Where efforts have been undertaken to address greenhouse gas emissions, the policies that have been focussed on and scaled up have broadly aligned with broader mitigation initiatives spearheaded by governments. These policies, including promoting energy- and building-related sustainability, have often been brought into health systems as part of more comprehensive national efforts at greenhouse gas mitigation.
In contrast, the potential for reductions in greenhouse gas emissions due to changes in healthcare delivery, including in prevention, reducing the use of inappropriate care, and reducing demand for healthcare through better health outcomes, has not received a similar level of focus in health systems mitigation. There remains significant opportunity to align efforts to reduce inappropriate care with healthcare‑focussed mitigation initiatives. The most effective way to reduce emissions in the health sector is not to need care in the first place. Policies that promote reducing low-value care and waste in health systems deliver win-win outcomes for the environment by also contributing to reducing health sector emissions.
Across OECD countries, health sector emissions could be impacted – and reduced – by healthcare delivery policies that prioritised low-emissions alternatives to existing practices. Policies that prioritise better care management, primary care, and the balanced use of telemedicine could help to drive down healthcare emissions while improving health outcomes.
Four-fifths of OECD countries report that no funding for mitigation actions in the healthcare sector has been allocated. Allocating funding and scaling up the development of climate change and health teams within Ministries of Health, and across government, is critical to ensure health systems have sufficient support to transition towards more environmentally sustainable care.
A major challenge in developing climate‑responsive healthcare is that the evidence base for what works is still emerging, and measurement challenges continue to hamper the evaluation of progress. Ensuring that governments and the private sector have the tools they need to measure and track the environmental impact, including emissions, of the health sector in a comparable and harmonised way is indispensable to driving meaningful change.
Compared with some other sectors, the health system has turned its attention on its contribution to climate change relatively late. As a growing understanding of the health system’s greenhouse gas emissions has developed over the last decade, political will to take action has grown.
Nevertheless, attention to climate change mitigation within the health sector broadly lags behind the prioritisation that many health systems have given to adapting to the health consequences of climate change. Nearly four‑fifths of responding OECD countries reported that no funding has been earmarked for mitigation-related measures in their health systems (OECD, 2024[1]).
Across OECD countries, all countries have made commitments to reduce greenhouse gases at the national level, via the nationally determined contributions (NDC) set every five years and reported to the United Nations Framework Convention on Climate Change (UNFCCC). Far fewer countries have developed more concrete guidelines or strategies around reducing greenhouse gas emissions for their health sector. Among countries that have begun to develop health sector-specific strategies, many plans have been established only very recently – many in the past 2‑3 years – and are still in the process of development or implementation.
Note: UK commitment excludes emissions from international aviation and shipping.
In recent years, estimates of the health sector’s contribution to greenhouse gas emissions have been developed at the country and at the international level. While estimates differ across countries and methods, estimates have previously suggested that some 4‑7% of overall greenhouse gas emissions in OECD countries stem from the health sector. Given OECD countries spend close to 9% of their GPD on health, this would suggest that the health sector is a comparatively low emissions-intensity sector. Nevertheless, given the significance of the health sector to the economy, it nonetheless plays an important role in emissions.
New estimates from the OECD have built on the organisation’s environmentally extended Inter-Country Input-Output (ICIO) data, together with data from the OECD-WHO System of Health Accounts, to estimate emissions in an internationally comparable manner at the health sector level. This data from the OECD indicates that in 2018, greenhouse gas emissions across OECD countries averaged 4.4% of overall greenhouse gas emissions in OECD countries. On average across OECD countries, emissions associated with the health sector amounted to close to 976 million metric tonnes CO2e in 2018. Put in other terms, this would represent level of emissions close to that of the total emissions of the third-highest emitting country in the OECD, Germany.
Note: Emissions refer to demand-based emissions.
Source: OECD analysis based on environmental extension of OECD Inter-Country Input-Output database and System of Health Accounts data.
In measuring greenhouse gas emissions in the health sector and beyond, researchers have typically adopted one of two general approaches. These can be broadly categorised as taking a top-down or bottom-up approach to emissions accounting.
Bottom-up emissions analysis adopts a life‑cycle accounting approach to calculate the emissions associated with the production (including extraction of materials), transportation, use, and disposal of a product or service. This approach requires very granular detail, such as the distance between the location of production and location of use, and can be very time‑consuming to generate, particularly given the extensive number of products and services used in the health sector. One of the most extensive living repositories of healthcare‑related life cycle analyses, for example, included about 1 500 unique results as of January 2025 (Drew and Rizan, 2022[2]). Moreover, the geographic specificity needed in estimated emissions based on a life‑cycle analysis may make generalising the findings of an LCA from a specific context challenging in others.
Top-down emissions estimates generally look at emissions at a more macro level, such as at the level of the health system, region or country. They are built on extending economic input-output tables to link emissions to economic transactions within sectors and countries and offer a broader and more holistic perspective on emissions. At the same time, the top-down approach can sacrifice depth for breadth, with much less precision at more granular levels compared with a life‑cycle approach. Some analyses have combined the two approaches, complementing top-down input-output analysis with country-specific information based on life cycle assessments for certain products or services, where it is available, as in the case of estimates of NHS England’s greenhouse gas footprint.
Emissions estimates based on the two approaches can vary dramatically. A comparison of emissions estimates for medical imaging in Australia, for example, found significant differences in the emissions impact of imaging including X-rays, CT scans and MRI scans when estimated using a life‑cycle versus environmentally extended input-output approach (McAlister et al., 2024[3]).
Understanding where in the process of the production and consumption of emissions are concentrated can help policymakers to better target policies to reduce the health system’s emissions footprint. The latest OECD estimates provide new insights into the health sector’s greenhouse gas emissions, presenting a detailed picture of its environmental impact. To analyse these emissions more effectively, the total footprint was disaggregated using three complementary frameworks: by provider type, by scope, and by domestic versus international origin. Each framework organises the same emissions baseline into distinct categories, without affecting the overall total.
Hospitals and outpatient care collectively made up half of health sector emissions in 2018
Examining health sector emissions by type of provider, hospitals made up the largest share of health sector emissions, significantly higher than the emissions associated with outpatient or nursing home care. On average across OECD countries, hospitals represented 30% of health sector emissions in 2018.
Source: OECD analysis based on data from OECD Health Statistics 2025, System of Health Accounts and ICIO data.
In contrast to hospitals, outpatient care accounted for one‑fifth of health sector emissions in 2018. Given the very high number of consultations taking place in outpatient care, however, the emissions associated with a single consultation in outpatient care was substantially lower than the average emissions associated with one occupied bed day in hospital, representing less than one‑tenth of the average emissions of a hospital bed day (180 vs. 16 kg CO2‑e on average in 2018).
Source: OECD analysis based on data from OECD Health Statistics 2025, System of Health Accounts and ICIO data.
30% of health sector emissions can be traced to the electricity, gas and steam used to power health facilities and healthcare service and products
Despite growing sector-specific efforts by health professionals to mitigate the environmental impacts of the health sector, factors largely outside health decisionmaker’s authority can have an outsize influence on the level of emissions associated with health facilities and care. The available energy sources to power hospitals and facilities, for example, have an outsize impact on the emissions associated with their operations. Yet the majority of hospitals remain powered by fossil fuels in many OECD countries (Healthcare Without Harm, 2017[4]).
New OECD analysis looking at the industries of origin for health sector emissions has found that on average across OECD countries, 30% of emissions in the health sector are related to the production of electricity, gas and steam, including both for the operation of health facilities directly, but also as inputs into the production of goods used in the healthcare system.
Note: Categories based on Inter-Country Input-Output (ICIO) categorisation.
Source: OECD analysis based on data from OECD Health Statistics 2025, System of Health Accounts and ICIO data.
More than three‑quarters of emissions can be traced to health system supply chains, while half of emissions are produced outside the country where healthcare is delivered
Breaking down greenhouse gas emissions within the health sector into Scopes 1, 2 and 3, and by the source of emissions (such as hospital facilities, specific medical products, or patient and staff travel) is important in helping the health sector to understand where there are opportunities to intervene and reduce its climate impact.
One commonly used approach to understanding the emissions uses a “scope” classification developed by the Greenhouse Gas Protocol, which was established to help develop better measurement and reporting methods for the private sector. The classification covers three scopes:
Scope 1: Direct GHG emissions, which occur from sources that owned or controlled by a company. This can included emissions associated with combustion in owned or controlled vehicles, for example.
Scope 2: Indirect GHG emissions, which arise from electricity that is purchased and consumed by the company.
Scope 3: Other indirect GHG emissions, which occur in the production and transportation of goods and services used by the company, and includes the full supply chain.
Across OECD countries on average, new analysis from the OECD indicates that the vast majority – nearly 80% – of health sector emissions are related to health system supply chains. In 2018, emissions from supply chains represented an average of 78% of health sector emissions.
Source: OECD analysis based on data from OECD Health Statistics 2025, System of Health Accounts and ICIO data.
Moreover, on average across OECD countries in 2018, half of emissions found to have originated from production that occurred outside the country in which healthcare was consumed (Figure 2.6). The outsize importance of supply chains, including foreign production, in the emissions associated with healthcare underscores the importance of shifting not only the way healthcare is delivered domestically, but how healthcare supply chains operate across border (see Chapter 3 for more on supply chains).
Source: OECD analysis based on data from OECD Health Statistics 2025, System of Health Accounts and ICIO data.
At the same time, many of the interventions that the health sector must take to meaningfully reduce its greenhouse gas emissions stem from policies and actions within the purview of actors within health systems, but are peripheral to what might be considered to be health policies themselves. Some of the biggest “value” interventions for reducing health systems emissions have nothing to do with the health system per se, and are rather actions that can and are being taken across different sectors in society, such as fleet electrification or shifts towards renewable or greener energy sources.
Many of these structural changes are being driven by mitigation policies that have been set outside of the health sector, such as in commitments related to a country’s nationally defined contribution, but nevertheless have enormous potential impacts for the emissions of the health sector itself. In addition to such structural mitigation actions that can be applied to the health sector, health systems have the potential to further reduce their emissions impact via actions that target the actual approach to healthcare delivery.
The breadth of policy responses needed to reduce the climate impact of health systems requires an all-hands-on-deck approach that empowers stakeholders across the health system to take the actions necessary to meaningfully reduce greenhouse gas emissions from the health sector. This necessitates that not only clinicians, but also other decisionmakers, including healthcare administrators, policymakers, and even patients, are equipped with both the knowledge and authority to implement changes that reduce the emissions impact of the sector.
Reducing low-value care: A win-win-win for outcomes, costs and environmental impact
Breaking down emissions within the health sector by those amenable to changes in healthcare practice, OECD estimates suggest that an important share of health sector emissions could be reduced with better care delivery and focus on policies that drive down low-value care. In a scenario where avoidable hospital admissions were eliminated and the average length of stay in hospitals fell to that of the best-performing quartile, emissions associated with hospital care could be reduced by up to 25% on average across OECD countries.
Identifying low-emission alternatives to currently used medical products, reducing low-value care, strengthening care management and shifting care out of inefficient settings can all contribute to reducing emissions while also delivering on broader goals for high-performing health systems.
A number of factors may explain this. While information on the emissions contributions of different healthcare products, interventions and care pathways is growing, it remains extremely limited in the context of the breadth of the services provided by health systems, restricting the evidence base upon which to respond and act. Moreover, the role of governments in health systems across OECD countries is very significant. On average in OECD countries, nearly three‑quarters (73%) of health spending comes from public sources (OECD, 2023[5]). Many of the mitigation actions being undertaken in the health system reflect policies being driven by national (or sub-national) commitments on greenhouse gas mitigation, such as energy efficiency standards for the construction of new buildings.
Nevertheless, recent developments suggest growing momentum towards more deeply embedding environmental sustainability considerations, including reducing greenhouse gas emissions, into healthcare delivery. These include growing efforts to quantify the emissions and broader environmental impact of healthcare products, medical devices, pharmaceuticals, and entire care services and pathways, as well as developing guidelines and incentives to reduce the use of high-emitting options where lower emissions alternatives already exist.
Looking at the association between health sector emissions and measures of high performance in health systems offers an illustration of the extent to which higher emissions are – or are not – necessary or inevitable in delivering high-quality care. An analysis of health sector emissions compared to life expectancy, avoidable (preventable and treatable) mortality, quality of care, and patient satisfaction indicate that while there appears to be a clear positive relationship between health sector emissions and high performance across a number of measures, there are an important number of high-performing, low-emissions outliers that indicate quality, access, and other key dimensions of performance do not need to be compromised in exchange for lower emissions.
Note: Data for health sector emissions are expressed in per-capita terms and normalised to the OECD average. Data on life expectancy at birth is normalised to the OECD average.
Source: OECD analysis based on data from OECD Health Statistics 2025, System of Health Accounts and ICIO data.
Note: Data for health sector emissions are expressed in per-capita terms and normalised to the OECD average. Data on avoidable mortality is normalised to the OECD average.
Source: OECD analysis based on data from OECD Health Statistics 2025, System of Health Accounts and ICIO data.
Note: Data for health sector emissions are expressed in per-capita terms and normalised to the OECD average. Data on health expenditure per capita is normalised to the OECD average.
Source: OECD analysis based on data from OECD Health Statistics 2025, System of Health Accounts and ICIO data.
Comparing emissions with dimensions of strong performance in health systems indicates that there are clear examples of countries who deliver consistently strong healthcare at lower emissions levels.
Across OECD countries, sectoral decarbonisation efforts are strongly influenced by national mitigation commitments and policy. As such, ministries responsible for broader mitigation approaches – including the Ministry of Environment, Ministry of Energy, Ministry of Finance and others – often play a role in designing policies implemented by health systems. While Ministries of Health are responsible for formulating and implementing mitigation policies for the health sector in nearly 70% of countries, the Ministry of the Environment also shares this responsibility in more than three‑fifths of countries (OECD, 2024[1]).
Attention to mitigation efforts within the health sector have only recently drawn more widespread attention, and nationally co‑ordinated policymaking is still being scaled up across many countries. Within Ministries of Health, for example, just over one‑third of countries report having a team or division dedicated to mitigation policies, and nearly four‑fifths have not dedicated funding within the health budget to support emissions reduction (OECD, 2024[1]).
In recent years, a number of countries have begun setting up climate change and health units tasked with addressing and co‑ordinating both adaptation- and mitigation-related efforts within the health system.
Australia funded and established a National Health, Sustainability and Climate Unit in December 2022 within its Department of Health and Aged Care. The Unit was set up to support the development and implementation of the National Health and Climate Strategy (Australian Government Department of Health and Aged Care, 2024[6]).
In Austria, the Competence Centre Climate and Health was established in early 2022, bringing together efforts both to adapt the health system to climate change and to deliver a net zero health system (Agenda Gesundheitsförderung, 2024[7]).
In Canada, greenhouse gas emissions from the health sector are largely under the jurisdiction of provinces and territories. The Treasury Board Secretariat leads the Greening Government Strategy, which is responsible for achieving the government’s climate resilience (by 2035) and net zero (by 2050) goals (OECD, 2024[1]). The Climate Change and Health Office within Health Canada complements the strategy by supporting the Canadian health system in reducing its emissions.
In the Netherlands, a dedicated team in the Ministry of Health was established in 2019 focused on sustainability and health. It is responsible for co-ordinating the efforts of the Ministry of Health and the broader healthcare sector, as well as stimulating other ministries to take healthcare into account when making climate policy (OECD, 2024[1]). Additionally, in 2023 four sustainability coordinators were appointed in different directorates within the Ministry of Health to function as focal points on relevant subjects and opportunities to link their work with sustainability and to make sustainability an integrated part of the policy work of the Ministry.
Portugal has allocated responsibility for the implementation of the Environmental Sustainability Program of the Ministry of Health, known as ECO@SAÚDE, to the Central Administration of the Health System (ACSS) (Central Administration of the Health System, Portugal, 2021[8]). The programme focusses on monitoring the consumption of electricity, gas, water and waste production within the health system, the use of renewable energy, monitoring the sustainable renovation of health facilities owned by the Ministry of Health, and tracking and monitoring the environmental impact of government-owned vehicles (OECD, 2024[1]).
In the United Kingdom, the Sustainable Development Unit (SDU) was initially established within the National Health Service (NHS) in 2008, after the publication of the 2008 Climate Change Act, and was responsible for strengthening local efforts to promote sustainable healthcare (NHS England, 2024[9]). Following on the work of the SDU, NHS launched the Greener NHS Programme in 2022, when the Health and Care Act made the NHS the first health system in the world to legally commit to achieving a net zero health system (NHS England, 2024[10])
Many countries have not dedicated specific funding to health systems mitigation efforts
Even where governance structures to support climate change and health have been developed, funding has varied widely across countries. More than two‑thirds of OECD countries report having no dedicated financing for mitigation measures. In some, such as Belgium, funding is still available at the project level even if not included in the recurrent budget. In other countries, such as Portugal, funding is available outside of the health system – such as through the Environmental Fund and the Recovery and Resilience Plan – to support initiatives towards health systems mitigation and environmental sustainability.
A minority of countries have allocated specific funding in their health budgets to supporting the development of sustainable and low-carbon health systems, with funding often covering both aspects of health systems mitigation and climate adaptation-related resilience approaches.
In Australia, the National Climate and Health Strategy received AUD 3.4 million in funding over its first four years, with AUD 0.7 million allocated for subsequent years (Australian Medical Association, 2022[11]).
In Austria, the Competence Centre Climate and Health has been scaled up quickly since its founding in 2022, currently encompassing more than 60 staff members. The Centre was supported with EUR 24 million in funding for its first three years (2022‑2024), not including funding dedicated to specific adaptation- and mitigation-related projects. Its projects have received significant funding, including EUR 350 million allocated from the Ministry of Climate Protection through 2030 for a project co‑ordinated together with the Ministry of Health and Competence Centre to improve the energy efficiency of hospitals, rehabilitation facilities, retirement homes, and nursing facilities (Lichteneker, 2024[12]). The Competence Centre Climate and Health serves as an instructive example of how public health institutes can be brought in to support interdisciplinary work to strengthen the response to the links between climate change and health.
In Canada, Health Canada and Indigenous Services Canada were supported with CAD 55 million over five years to bolster efforts to build climate-resilient and low carbon health systems, protect people in Canada from extreme heat, and to support climate change and health adaptation for First Nations and Inuit Communities. Additional funding for climate change‑related health initiatives is available at the provincial level in some provinces.
In the Netherlands, EUR 42 million has been allocated within the budget of the Ministry of Health for 2023‑2026 to, amongst other things, support projects and initiatives that facilitate the transition towards a more environmentally sustainable health system (Ministry of Finance, Netherlands, 2025[13]).
Countries are scaling up efforts to measure the emissions impact of healthcare
While many barriers to the regular measurement of health systems emissions still exist, a growing number of countries have begun to estimate the emissions associated with health systems, or even to adopt reporting requirements in part or fully across the health system.
Reporting requirements have been adopted across health systems
In Australia, the National Health and Climate Strategy has required the government to work towards best aligning the different approaches to emissions measurement that have been adopted at the state and territorial levels by health systems. While all states and territories have begun measuring at least Scope 1 and 2 emissions from their health systems, and some also measure Scope 3, the methodologies adopted across the country have varied, often in accordance with both the targets set in the respective regions or territories, as well as with reporting requirements in the regional area. The Strategy’s call to harmonise methodologies is intended to improve the comparability across jurisdictions and across health systems, as well as to better integrate bottom-up, granular data on emissions into current estimates (Commonwealth of Australia (Department of Health and Aged Care), 2023[14]).
In New Zealand, an initiative to promote emissions reductions within the public sector, the Carbon Neutral Government Programme, was launched in December 2020 with the goal of achieving carbon neutrality by 2025. The programme requires organisations, including the Ministry of Health, to measure and report their greenhouse gas emissions, to introduce a plan for further emissions reductions, and to offset emissions starting in 2025 to ensure organisations are carbon neutral (Ministry for the Environment, New Zealand, 2023[15]). The Ministry of Health first reported their emissions in 2022 (for 2019‑2020 activities) and continue to do so on an annual basis.
In the United Kingdom, the 2022 Health and Care Act mandated service providers and commissioners within NHS England to develop ‘green’ plans in support of efforts to achieve net zero within the health system. As part of efforts to promote sustainability within the health system, NHS England began tracking and reporting its emissions in 2008, with more recent initiatives adopted that take a more detailed approach to calculating emissions, including at the local (e.g. trust or integrated care board) level. In addition to green plans and monitoring within service providers, NHS England has further launched a Net Zero Supplier Roadmap, which requires suppliers themselves to publish emissions reduction plans, report both their targets and emissions, and ultimately estimate the carbon footprint of the products that are supplied to the NHS. The net zero supplier roadmap has been introduced gradually since 2022, with full requirements in effect as of 2030, to allow suppliers enough time to adjust to the new standards (NHS England, 2025[16]).
Other countries have developed approaches to measure and report emissions at the facility level, particularly in hospitals.
In Austria, a greenhouse gas calculator is being developed by the Competence Centre Climate and Health, which will enable healthcare facilities to estimate their emissions using an approach that will enable standardised reporting across the country (OECD, 2024[1]).
In Belgium, the first baseline health sector emissions were developed and published in February 2025, following which a structured database to monitor emissions in the healthcare sector will be developed (OECD, 2024[1]; Environnement-Santé Belgique, 2025[17]).
In Canada, some provinces have adopted rules requiring public emissions disclosure for public sector organisations, including health services such as hospitals. In the province of Ontario, for example, hospitals are required to report their annual greenhouse gas emissions and energy consumption and to develop a five‑year plan for energy conservation, while in British Columbia, the Carbon Neutral Government Program requires all provincial public sector organisations to be carbon neutral and report yearly on their status through the Public Sector Organisation Climate Change Accountability Report. While the measurement of greenhouse gas emissions in Canada is largely a provincial and territorial jurisdiction, there have been more recent attempts to develop better national estimates and more consistent approaches to measurement across the country. A community of practice providing support to healthcare facilities in measuring their emissions, as well as guidelines on estimating emissions in healthcare in Canada, has been developed jointly by the Canadian Coalition for Green Healthcare together with CASCADES Canada, supported by federal funding (OECD, 2024[1]).
In the Netherlands, guidelines and roadmaps to help healthcare providers meet emissions targets and reporting requirements areset up by the Expertise Centre on Sustainable Healthcare (Expertisecentrum, Verduurzaming Zorg or EVZ) and the Environmental Platform Healthcare (Milieu Platform Zorg or MPZ) which is subsidised by the Ministry of Health. There are also plans by healthcare insurers to develop joint reporting templates to avoid overly cumbersome reporting requirements for healthcare providers.
In Norway, standards for hospital emissions measurement emerged from initiatives around environmental, social and governance (ESG) reporting. All hospitals in Norway comply with certified environmental standards (ISO 14 001) (Nordic Centre for Sustainable Healthcare, 2019[18]). The Directorate for Health has developed an online dashboard publishing information on carbon emissions and other sustainability-related information for hospitals and other specialist services, covering Scopes 1, 2 and 3 as of 2024 (Alliance for Transformative Action on Climate and Health, 2024[19]).
In Spain, a preliminary study was undertaken to measure the emissions associated with healthcare in both public and private facilities. Following the analysis of this initial benchmarking project, guidelines on the measurement of healthcare‑related emissions and on emissions reduction in health will be published (Ministry of Health, Spain, 2023[20]).
In the Netherlands, the Ministry of Health, Welfare and Sport made a commitment in 2021 at COP26 in Glasgow to support the sustainability of its health sector, including promoting the development of sustainable supply chains and measuring the environmental footprint of the healthcare sector regularly, and at least every four years.
A baseline report published in 2022 estimated that the healthcare sector represented 7% of the country’s national carbon footprint, with 80% of emissions originating from supply chains, and 40% from pharmaceuticals and chemicals used in healthcare (Steenmeijer et al., 2022[21]). It also went beyond greenhouse gas emissions to estimate the health sector’s contribution to other environmental impacts, including water use (8%), land use (7%), abiotic (non-living) resources (13%), and waste production (4%) as a proportion of the country’s overall footprint (Steenmeijer et al., 2022[21]). The publication of a second environmental footprint study of the Dutch healthcare system is expected in 2026.
Researchers at the National Institute for Public Health and the Environment (RIVM) are working to further refine the healthcare sector’s environmental footprint estimates. Building on their initial work, they are working towards improving the accuracy of top-down input-output databases and complementing the information provided in environmentally-extended input-output tables with bottom-up data from life cycle assessments and existing national databases, including data on anaesthetic gases, patient and visitor travel and mobility, and direct water consumption and waste production from facilities. Data is being collected from institutions across the government and across the healthcare sector in the Netherlands, including Statistics Netherlands, the Dutch Healthcare Authority, healthcare providers, the Ministry of Infrastructure and Waste Management, the Expertise Centre for Sustainable Care, the Netherlands Enterprise Agency, the National Healthcare Institute, and the association of emergency medical service providers. Results of the more granular analysis are intended to help to better identify “hotspots” of high emissions in the healthcare sector, as well as to monitor changes to emissions over time.
As they have worked to improve estimates of the Dutch healthcare sector’s environmental footprint, experts in the Netherlands have encountered challenges related to both data availability and transparency as well as data processing and reporting. They report that much core data remains fragmented, decentralised and non-harmonised, while different methodologies and a lack of harmonisation around data categories and terminologies has created significant challenges related to comparability in results (van Bodegraven et al., 2025[22]).
Three‑fifths of OECD countries have not put in place measurement frameworks to benchmark environmental sustainability
Benchmarking and regularly measuring emissions across and within the health system is important to measuring progress and to identifying where further improvements have the potential to be made. Yet progress towards better benchmarking current health sector emissions remains very fragmented. Even within the OECD, countries are at very different level of development when it comes to measuring the emissions associated with the health sector as a whole, and its subsectors. Life‑cycle analyses, which help to estimate the emissions associated with the life cycle of a product or service, have similarly been developed for just a fraction of the total products and services used within healthcare. Moreover, efforts to better harmonise measurement approaches across countries are still developing, making it difficult to compare and apply emissions estimates developed in one health system to others.
In Australia, the National Australian Built Environment Rating System (NABERS) helps both public hospitals and long-term care facilities understand opportunities to further reduce their emissions and to track emissions over time. Information included in the NABERS tool include energy output, water management, evaluation of waste management practices, and measures related to the comfort of the indoor environment (e.g. air quality, temperature, acoustic quality). Tools for private health facilities and hospitals are currently under development, as the development of a certification pathway for carbon neutrality for use among public hospitals.
In Canada, the Canadian Coalition for Green Healthcare has developed a Green Hospital Scorecard, allowing hospitals to evaluate their environmental performance across a range of dimensions and compare their performance to other hospitals and healthcare facilities across the country. As of 2021, 81 facilities participated in the data collection for the scorecard, which is open to community, academic, non-acute and small hospitals ( (The Canadian Coalition for Green Health Care, 2024[23])).
The Green Operating Room Barometer, a measurement toolkit to help improve the environmental sustainability in operating rooms and surgery has been developed in the Netherlands and is intended to be rolled out across all hospitals in the country. Roadmaps to measure and reduce greenhouse gas emissions have also been developed for the curative care sector and the long term care sector, partially subsidised by the Ministry of Health.
Norway has adopted both an overarching emissions mitigation target for the health sector, as well as eight more detailed sub-objectives aimed at reducing emissions and the broader environmental footprint of the health sector while improving health outcomes (South-Eastern Norway Regional Health Authority, 2025[24]).
In Sweden, annual reports on the environmental impacts of different regions include a number of measures related to the impact of the health system on the environment and on emissions, as well as policies with important health co-benefits, including healthy eating and public transportation. Metrics to track the environmental impact of healthcare include antibiotic consumption and the environmental impact of medically used gases. Cross-regional comparison is intended to improve knowledge exchange and progress towards environmental sustainability across the country (Sveriges Kommuner och Regioner, 2023[25]).
Better and more consistent measurement approaches are still lacking in many cases
Even as the number of countries undertaking emissions analyses for their health sector has increased, further work is needed to better quantify the potential environmental impact of the products, services and processes used across the health sector. Even as initiatives such as Healthcare LCA have compiled an extensive repository of life‑cycle analyses related to health products, the number of analyses that have been conducted is dwarfed by the sheer number of products and items used in healthcare.
Ensuring standardised approaches to life‑cycle analysis are adopted to best allow for cross-product and cross-country comparability is integral to this process. As countries have begun to adopt stricter reporting and measurement requirements among their suppliers, some have also begun turning to the question of helping develop better methods of estimation for the emissions associated with products.
In France, recent guidance co-published by the Ministry of the Economy, Finance and Industrial Sovereignty is intended to help establish an assessment methodology for the carbon footprint of medicines used in the sector. The guide was developed for healthcare professionals across the medicines supply chain, from manufacturers and suppliers to policymakers and clinicians, to help develop comparable and rigorous estimates of emissions using an approach that is not overly resource intensive (Ministry of the Economy, Finance and Industrial Sovereignty, France/EcovaMed, 2024[26]).
Most countries have in place energy standards applicable to the health sector – but these are often broader energy regulations, rather than designed for health systems in particular
The vast majority of OECD countries have put in place laws, regulations, policies or strategies to reduce energy-related emissions from healthcare facilities. Ninety per cent of responding countries reported that policies are in place to support energy efficiency upgrades to buildings, while two‑thirds of countries have in place initiatives that support measures to strengthen the adaptation response, including facility-level vulnerability assessments and necessary building upgrades (OECD, 2024[1]).
In most cases, the development of stricter emissions rules and support to achieve better environmental sustainability are linked to broader mitigation measures that apply across economic sectors. More than three‑quarters of countries reported having in place requirements that specifically apply to the new construction of healthcare facilities to comply with climate change‑related emissions standards. Of the countries that report such requirements, however, more than 90% report that such requirements are part of broader requirements promoting sustainability in construction, rather than specific to the health sector.
Some countries report that both health-specific and broader emissions standards have been developed that apply to the health sector.
In Australia, the Australasian Health Facility Guidelines have been developed to serve as a general guide for all standards applicable to health facilities. These include specifications on regulations and standards related to environmental sustainability, including anaesthetic gas leakage and energy efficiency standards. Some regional states and territories have also developed initiatives to promote the decarbonisation of health facilities. In the state of Victoria, for example, the Victorian Government has committed all new public hospitals to be fully electric, using 100% renewable sources of energy, by 2025. Across the state, all new healthcare buildings – regardless of their size – are required to be fully electric. Sustainability guidelines have been published by the Victorian Health Building Authority to support the development and transformation of sustainable health facilities. In addition, the federal government is in the process of updating the National Construction Code to strengthen energy efficiency, with new building requirements applicable to the healthcare sector, including the construction of hospitals. Guidelines are also being developed that target the sustainability and resilience of the long-term care sector, with the Department of Health and Aged Care in the process of creating the National Aged Care Design Principles and Guidelines, which will help inform the renovation and construction of long-term care facilities.
In Austria, EUR 350 million has been allocated to support the development of “climate‑friendly” healthcare facilities, including hospitals, outpatient clinics, rehabilitation centres, pharmacies and long-term care facilities. The project takes a holistic approach to sustainable building transformation, looking not only at structural changes to reduce greenhouse gas emissions, but the further promotion of sustainable procurement, mobility and transportation, food systems, and waste management, as well as broader awareness raising and staff training. More than 400 facilities are currently involved in the project.
In Canada, for example, the province of British Columbia published guidelines for environmental sustainability and low carbon resilience (the Low Carbon Resilience and Environmental Sustainability Guidelines for Healthcare New Construction) to help influence and inform both the construction of new healthcare infrastructure and major renovations of existing health and long-term care facilities (EES, 2024[27]). As a living document, the guideline is intended to be updated as best practices in low-carbon and environmentally sustainable healthcare construction evolve.
Denmark’s five regions published a strategy for sustainable hospitals in 2024, setting a national goal to reduce halve consumption-based CO2 emissions by 2035 (compared to a 2022 baseline) (Danish Regions, 2024[28]).
In Estonia, national targets are being set at the sectoral level (e.g. buildings, waste management, energy, agriculture, transport, oil and shale, and other processing industries and construction) to reduce greenhouse gas emissions. Sectoral targets will apply across the economy, including to health systems, once the anticipated Climate Resilient Economy Act is passed (Republic of Estonia (Ministry of Climate), 2024[29]; Estonian Public Broadcasting, 2024[30]). The development of a standardised reporting framework that would also apply to the health sector is also planned (OECD, 2024[1]).
In France, mandatory requirements related to the energy efficiency of new healthcare facilities have been in place since 2012. As of 2025, healthcare facilities are required to comply with even stricter standards, including standards around carbon emissions.
In Hungary, a Building Renovation Monitoring System is being developed to better track progress towards emissions reductions goals in public buildings. Data will be collected on the number of public buildings that have undergone energy renovations, the emissions and energy impact of these renovations, and the cost of renovations.
In Israel, standards for green hospital construction have been developed. While non-binding, they have served as a standard that has moved new building construction towards more sustainable methods.
In the Netherlands, national regulations on building sustainability have been complemented by additional guidelines and information through the Expertise Centre on Sustainable Healthcare (Expertisecentrum Verduurzaming Zorg, or EVZ), which is a joint activity of the Environmental Plaform Healthcare (MPZ) and Netherlands Organization for Applied Scientific Research (TNO) in co-operation with branch organizations who participate in the Green Deal Sustainable Healthcare. The EVZ has published guidelines on sustainable building materials and circular construction applicable to the health and care sectors (Expertisecentrum Verduurzaming Zorg, 2024[31]). Information on the website EVZ is free available for all healthcare suppliers to use. Subsidies and grants are also available for healthcare providers for making their buildings sustainable, both on regional and national level, specifically to support small and medium-size organizations.
a joint activity of the country’s hospital association, social care association, university medical centre association, and disability care association. EVZ has published guidelines on sustainable building materials and circular construction applicable to the health and care sectors (Expertisecentrum Verduurzaming Zorg, 2024[31]).
In Portugal, energy efficiency and environmental targets have been set for public health buildings, including long-term care facilities, to improve their environmental performance over time. Annual reduction targets have been set for water consumption, energy consumption, and broader materials consumption, with goals for a threshold of renewable energy consumption to be reached by 2030.
Slovenia’s technical guidelines for the construction of new medical facilities requires certain standards of energy efficiency are taken into account in new healthcare construction.
In the United Kingdom, legislation passed in 2022 enshrines into law requirements for NHS England to achieve reductions in emissions targets. The targets apply to all healthcare trusts. As of 2024, close to two‑thirds of hospitals reported making sustainability-related building upgrades, with close to half of hospitals tracking their energy consumption. Seventy per cent of trusts report measuring their greenhouse gas footprint, though about one‑third of trusts had not yet developed or implemented plans to reach the mandatory net zero goals (Hignett, 2024[32]).
Other countries have not developed specific standards or guidelines applicable to the health sector but have requirements applying to new construction across all sectors, including healthcare.
In the Czech Republic, for example, the “Construction Act” requires all new buildings, including healthcare facilities, to comply with a set of environmental standards in their construction, including an energy efficiency assessment and environmental impact assessment. While specific standards for the health system have not been developed, a number of hospitals have independently invested in energy renovations to reduce energy consumption and increase financial savings. To promote the uptake of such energy-saving renovation projects, the Ministry of Health has created an interdepartmental working group to raise awareness and encourage further adoption, particularly in large hospitals. Facilities can access subsidies for energy renovations, including from the Ministry of Environment’s “New Green Savings” programme. Twenty-six Energy Performance Contracting projects have been undertaken in the health sector, with estimated annual savings amounting to more than CZK 190 million (approximately EUR 7.7 million) (OECD, 2024[1]). Similar requirements are in place for all or public construction in other countries, including in Estonia, Greece, and Norway.
While countries are taking steps to better quantify the potential emissions impact of their healthcare sector, many are lagging behind when it comes to developing and scaling up policies that encourage the transformation of healthcare practices towards lower-emission approaches. Just over one‑third of responding OECD countries (7 of 19) report that they have in place policies – such as changes to payment systems or other incentives – to encourage the adoption of lower-emission alternatives in healthcare delivery.
Given the relatively new focus on environmental sustainability and emissions mitigation in healthcare, as well as the emerging and evolving evidence base around best practices, collaborative platforms that promote knowledge‑sharing and are flexible in adapting to new evidence can offer a useful approach to disseminating information and building momentum towards behavioural changes across the health sector.
In France, the National Agency for Supporting the Performance of Health and Medico-social establishments, or ANAP, created a national platform for best practices, accessible to all health facilities and healthcare professionals to provide information on approaches they have taken to improve the sustainable development of their facilities and practices.
Internationally, the WHO’s Alliance for Transformative Action on Climate and Health (ATACH) has as one of its major objectives to promote knowledge sharing and exchange between partners. As part of this, it has launched a “First Wins” library of best practices, with the intention of providing tangible real-life examples that will help countries move towards the implementation of the WHO’s Operational Framework for Building Climate Resilient and Low Carbon Health Systems (Alliance for Transformative Action on Climate and Health, n.d.[33]).
Some countries are taking steps to incorporate environmental sustainability into healthcare quality and outcomes frameworks
Across the OECD, a growing number of countries have begun developing health systems performance assessment (HSPA) frameworks to monitor quality and performance in their health sector. HSPA frameworks can help countries to identify the outcomes fundamental to what they conceive as high-quality, high-performing health systems, and what structural foundations and cross-cutting dimensions are critical to building a system that can achieve these goals. By providing a structure to systematically evaluate progress around the fundamental objectives of the health system, HSPA frameworks can help policymakers to better identify where health systems are performing well, where improvement is needed, and how resources can be allocated to ensure key goals are met.
Until recently, health systems performance assessment did not consider environmental sustainability as linked to important outcomes of the health system (e.g. the impact of environmental factors on health outcomes, akin to the social determinants of health, or as a dimension of health systems sustainability).
The inclusion of environmental factors into HSPA frameworks can serve to further institutionalise environmental considerations as a key dimension of health systems performance – rather than an interesting but more voluntary or optional consideration healthcare professionals can take into account given adequate resources or time. Incorporating environmental factors – and ultimately, quantifiable, regularly monitored indicators – could serve as a powerful signal by health policymakers that taking into account environmental sustainability in health systems is as important as a measure of performance as financial sustainability or other measures. To date, at least 11 OECD countries have adopted HSPA frameworks to guide the monitoring and evaluation of health systems quality. Of these, no countries have incorporated measures of environmental sustainability into their assessment frameworks.
One country, Belgium, has plans to add an environmental sustainability dimension to their framework and is currently undertaking research and preparatory work to develop the indicators that would accompany this component of the framework. Ultimately, the assessment framework is intended to encompass multiple dimensions of environmental sustainability, expanding beyond greenhouse gas emissions to include other dimensions of environmental impact. Three further countries – Australia, Czechia, and Estonia – have incorporated the environmental impacts on health into their assessment frameworks, but do not take into account environmental sustainability itself. In Australia, the Australian Commission on Safety and Quality in Healthcare is piloted an Environmental Sustainability and Climate Resilience Healthcare Module in 2024 (Australian Commission on Safety and Quality in Healthcare, 2024[34]). The module represents a pilot framework aimed at helping to strengthen health systems resilience to climate change while reducing its impact on climate change through the scale‑up of mitigation practices. The Module is intended to be implemented in parallel with other safety and quality standards in the health sector and is focussed on health services and clinical practices that have significant impacts on the environment, and on the environmental impact of healthcare organisation and delivery (e.g. waste systems or energy systems). Learnings from the pilot implementation are intended to be integrated into the release of a formal Module in 2025 (Australian Commission on Safety and Quality in Healthcare, 2024[34]).
In 2024, the OECD released a revised Health System Performance Assessment framework, intended to serve as a guide for future health systems assessment. For the first time, the revised health systems performance assessment (HSPA) framework includes reference to environmental factors within the broader health systems context (OECD, 2024[35]).
The framework recognises the many different relationships between environment and health, including the impact of various environmental risk factors on health outcomes, and the environmental impacts caused by health systems themselves. Notably, the cross-cutting pillar of sustainability encompasses not only financial sustainability, but also environmental sustainability, making reference to the health system’s greenhouse gas emissions and enough flexibility to expand out to define the health system’s environmental impact more broadly.
Source: OECD (2024[35]), Rethinking Health Systems Performance Assessment: A Renewed Framework, https://doi.org/10.1787/107182c8-en.
Bottom-up action is driving many mitigation efforts within the health sector
The lack of institutionalised, national-level policy action towards health systems mitigation in many countries does not capture the full picture of how many healthcare professionals have taken steps to better integrate environmental considerations into their healthcare delivery practice. Much action has been taken at the local (e.g. hospital or regional) level, often instigated by clinicians and other healthcare professionals, to push their healthcare facilities to adopt more sustainable methods of care practice and delivery.
Some countries have more recently begun to scale up emissions reduction initiatives that originated at more local levels. In Denmark, for example, the Central Denmark Region’s Center for Sustainable Hospitals began tracking the consumption of various medical products and waste for the hospitals in its region, communicating with clinicians in the hospitals about the consumption of high-waste and emissions products such as single‑use surgical equipment to promote behavioural changes. The experiences of the region have formed the base for the development of a country-wide Danish Regions Strategy for Sustainable Hospitals, published in 2024. In addition to a country-wide emissions reduction goal for hospitals (halving consumption-based emissions by 2035, compared to a 2022 baseline), the strategy identifies three particular areas of intervention: procurement, behavioural change and supporting a circular economy, and reducing emissions from energy, buildings and transportation (Danish Regions, 2024[28]).
Many actions taken at the national level or outside of the health sector nevertheless heavily impact the emissions associated with health systems, with energy sources and national environmental and energy regulations impacting decision making and actions within health systems. Nevertheless, there is much that can be done within health systems to further drive down emissions. Many actions that can reduce health systems-associated emissions also have positive benefits for other health systems goals, such as financial efficiency, and can be delivered without impacting quality of care or patient outcomes.
Opportunities to reduce healthcare‑associated emissions exist across a range of different domains, and actions and decisions can be taken at the micro-, meso- and macro levels by healthcare professionals across the field, including not only healthcare delivery, but also policymaking and administration.
Scaling up telemedicine
The use of telemedicine as a substitute for in-person appointments has increased dramatically in recent years, with its uptake sped up rapidly by the COVID‑19 pandemic. Between 2015 and 2021, the number of teleconsultations rose markedly across nearly all OECD countries with available data, from virtually no consultations in 2015 to 1.6 visits per person in 2022.
Source: OECD Health Statistics 2024.
As the potential for the use of telemedicine has increased, policymakers interested in opportunities to mitigate health sector’s climate impact have identified the promotion of telemedicine as a promising avenue to meaningfully reduce emissions (Purohit, Smith and Hibble, 2021[36]). For routine consultations with primary care or outpatient specialists that do not involve significant use of resource‑intensive procedures such as laboratory tests or digital scans, the largest emissions impact associated with patient visits relates to the emissions associated with patient travel to a clinic or hospital.
Studies comparing in-person medical visits with their telemedical alternatives have systematically identified lower emissions associated with the use of virtual and telephone‑based visits, compared to their in-person alternatives (Purohit, Smith and Hibble, 2021[36]). The majority of the emissions savings have been associated with reductions in patient travel to visits. A recent systematic review found a median distance to an appointment of 131 km, with a median emission of 25.6 kgCO2e (van der Zee et al., 2024[37]). An evaluation of the expansion of telemedicine in the province of Ontario, Canada during the COVID‑19 pandemic found that the scale‑up of virtual visits during the first nearly two years of the pandemic reduced carbon dioxide emissions by 545‑658 million kg by saving travel-related emissions associated with 63 million virtual appointments (Welk, McArthur and Zorzi, 2022[38]). At the same time, multiple reviews have found a very wide variation in both the distance travelled to an appointment and the associated emissions “savings” from a telemedicine alternative across the literature (Purohit, Smith and Hibble, 2021[36]; van der Zee et al., 2024[37]). Moreover, evaluations of the emissions savings associated with telemedicine do not always account for the different emissions associated with telemedical care, notably virtual visits, which can vary substantially based on the length of a consultation, the bandwidth of a connection, and how often the telemedical equipment is used (Holmner et al., 2014[39]). Even where these factors have been taken into account, however, telemedical alternatives to in-person consultations appear to significantly reduce the emissions associated with a medical visit, particularly given the important contribution of travel (by patients and providers) to the place of visit on the overall emissions of an appointment (Holmner et al., 2014[39]).
Despite the potential of telemedicine to serve as a lower-emissions alternative to in-person care, however, telemedicine will only reduce health sector emissions if telemedicine serves as a replacement for – rather than a supplement to – in-person care. Should telemedicine substitute for in-person consultations, or reduce the risk that patients miss appointments and therefore need more costly future care, they may help to reduce overall health sector emissions. However, if telemedical visits lead to additional in-person appointments, or simply supplement the same utilisation of in-person care, it could lead to further costs – in both emissions and expenditure terms – for the health system.
The impact of telemedicine on healthcare utilisation is not yet clear (OECD, 2023[40]). A recent survey of OECD countries indicates that the data on telemedicine remains fragmented across many countries, with fewer than half of responding countries reporting that they had data that would allow them to evaluate the impact of telemedicine on subsequent healthcare utilisation, including patient characteristics, the type of telemedicine service used, why telemedicine was used, and information on further care and patient outcomes (Keelara, Sutherland and Almyranti, 2025[41]).
While there is a growing recognition of the potential impact of scaling up telemedicine for reductions in health sector GHG emissions, policies to promote telemedicine have almost exclusively been pursued for other health system performance reasons, with the emissions benefits a potential additional advantage from policy changes that would be made independently of their environmental impacts.
In recent years, the number of OECD countries offering telemedicine services as an alternative to in-person visits has increased, with major policy advancements spurred by the onset of the COVID‑19 pandemic. In most countries where policies were adopted to support care continuity during the pandemic, patients have had their access to telemedicine maintained even following the end of the pandemic, though financing models are in many cases evolving following the rapid expansion of services during the crisis.
Reducing wasteful care
Across OECD countries, reducing low-value care has been a key priority for many years. While what constitutes “low-value” is necessarily subjective, with the views notably of the medical workforce and patients themselves not always in alignment, policymakers have identified a range of interventions and treatments that contribute to over-treatment, including over-testing and over-diagnosis, that could be brought down substantially without attendant impacts on overall health outcomes. Previous OECD work has looked extensively at the costs and impacts of waste in healthcare, finding that up to 20% of healthcare expenditure may be wasted in some OECD countries (OECD, 2017[42]).
Healthcare has been considered to be wasteful where “patients receive health services that fail to maximise health outcomes, given available resources, for reasons that could be avoided”. The concept of waste in care can be conceptualised into two separate components. Care can be wasteful when it causes a preventable adverse event, referring to outcomes that are both undesired and possibly lead to harm which are directly caused by the care received.
Care can also be considered to be of low value, when the benefits of the given care do not justify either the costs associated with the care, or its risks. Low value care can be ineffective when the care received has clinical outcomes that are no better or worse than lower-cost alternatives and inappropriate when interventions are delivered in certain circumstances or to certain patients where it is unnecessary or unwanted, and has no superior clinical effectiveness to alternatives. In addition, care that is clinically more effective but significantly more expensive than alternatives can also, in some circumstances, be considered to be low value in that it is poorly cost effective, leading to significantly higher costs for patients or health systems for the improvement in outcomes realised.
In recent years, the number of CT and magnetic resonance imaging (MRI) scans undertaken per capita has risen markedly across many OECD countries. OECD countries demonstrate wide variation in the rate of scans per capita. For example, MRI scans per capita increased by more than one‑third between 2015 and 2022 and vary more than 30‑fold across OECD countries. In total across OECD countries, the number of MRI scans performed in 2022 – more than 89 million – could correspond to more than 1.5 million metric tonnes of CO2e, equivalent to driving nearly 4 million miles by car.
A recent audit of the appropriateness of CT scans across seven European countries found a significant variation in the proportion of scans that were considered to be fully appropriate, ranging from less than three‑fifths (58%) in Greece to more than 85% (86%) in Denmark (European Commission, 2024[43]). Between 4‑16% of CT scans undertaken and included in the audit were considered to have been inappropriate care (European Commission, 2024[43]).
Policies to reduce the use of inappropriate MRIs and CT scans have been undertaken in a number of OECD countries, including Australia, parts of Canada, Denmark, the Netherlands, Sweden and the United Kingdom. While the objective of these policies has largely been unrelated to emissions reductions goals, and instead an outcome of efforts to reduce low-value care more broadly, effective reductions in inappropriate care can have the added benefit of further reducing the health sector’s contribution to greenhouse gas emissions. In Luxembourg, for example, a national action plan aimed at reducing the inappropriate use of medical imaging was launched in 2015 by the Ministry of Health (Santé Luxembourg, 2015[44]). Actions included developing a toolkit for doctors in French and German, as well as promoting additional training on appropriate medical imaging for clinicians and strengthening the medical justification needed for medical imaging. Two rounds of audits, in 2016 and 2023, have found that progress has been made in the appropriate use of medical imaging, with particular gains made in appropriate CT scans. Smaller improvements were observed in the use of MRIs (Health Department, Luxembourg, 2023[45]).
Moving care out of hospitals
For years, policymakers have broadly agreed that healthcare delivery remains overly focussed on in-patient hospital care, with insufficient care management and primary and outpatient care delivery leading to avoidable patient complications that require more complex interventions than necessary.
The impact of delivering care unnecessarily in high-intensity settings like hospitals on both care outcomes and costs is well established, as is the beneficial impact of strengthening primary care. Improving care continuity for patients living with chronic conditions such as diabetes and hypertension have been found to be associated with both better healthcare utilisation and lower mortality and complications, while increasing the use of multi-disciplinary teams to help manage care have been found to be associated with better outcomes for patients (Lee et al., 2021[46]; Chan et al., 2021[47]). Patients who regularly visit a primary care practitioner have been found to have both better health outcomes and significantly lower health spending than those who did not regularly seek primary care services. In the United States, analysis of patients associated with the Veterans Health Administration has found an average cost reduction of USD 721 per in-person primary care visit, with particularly large cost savings associated with sicker patients, particularly for the first in-person appointment (Gao et al., 2022[48]).
A limited number of studies have attempted to quantify the greenhouse gas emissions associated with primary care visits. In Switzerland, researchers have estimated one in-person consultation to generate 4.8 kg CO2e, with an average primary care practice generating 30 tons of CO2e annually (Nicolet et al., 2022[49]). In France¸ researchers found that the average primary care consultation in a rural region generated about 1.5 kg CO2e per visit, with annual practice emissions relatively similar (39.8 tons CO2e) to those found in Switzerland (Houziel, Prothon and Trinh-Duc, 2023[50]). In contrast, analyses in the United Kingdom have found much higher emissions associated with general practice visits, with a single appointment associated with 66 kg CO2e (Tennison et al., 2021[51]). While such differences may be partly explained by differences in practice organisation across countries – notably in patient and provider travel – differences in the analytical approach, including a bottom-up (Switzerland, France) versus mixed top-down and bottom-up analysis (United Kingdom) and the factors included (e.g. emissions associated with medical prescribing or facility construction) complicate international comparison and point to the importance of developing a feasible and standardised approach to emissions measurement across the sector. In all studies, travel associated with the appointment – including by patients, providers and medical couriers – were among the most important contributors to visit-associated emissions, pointing to the potential of telemedicine to possibly offset at least some healthcare‑associated emissions.
Inappropriately delivered care, whether delivered unnecessarily or in a suboptimal location, also has important emissions costs and implications for environmental sustainability. Across OECD countries, hospitalisations for avoidable admissions including diabetes, asthma, COPD and congestive heart failure vary significantly across countries, suggesting that in many countries, much more can be done to improve care management and avoid complications from chronic conditions that can result in hospitalisation.
Preliminary analysis from the OECD indicates that the emissions associated with avoidable hospitalisations from diabetes and congestive heart failure across 29 OECD countries could amount to as much as nearly 3 MtCO2e in 2021, equivalent to driving nearly 700 000 gasoline‑powered cars for a year.
Ensuring care is delivered in the right setting remains a major challenge across countries. Too often, patients do not receive care where they would most benefit from it, with many patients treated at facilities more intensive than their needs would necessitate, or more intensive than they would have required had they received better care management earlier. Strengthening primary care and reducing dependency on in-patient hospital-based care has been a priority of health systems for many years. With better care management and outpatient interventions delivered through primary and specialist care, many patients with chronic diseases like diabetes, asthma, COPD and cardiovascular disease could avoid being hospitalised for complications arising from their conditions.
Policies that strengthen care management and co‑ordination and increase patient visits to primary care and outpatient specialist providers can help to reduce complications and related hospitalisations among patients with chronic conditions. For many chronic conditions, countries have developed guidelines or standards for high-quality care pathways that are intended to help patients better manage their health in the community.
Training on climate and health is far from institutionalised
While surveys of health workers indicate there is a strong desire to take action on climate change, training systems have been slower to adapt to new demands for education on the intersection between climate change and health. Nearly seven in ten countries responding to the OECD Policy Survey on Climate Change and Health indicated that training is not included as part of the mandatory curriculum for medical students. Previous surveys of medical schools globally have found similarly low rates of climate change coverage in the medical school curriculum, with a survey of medical schools across 112 countries finding climate change was included in only 15% of medical school curricula (Omrani et al., 2020[52]). Moreover, even where climate change is covered in healthcare worker curriculums, training has focussed more on adaptation and the impacts of climate change on health than on health systems mitigation. A review of medical school curricula in Latin American countries found that climate change was included in the medical curriculum in just one school (Palmeiro-Silva et al., 2021[53]). A student-led Planetary Health Report Card evaluating medical schools across 18 countries found that the majority of medical schools do not perform well in providing planetary health-related content to their students (Planetary Health Alliance, 2024[54]).
Further clinical action depends on better information
In recent years, some countries have made good progress in improving the knowledge base around the environmental impact of medical products, services and procedures. Initiatives in some countries, such as climate‑oriented guidance in Choosing Wisely (Canada) and guidelines for greener surgical procedures (United Kingdom) have aimed to improve how clinicians can make informed decisions when delivering climate‑sustainable care. . In the Netherlands 12 medical scientific associations, the Federation of Medical Specialists (FMS) and the Healthcare Institute (Zorginstuut Nederland) developed the guideline ‘Sustainability in guidelines: Incorporating sustainability aspects into guideline development in the operating room’ to provide general guidance for incorporating sustainability into the revision of existing guidelines or the development of new national medical specialist guidelines in operating rooms. In France, the publication of guidelines around how developing a methodology for assessing the carbon footprint of medicines, as well as recent work to estimate the greenhouse gas impact of medical technologies, products and pharmaceuticals, has expanded the amount of information that health practitioners and policymakers have to make informed choices that move their health system onto a more sustainable path.
Even as similar initiatives take shape, however, such comprehensive environmental reviews of the health sector nevertheless remain the exception rather than the norm. Lacking a full mapping of the environmental impacts of the health system means that in many cases, clinicians and practitioners will be hampered even if they wish to move towards more sustainable care.
Moreover, ensuring that measurement approaches are harmonised, and that differences between approaches are well understood, will be important to ensure policymakers correctly interpret information about environmental impacts, including emissions, and take actions that do not inadvertently worsen the contribution of the health sector.
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