Climate change and cancer care: impacts and implications for patients and healthcare professionals
Calvin R Flynn1,a , Roselle de Guzman2,b , Olubukola Ayodele3,c , Joan H Schiller 4, Katie Lichter5,d , E Shelley Hwang6,e , Lisa Fox7,f , Gustavo Gosling8, Claire Hopkins9, Ken Rogan9, Eduardo Cazap10,g and Seamus O’Reilly
1Cork University Hospital, Wilton, Cork, Ireland
2Manila Central University – FDTMF Hospital, Metro Manila, Caloocan City 1400, Philippines
3University Hospitals of Leicester NHS Trust, Leicester, UK
4Oncology Advocates United for Climate and Health – International, Madison, WI, USA
5Department of Radiation Oncology, University of California, San Francisco, CA, USA
6Duke University Medical Center, Durham, NC USA
7The Institute of Cancer Research, ICR CTSU, 15 Cotswold Rd, London, UK
8Latin American Cooperative Oncology Group, Porto Alegre, Brazil
9Cancer Trials Ireland, Royal College of Surgeons in Ireland, 123 St Stephens Green, Dublin, Ireland
10Latin-American and Caribbean Society of Medical Oncology, Buenos Aires, Argentina
a http://orcid.org/0000-0001-5266-777X
b http://orcid.org/0000-0002-1930-9935
c http://orcid.org/0000-0003-3809-528X
d http://orcid.org/0000-0003-4136-6490
e http://orcid.org/0000-0002-8571-1148
f http://orcid.org/0009-0008-9749-3185
g http://orcid.org/0000-0001-8632-6826
h http://orcid.org/0000-0002-2887-7336
Abstract
Caring for patients with cancer is now being conducted in the era of a triple planetary crisis, which threatens our future on the planet. The impacts of this crisis are profound – disrupting cancer care due to displacement from extreme weather events, increasing cancer incidence and worsening cancer outcomes due to pollution, and threatening food and economic security due to loss of biodiversity. Clear that these changes will worsen in the coming years. The burden of these changes are not equitable, with the greatest impacts on countries that have contributed least to the crisis. While healthcare is the fifth leading cause of greenhouse gas emissions, climate awareness and activism in healthcare are low.
This paper examines the relationship between climate change and cancer care, highlighting regional disparities, environmental drivers of cancer risk, and the need for systemic adaptation. We present case studies from the Philippines, Nigeria, and Brazil each illustrating how climate-related events affect oncology delivery in vulnerable settings. We then explore how pollution, heat, and plastic use intersect with cancer risk and outcomes. Finally, we outline practical strategies and evidence-based toolkits for decarbonising cancer care across surgery, radiotherapy, medical oncology, and clinical trials. These insights, informed in part by global collaboration during London Global Cancer Week 2024, support the urgent integration of sustainability into oncology practice worldwide.
Keywords: climate change, cancer care, oncology, sustainability, global health
Correspondence to: Seamus O’Reilly
Email: seamus.oreilly@hse.ie
Published: 22/08/2025
Received: 24/02/2025
Publication costs for this article were supported by ecancer (UK Charity number 1176307).
Copyright: © the authors; licensee ecancermedicalscience. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background
Humanity now faces three interlinked threats: climate change, pollution and biodiversity loss [1]. Overuse of the planet’s existing resources now means that we are taking from (colonising) the resources needed by our families in the future [2]. Consequently, we now live and practice medicine in the era of “temporal colonialism”. This era was first recognised by the scientist Rachel Carson in her landmark publication ‘Silent Spring’, a book whose title was derived from the absence of birdsong, which normally heralds spring but was absent due to pesticide-related avian deaths [3]. In her book, she presciently wrote ‘We stand now where two roads diverge, but unlike the roads in Robert Frost’s familiar poem, they are not equally fair. The road we have long been travelling is deceptively easy, a smooth superhighway on which we progress with great speed, but at its end lies disaster’. A million copies of the book were sold before Rachel died of metastatic breast cancer in 1964.
Rachel Carson was correct. In the decades since her death, economic losses from climate change are estimated at $23 trillion due to premature mortality, healthcare expenditure and healthcare-related work loss [1]. Over 570,000 deaths have resulted from climate change-intensified weather events in the past two decades [4], while between 2016 and 2021, climate change-related events displaced over 134.1 million people, including 43.1 million children [5]. This is our new reality. The amount of carbon dioxide that would need to be removed by 2100 to limit global warming to its current 1.5oC level is equivalent to running the United States (US) energy industry in reverse for around 80 years [6].
While this Anthropocene era has seen significant gains in life expectancy, these advances have paradoxically come at great environmental cost to the environment. Modern healthcare produces the same global emissions as Africa, a continent of 1.5 billion people in 54 countries [7]. If we are to move beyond a ‘lifeboat ethic’ [8] to one of effectively reducing climate change, marked global behaviour change will be required [9], including changes in the professional and personal behaviour of our healthcare community [10–13]. A multinational survey of 4,654 healthcare professionals assessing views on climate change as a human health issue demonstrated high awareness of the health implications of climate change, but barriers existed to engagement in advocacy and education [14]. These findings, combined with the growing clinical relevance of climate change and its documented impact on cancer outcomes [15–29], underscore the urgency of climate adaptation within oncology.
This paper aims to explore the complex relationship between climate change and cancer care, highlighting the effects on healthcare systems, patient outcomes, and clinical practice. We begin with case studies from the Philippines, Nigeria, and Brazil to illustrate how climate change manifests across diverse geographic and socioeconomic settings. We then examine broader environmental threats—particularly air pollution and plastic use—before outlining evidence-based strategies for reducing the carbon footprint of cancer treatment across surgical, radiation and medical oncology. Finally, we present practical toolkits and policy frameworks to support healthcare professionals and institutions in transitioning toward more sustainable oncology practices. Insights shared during a 2024 international webinar convened by Cancer Trials Ireland, the Latin-American and Caribbean Society of Medical Oncology, Latin America Cooperative Oncology Group, and Oncologists United for Climate and Health International helped inform the structure and priorities of this paper, offering frontline perspectives and reinforcing the need for global collaboration on climate-adaptive cancer care.
Regional impacts of climate change on communities
The Philippines
The Philippines is one of the most disaster-prone countries in the world. Located on the Pacific Ring of Fire, the country is highly susceptible to seismic and volcanic risks. Its 7,000 islands sit in the middle of the world's most storm-prone region, the Northwestern Pacific Basin, which is the most active tropical cyclone basin. The Philippines experiences an average of 20 cyclones per year, with some of the most severe typhoons making landfall. Climate change is exacerbating these risks.
The country has one of the world’s longest coastlines, and rapid sea-level rise is occurring at three times the global average [30]. This adds to the vulnerability of the coastal communities that lie directly in the path of storms. Projections reveal that sea levels in the Philippines will continue to rise at a rate slightly above the global average, with an estimated increase of approximately 20 cm by the end of the 21st century [31]. Millions of Filipinos living in coastal communities are at risk, and an estimated 13.6 million people may require relocation [30]. In 2024 alone, the Philippines recorded 2.5 million internal displacements due to natural disasters [32].
The heat index in several regions of the Philippines rose above 42°C (108°F) during the dry months of 2024 as a result of global warming [33]. The highest heat index ever recorded was 55°C in Guiuan, Eastern Samar, in May 2024 [33]. The average temperature across the Philippines is projected to increase by 0.9°C–2.3°C by the mid-21st century [31].
The Philippines consistently ranks among the countries with the highest disaster risk, holding the top spot in 2024 [34]. This reflects the country’s exposure to natural hazards and its limited capacity to adapt and respond. Contributing factors include insufficient infrastructure and inadequate coping mechanisms within vulnerable communities. Healthcare infrastructure is particularly at risk from extreme weather events. It is projected that around 550 of the 2,057 hospitals in the Philippines (26.7%) could face partial or total shutdown by 2100 [35]. Many hospitals are unlikely to withstand severe weather events, such as riverine flooding, coastal inundation, and surface water flooding (Figure 1).
Figure 1. Images of family home in Philippines in 1975 and subsequently in 2020.
Nigeria
While the Philippines faces the brunt of tropical cyclones and rising sea levels, Nigeria grapples with urbanisation-driven flooding and air pollution. Although the environmental challenges differ, both countries reflect how climate change disproportionately affects low- and middle-income regions, exacerbating health inequities and straining healthcare infrastructure.
Climate change poses significant challenges for low-income countries like Nigeria, manifesting through flooding, extreme weather and pervasive air pollution. These environmental shifts threaten water quality, food security and public health. The intensification of human activities, notably industrialisation and urbanisation, has markedly increased in Nigeria, thereby exacerbating already severe weather conditions. Current projections indicate that by 2030, over 60% of Nigeria’s populace is anticipated to reside in urban areas, a demographic shift that is likely to further elevate temperatures and amplify the frequency of heatwaves, air pollution and flooding incidents [36].
The issue of flooding has been particularly acute in Nigeria, displacing more than 500,000 individuals. The Nigerian Meteorological Agency highlighted in 2022 that regions adjacent to the River Niger and Benue face heightened risks of flooding [37] (Figure 2). Additionally, the northern regions of the country have reported more than a 50% increase in rainfall, positioning them precariously for impending disasters. This has been starkly illustrated by the flooding events in Borno State in October 2024, which resulted in 300 fatalities and impacted approximately 1.2 million people [38].
Figure 2. Flooding vulnerability in Nigeria.
Moreover, the dual processes of urbanisation and industrialisation have precipitated significant air quality degradation in Nigeria, evidenced by elevated levels of particulate matter and other carcinogenic pollutants. Notably, the Niger Delta region, particularly in Port Harcourt, has reported alarming levels of black soot, primarily linked to crude oil extraction and refining activities. Several studies indicate that exposure to this pollution has been associated with deleterious health outcomes, including respiratory ailments, skin disorders and reproductive health issues, affecting over 20,000 individuals. The most concerning respiratory issues include an increase in cases of EGFR-mutated lung cancer [39, 40].
The intersection of flooding and agricultural practices further complicates the landscape, as flooding events can lead to the contamination of water sources. This concern is heightened by the escalating use of pesticides and agrochemicals, which are detrimental to infrastructure, arable land and livestock. The resultant contamination exposes communities to carcinogenic substances through both water and food sources, increasing the risk of gastrointestinal malignancies [41–43].
A survey conducted by Afrobarometer in March 2022, involving 1,600 adult Nigerians, revealed that two-thirds (66%) of the respondents are aware of the deteriorating effects of climate change on the nation. However, a dominant majority (85%) believes that the onus of addressing climate change predominantly falls upon governmental entities and developed countries [44] (Figure 3). While it is imperative for national governments to implement stringent environmental regulations, advocate for sustainable energy solutions and curtail greenhouse gas emissions, it is equally vital to promote community awareness regarding the nexus between climate change and cancer. Community-led initiatives for environmental stewardship are essential for fostering impactful responses to these multifaceted challenges.
Figure 3. Public perspectives of climate change in Nigeria.
Brazil
Like Nigeria, Brazil faces the dual crisis of climate change and environmental degradation, with extreme weather events increasingly threatening healthcare infrastructure and cancer care delivery. The catastrophic floods that swept through southern Brazil in May 2024 have left an unprecedented humanitarian and healthcare crisis in their wake. Rio Grande do Sul, a state larger than the UK, was hit hardest, with entire communities submerged, critical infrastructure destroyed and over 580,000 people displaced [45] (Figures 4 and 5). Hospitals were forced to evacuate critically ill patients by helicopter or boat, while many were left without access to chemotherapy, dialysis or life-saving medications due to the widespread collapse of transportation and supply chains [46]. The impact on cancer care was particularly severe, with oncology units closing and treatment delays putting thousands of vulnerable patients at risk [47].
Beyond immediate disruptions, the floods have compounded pre-existing health inequities. The devastation disproportionately affected marginalised communities, particularly Black and working-class populations living in high-risk urban peripheries [48]. These communities, already burdened by systemic health disparities, now face increased risks of waterborne diseases like leptospirosis and dengue, as well as food insecurity and long-term mental health consequences [46]. The loss of medical records, supply shortages and power outages have further compromised continuity of care, placing cancer patients at heightened risk. Addressing the psychological toll of climate disasters is critical, as recent research highlights the importance of trauma-informed care and mental health interventions for affected populations [49].
Despite years of warnings from climate scientists, insufficient infrastructure investments, environmental policy rollbacks and weak urban planning left Brazil unprepared for such an event. The Lancet Countdown Latin America report highlights gaps in climate adaptation policies at the city level [50], which may have contributed to challenges in coordinating emergency response efforts in Porto Alegre and other affected areas.
To build resilience in cancer care, Brazil must urgently integrate climate adaptation into health policy. Disaster preparedness plans tailored to oncology, strengthened supply chains and regional coordination strategies are essential to maintaining care continuity during extreme weather events. The National Comprehensive Cancer Network Framework for Resource-Stratified Guidelines provides a model for prioritising oncology services in resource-constrained settings, helping to safeguard cancer patients amid climate disasters [51]. Implementing such frameworks within national disaster response plans will be critical in protecting vulnerable populations from the accelerating threats posed by climate change.
Figure 4. Aerial view of flooding in Porto Allegre May 2024.
Figure 5. Impact of flooding on critical infrastructure preventing access to care.
Interaction of climate change, air pollution and cancer
Beyond localised flooding and extreme weather events, climate change drives widespread environmental degradation, with air pollution emerging as a leading global health threat. This intersection of climate change, pollution and public health has profound implications for cancer incidence and outcomes, affecting vulnerable populations worldwide.
In 2021, the World Health Organisation called climate change ‘the single biggest health threat facing humanity’ [52]. A joint editorial across 230 publications, including the New England Journal of Medicine and The Lancet stated that the health effects of climate change are ‘catastrophic’ [53], while the UN Secretary-General Antonio Guterres warned that humanity has ‘opened the gates of hell’ [54]. The Lancet Commission on Public Health emphasised that ‘Pollution... is an existential threat to human health and planetary health’ [55]. However, climate change is often perceived by the public as an environmental, political or social issue. Overlooked is the significant impact of climate change and air pollution on healthcare delivery, outcomes and cancer care specifically.
Air pollution and climate change are two sides of the same coin: they are both driven by the burning of fossil fuels. These fossil fuels emit so-called greenhouse gases (CO2, nitrogen dioxide, methane and hydrofluorocarbons, among others) that accumulate in the troposphere, trapping solar radiation and raising global temperatures. Over the past 150 years, greenhouse gas emissions have risen exponentially, correlating with increasing global temperatures. This warming trend is associated with extreme heat, severe weather events, shifts in vector ecology (fleas, mosquitoes and ticks), rising sea levels and water and food shortages [56, 57]. These changes disproportionately affect poorer, underserved communities that contribute the least to the problem.
While the immediate impacts of climate change include displacement and infectious disease, its longer term consequences, such as air pollution and disruptions to healthcare, significantly elevate cancer risks. This makes climate change not only an environmental crisis, but also a growing oncological concern.
How do these environmental changes affect cancer patients? Cancer patients are particularly vulnerable to extreme heat and severe weather events such as hurricanes and cyclones, which disrupt healthcare access. Changes in vector ecology may lead to pandemics and infectious diseases, while food and water contamination resulting from droughts, floods and sea-level rise can cause malnutrition and gastrointestinal diseases [56].
Air pollution, particularly fine particulate matter (PM2.5), is classified as a Group 1 carcinogen by the International Agency for Research on Cancer. PM2.5 particles penetrate the lung’s terminal bronchioles, causing localised inflammation (leading to asthma and lung cancer) and can translocate into the bloodstream, triggering systemic inflammation linked to cardiovascular and neurological diseases. Notably, PM2.5-induced lung cancer affects non-smokers and emerging evidence links it to breast and other cancers [58]. Air pollution from wildfires, which are increasing in intensity and frequency due to climate change, also contains PM2.5 that is more toxic than ambient pollution [59].
Modern healthcare relies heavily on plastics, considered the signature material of the contemporary era [60]. However, plastic manufacturing accounts for 8% of global oil production, as oil serves as both a feedstock and fuel. This process disproportionately affects workers in plastics manufacturing, who experience higher cancer rates, and children in nearby communities, who suffer from elevated leukemia rates [61]. Although healthcare represents 2% of global plastic consumption, this figure is rising by 6% annually. The COVID-19 pandemic and future global health crises will likely accelerate this trend. Less than 10% of plastics are recycled globally, contributing to the accumulation of over 6 gigatons of plastic waste since 1950. Half of all plastics ever produced were made since 2002. Plastics, resistant to degradation, persist in ecosystems and biological systems as macro- and microplastics, with known carcinogenic potential [62–64]. Plastics, while vital in modern medical equipment and drug delivery, present dual risks. Not only do they contribute to environmental degradation, but the leaching of plastic byproducts into water and food supplies introduces endocrine disruptors and carcinogens, posing long-term cancer risks.
Furthermore, marine plastic pollution further threatens ocean ecosystems, which are critical for food, oxygen, livelihoods and global health [65]. Reducing reliance on fossil fuels and single-use plastics within healthcare settings can significantly mitigate both environmental harm and cancer risks, highlighting the responsibility of the medical community in combating climate change at its source.
As demonstrated by regional disparities in Brazil, Nigeria and the Philippines, the disproportionate effects of climate change on vulnerable communities underline the need for systemic mitigation strategies across oncology disciplines. A range of tools has been developed to address the environmental harms and impact of healthcare, including in cancer care, with a focus on practical, scalable solutions for reducing carbon emissions in clinical and operational settings. These tools provide evidence-based approaches that enable healthcare teams to integrate sustainability into oncology practices effectively [66, 67].
These resources have focused on the principles of reduce, reuse, recycle, rethink and research. Table 1 highlights a selection of resources in this area, including curated web-based portals that offer guidance on implementing sustainable practices across healthcare institutions.
Surgical oncology
Surgical oncology procedures are central to the treatment of cancer but have undeniable and growing impacts on environmental sustainability. In the US, the healthcare sector accounts for 8.5% of all greenhouse gas emissions, with up to one-third generated in the perioperative environment [68]. From the production and disposal of surgical equipment, to the energy and resources required for routine operating room functions, the environmental footprint of cancer surgery spans multiple sectors. Additionally, biomedical waste from the disposal of tissues, organs and other biological materials, as well as the use of anesthetic gases (e.g., nitrous oxide and desflurane), contributes significantly to greenhouse gas emissions, with a far greater global warming potential than carbon dioxide.
These wide-ranging effects present an opportunity to address climate change within the perioperative space. A scoping review highlights various initiatives that surgeons and surgical staff can implement, including reducing perioperative greenhouse gas emissions, enhancing waste management, integrating sustainability training and education, and expanding recycling programs [69]. Operating room committees have successfully developed and executed sustainability procedures, demonstrating the feasibility of reducing perioperative waste within a short timeframe.
Table 1. Resource toolkits.
Further research is necessary to fully understand the environmental impact of these initiatives and to establish metrics that enable ongoing assessment of their effects on patient outcomes, cost and sustainability. There is significant potential to leverage motivated stakeholders and explore opportunities to reuse drugs, supplies and equipment, facilitating long-term reductions in the environmental footprint of surgical procedures without compromising the quality of care for patients and providers.
Radiation oncology
Several tools have been developed to address the environmental harms and impact of healthcare, including in radiation oncology, with a focus on practical, scalable solutions for reducing carbon emissions in clinical and operational settings. One such tool is the Network Greener Calculator, introduced in recent research published in the Journal of Clinical Oncology [70]. This calculator was developed by analysing data from nearly 140,000 international attendees at the American Society of Clinical Oncology (ASCO) Annual Meetings, enabling conference organisers and participants to estimate emissions associated with travel and in-person attendance. The tool compares these emissions with those of virtual or hybrid conference formats. Beyond reducing carbon footprints, the calculator also addresses diversity and inclusivity by promoting equitable access to professional development opportunities that virtual and hybrid formats can provide, particularly for underrepresented or geographically remote participants [70, 71].
Another resource is the NorCal Procedural (Brachytherapy) Waste Audit Toolkit, created by Stanford Radiation Oncology resident Dr. Claire Baniel [72]. This open-access toolkit, hosted on a shared Google Drive platform, allows oncology departments to quantify, track and reduce waste associated with cancer procedures, including brachytherapy. By conducting detailed waste audits, healthcare providers can gather data on material usage and waste generation, which can then inform policy changes and improve clinical practices [73]. Early findings from these audits demonstrate practical benefits, including cost savings and reduced environmental impact, supporting more sustainable procedural oncology practices.
Building on these advancements, an External Beam Radiation Therapy Environmental Impact Calculator is under development, inspired by research published in The Lancet Oncology [74]. This predictive nomogram maps the carbon footprint of various treatment pathways, such as hypofractionation, and identifies opportunities to reduce emissions [75]. The tool serves dual purposes: providing clinicians with actionable data to inform sustainable decision-making and educating patients about the environmental impact of different care options. By enabling informed discussions between patients and providers, especially in cases of treatment equipoise, the tool fosters a patient-centered approach to sustainable cancer care.
Together, these tools represent significant advancements in decarbonising cancer care. They equip oncology teams with the resources needed to align high-quality care delivery with environmental stewardship, thus advancing both patient outcomes and global sustainability goals.
Clinical trials
While radiotherapy contributes to healthcare emissions, clinical trials represent another significant area where sustainable practices can yield substantial environmental benefits. Clinical trials are essential to the development of new cancer treatments and the advancement of medical knowledge. However, clinical trials also contribute to healthcare greenhouse gas emissions. Adshead et al [76] estimated the contribution of clinical trials to be approximately 27.5 million tones CO2e, comparable to the greenhouse gas emissions of a country the size of Bangladesh.
Tools are becoming available to quantify the impact of trials, including guidance on carbon foot printing of clinical trials [77], and data highlighting common hotspots in publicly funded [78] and industry trials [79, 80]. Work is also underway to develop digital toolkits for the calculation and sharing of carbon footprinting data in both the private and public sector, which are intended to make the calculations easier and help encourage uptake. Although much work remains to make the consideration, quantification and reduction of the carbon footprint of clinical trials routine practice, initiatives such as the Concordat for the Environmental Sustainability of Research and Innovation Practice [81] in the public sector and the Sustainable Markets Initiative [82] for the pharmaceutical industry are fostering change.
Collaboration across public sector trialists, research funders, the pharmaceutical industry, healthcare systems, regulatory bodies, patients and the public in the UK and internationally will be critical to driving consistent and coordinated change. While this complex program evolves, it is essential to raise awareness of the resources and guidance already available to reduce the environmental impact of clinical trials. These include the NIHR’s Carbon Reduction Guidelines [83], the UK CRC Greener Monitoring Guidance [84] and the MRC-NIHR TMRP Greener Trials Group [85].
Medical oncology
For medical oncology, the most significant sustainability touch point is the prescription of systemic anticancer therapy (SACT) [86]. In an assessment of 300 medical oncology protocols from Ireland’s National Cancer Control Program, over 1,200 sustainability touchpoints were identified. These included the use of dose banding, vial sharing and telemedicine to reduce travel. For instance, the carbon footprint of administering one gram of paracetamol orally is 68-fold lower than administering the same dose intravenously in glass packaging [87]. These estimates exclude additional equipment, such as giving sets and associated complications like phlebitis [88], increased plastic waste [89] and the environmental impact of pharmaceutical ingredients [90].
In medicine, low-value, unnecessary care accounts for 6%–8% of healthcare spending [91–93]. A 2017 survey of US physicians reported that 20% of overall medical care was unnecessary, including 25% of tests [94]. Movements like Choosing Wisely and Common Sense Oncology aim to reduce overtreatment, emphasising patient engagement to drive de-prescribing and de-escalation strategies [95, 96]. Overtreatment often results from evolving care standards, reimbursement systems that reward higher volumes, lack of multidisciplinary care and litigation concerns [97, 98]. In patients with metastatic disease, overtreatment at the end of life correlates with poorer quality of death [99], in-hospital mortality and higher healthcare costs [99, 100]. As a result, 30-day mortality post-SACT is now used as a key performance indicator [101]. Early referrals to palliative care are associated with less aggressive end-of-life care [102, 103], improved overall survival and quality of life [104], reduced financial burdens and lower climate impact [105, 106].
Both ASCO and the European Society of Medical Oncology (ESMO) have developed validated frameworks – the ASCO value framework and the ESMO Magnitude of clinical benefit scale – to evaluate the efficacy, toxicity and quality of life implications of anticancer therapies [107, 108]. Current prescribing practices are often linear, leading to significant drug wastage. In the US, drug wastage accounts for 4%–18% of all cancer drug spending, with mitigation strategies reducing spending by up to 17% [109–111]. For oral SACT, 25%–41% of patients report drug wastage [112–115], and among those who discontinue treatment unexpectedly, 46%–85% are left with unused doses [116]. In a Dutch study, unopened packages had a median value of €2,600 per patient [116]. Stewardship programs, modelled after antimicrobial stewardship, could be instrumental in addressing this issue [117–119].
Attributable risk factors contribute to 40% of cancer diagnoses [120]. Prioritising health promotion, screening and prevention yields both health and climate benefits. Dietary modification, for example, plays a significant role. Food systems contribute a third of global anthropogenic greenhouse gas emissions [121]. High meat consumption negatively impacts both planetary and human health through greenhouse gas emissions, water pollution and the carcinogenicity of processed meats [122]. Shifting to plant-based diets offers benefits for both health and the environment [123].
Conclusion
The intersection of climate change and oncology presents a dual challenge: sustaining equitable, high-quality cancer care while mitigating environmental harm. As demonstrated by global disparities and regional case studies, vulnerable populations bear the heaviest burden. The aim of the current paper was to highlight the existing significant suffering experienced globally by patients (Figure 6) and the disparate challenges faced by those caring for them, and the tools available for healthcare workers in reducing the environmental impact of how we practice.
While the environmental tragedies outlined can serve as trigger events in which perception of climate risk and the need to integrate sustainability measures is more favourably viewed, they are not sufficient by themselves [124]. It has been long understood by both behavioural scientists and healthcare professionals that even highly motivated people often do not engage with actions that are consistent with their motivations. Removing or reducing the barriers that make the recommended action difficult facilitates engagement [14]. Studies of clinical trialists have demonstrated that finance, training and resourcing were identified as barriers and facilitators to climate engagement [24]. Similarly, a study of climate-engaged physicians in Canada highlighted the role of education and translational supports to guide climate impact reduction strategies in healthcare [125]. At Cancer Trials Ireland, a climate change charter has been developed by staff and patients to provide a toolkit for sustainability integration, including additional organisational touchpoints such as pension providers [67].
The resources listed in Table 1 provide a comprehensive review of some additional available toolkits, educational and literature resources. In the lifetime of the writers of this paper, cancer care has been transformed. Motivated by patient suffering, this transformation has occurred through developing multidisciplinary care pathways, through research and care pathway development. We have benefited from learning the languages of patient participation and involvement, of translational medicine, of digital technologies, among others. In an analogous manner, our community needs to engage in both climate change activism and climate change mitigation to both prevent cancer development, increase resilience in our system and a goal of moving all cancer care enterprises to net zero. Contemporaneous medical [126–129] and scientific [130–135] studies all highlight the profound impact that our triple planetary crisis has and will have, on how we live and how we practice. In March 2025, the World Meteorological Association noted that 2024 was the first calendar year to be more than 1.50C above the preindustrial era, with some of the consequences becoming irreversible over hundreds if not thousands of years [136]. Learning the language of planetary health and integrating it into how we care for patients is central to addressing this crisis if we are to continue to maintain and improve cancer outcomes in all of our communities.
Figure 6. Challenges for patients with cancer in the climate change era.
Acknowledgment
The authors are grateful to Afrobarometer for allowing them to publish their infographics in this paper.
This paper is based on a webinar conducted during London Global Cancer Week 2024 and available at bit.ly/LGCW2024
Conflicts of interest
No conflicts of interest to declare.
Funding
No funding received for this study.
Author contributions
Conceptualisation: SOR, JS, ESH, EC.
Data Curation: n/a.
Formal Analysis: n/a.
Investigation: n/a.
Methodology: all authors.
Project Administration: CF, CH, KR, EC, SOR.
Resources: CH, KR.
Software: CH, KR.
Supervision: SOR, CH, KR.
Validation: all authors.
Visualisation: all authors.
Writing-Original: CF, RDG, OA, JHS, ESH, LF, GG, SOR.
Writing – review and editing: all authors.
Graphics: SOR under licence to biorender.
References
1. Nordeng Z, Kriit HK, and Poltimae H, et al (2024) Valuation and perception of the costs of climate change on health Scand J Public Health 53 14034948241247614
2. Van Reybrouck D (2024) Revolusi: Indonesia and the Birth of the Modern World (London: The Bodley Head)
3. Carson R (2000) Silent Spring: Penguin Modern Classics
4. Lee G (2024) Climate Change Intensified Weather Events Causing Over 570,000 Deaths (Raidió Teilifís Éireann)
5. The Lancet Planetary Health (2023) Weathering child displacement Lancet Planet Health 7(11) e874 https://doi.org/10.1016/S2542-5196(23)00236-X PMID: 37940206
6. (2024) Don't overshoot: why carbon dioxide removal will achieve too little, too late Nature 634(8033) 265 https://doi.org/10.1038/d41586-024-03266-9 PMID: 39385057
7. Weadick CS, Keogh RJ, and Carroll HK, et al (2023) Climate toxicity: an increasingly relevant clinical issue in cancer care J Cancer Policy 35 100410 https://doi.org/10.1016/j.jcpo.2023.100410 PMID: 36773799
8. Tuana N (2020) From a lifeboat ethic to anthropocenean sensibilities Environ Philos 17(1) 101–123 https://doi.org/10.5840/envirophil202011791
9. Vlasceanu M, Doell KC, and Bak-Coleman JB, et al (2024) Addressing climate change with behavioral science: a global intervention tournament in 63 countries Sci Adv 10(6) eadj5778 https://doi.org/10.1126/sciadv.adj5778 PMID: 38324680 PMCID: 10849597
10. Bernicker E, Averbuch SD, and Edge S, et al (2024) Climate change and cancer care: a policy statement from ASCO JCO Oncol Pract 20(2) 178–186 https://doi.org/10.1200/OP.23.00637
11. Braithwaite J, Pichumani A, and Crowley P (2023) Tackling climate change: the pivotal role of clinicians BMJ 382 e076963 https://doi.org/10.1136/bmj-2023-076963 PMID: 37770093
12. Sergeant M and Hategan A (2023) What healthcare leadership can do in a climate crisis Healthc Manage Forum 36(4) 190–194 https://doi.org/10.1177/08404704231157035 PMID: 36951255 PMCID: 10291484
13. Or Z and Seppanen AV (2024) The role of the health sector in tackling climate change: a narrative review Health Policy 143 105053 https://doi.org/10.1016/j.healthpol.2024.105053 PMID: 38537397
14. Kotcher J, Maibach E, and Miller J, et al (2021) Views of health professionals on climate change and health: a multinational survey study Lancet Planet Health 5(5) e316–e323 https://doi.org/10.1016/S2542-5196(21)00053-X PMID: 33838130 PMCID: 8099728
15. Reuters (2023) Canada Wildfires: What are the Causes and When Will it End?
16. Debone D, Tavella RA, and Colombo AL, et al (2024) Is It Time to Build an Ark? The Reality of Climate Change in One of the Worst Climate Tragedies in Brazil (Preprintsorg)
17. Fox M (2024) “The Future is Dark”: Brazilian Business Shattered by Floods [www.aljazeera.com]
18. Canuto R (2024) Flooding and climate denialism are harming millions of people in southern Brazil BMJ 386 q1519 https://doi.org/10.1136/bmj.q1519 PMID: 38986544
19. Deivanayagam TA and Osborne RE (2023) Breaking free from tunnel vision for climate change and health PLOS Glob Public Health 3(3) e0001684 https://doi.org/10.1371/journal.pgph.0001684 PMID: 36963098 PMCID: 10021701
20. Owens B (2024) 'Fire clouds' from super-hot wildfires are on the rise as Earth warms Nature https://doi.org/10.1038/d41586-024-02530-2
21. Gilford DM, Giguere J, and Pershing AJ (2024) Human-caused ocean warming has intensified recent hurricanes Environ Res Climate 3(4) 045019 https://doi.org/10.1088/2752-5295/ad8d02
22. Cortez BN, Pines GF, and Avila-Diaz A, et al (2023) Nonstationary extreme precipitation in Brazil Hydrological Sci J 67 1372–1383 https://doi.org/10.1080/02626667.2022.2075267
23. Elia MR, Toygar I, and Tomlins E, et al (2024) Climate change, climate disasters and oncology care: a descriptive global survey of oncology healthcare professionals Support Care Cancer 32(11) 764 PMID: 39485605
24. O’Reilly S, Griffiths J, and Fox L, et al (2024) 295P Climate change impact and sustainability: a survey of Breast International Group (BIG) members ESMO Open 9 103352 https://doi.org/10.1016/j.esmoop.2024.103352
25. Nogueira LM, Sahar L, and Efstathiou JA, et al (2019) Association between declared hurricane disasters and survival of patients with lung cancer undergoing radiation treatment JAMA 322(3) 269–271 https://doi.org/10.1001/jama.2019.7657 PMID: 31310288 PMCID: 6635902
26. Bennet G (1970) Bristol floods 1968. Controlled survey of effects on health of local community disaster Br Med J 3(5720) 454–458 https://doi.org/10.1136/bmj.3.5720.454 PMID: 5454327 PMCID: 1701441
27. Man RX, Lack DA, and Wyatt CE, et al (2018) The effect of natural disasters on cancer care: a systematic review Lancet Oncol 19(9) e482–e99 https://doi.org/10.1016/S1470-2045(18)30412-1 PMID: 30191852
28. Huse E, Malone J, and Ruesch E, et al (2020) An analysis of hurricane impact across multiple cancers: accessing spatio-temporal variation in cancer-specific survival with Hurricane Katrina and Louisiana SEER data Health Place 63 102326 https://doi.org/10.1016/j.healthplace.2020.102326 PMID: 32543419
29. Cantor D, Roberts B, and Swartz J (2024) Health of people who are displaced in their own countries is a neglected global crisis Nature 635(8039) 548–550 https://doi.org/10.1038/d41586-024-03760-0 PMID: 39562814
30. Climate Change Commission National Integrated Climate Change Database and Information Exchange System (NICCDIES). Climate Change Impacts [https://niccdies.climate.gov.ph/climate-change-impacts]
31. Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) PAGASA, 2018: Observed and projected climate change in the Philippines [https://icsc.ngo/wpcontent/uploads/2019/07/PAGASA_Observed_Climate_Trends_Projected_Climate_Change_PH_2018.pdf]
32. Internal Displacement Monitoring Centre (IDMC) Global Report on Internal Displacement (GRID) 2024 [https://www.internal-displacement.org/global-report/grid2024/]
33. Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) PAGASA Homepage [https://www.pagasa.dost.gov.ph/]
34. Reliefweb World Risk Report 2024: Focus on Multiple Crises [https://reliefweb.int/report/world/worldriskreport-2024-focus-multiple-crises]
35. XDI 2023 XDI Global Hospital Infrastructure Physical Climate Risk Report [https://xdi.systems/news/2023-xdi-global-hospital-infrastructure-physical-climate-risk-report]
36. Climate Champions Nigeria’s Cities are at Severe Risk From Climate Change. Time to Build Resilience and Fast [https://climatechampions.unfccc.int/nigerias-cities-are-at-severe-risk-from-climate-change-time-to-build-resilience-and-fast/]
37. Science Nigeria NiMet Warns Against High Rainfall, Flooding in September [https://sciencenigeria.com/nimet-warns-against-high-rainfall-flooding-in-september/]
38. UNOCHA (2024) Nigeria: Floods-Situation Report No. 3 [https://www.unocha.org/publications/report/nigeria/nigeria-floods-situation-report-no-3-15-october-2024]
39. Democracy Moves The Damage Caused by Soot in River State, Nigeria [https://www.democracymoves.org/democracy-in-action/the-damage-caused-by-soot-in-river-state-nigeria#:~:text=In%202019%20report%20based%20on,other%20life%2Dthreatening%20medical%20conditions]
40. Onwuna DB (2024) Toxicity of soot against microorganisms isolated from artisanal crude oil refining sites in the Niger delta Asian Sci Bull 2(2) 166–173 https://doi.org/10.3923/asb.2024.166.173
41. The Conversation Pesticides are Harming Nigeria: It’s Time to Update the Law [https://theconversation.com/pesticides-are-harming-nigeria-its-time-to-update-the-law-207050]
42. World Food Programme Economic Hardship, the Climate Crisis and Violence in the Northeast Projected to Push 33.1 Million Nigerians into Food Insecurity in 2025 [https://www.wfp.org/news/economic-hardship-climate-crisis-and-violence-northeast-projected-push-331-million-nigerians#:~:text=Other%20major%20factors%20driving%20food,1%20billion%20in%20economic%20losses]
43. Otorkpa OJ (2017) Health impact of the indiscriminate use of herbicides in Nigeria Texila Int J Public Health 5(1) 33–40 https://doi.org/10.21522/TIJPH.2013.05.01.Art004
44. Afrobarometer Nigeria Climate Change Country Card [https://www.afrobarometer.org/publication/nigeria-climate-change-scorecard/]
45. Casa Militar Defesa Civil RS Defesa Civil atualiza balanço das enchentes no RS - 20/5, 12h [https://defesacivil.rs.gov.br/defesa-civil-atualiza-balanco-das-enchentes-no-rs-20-5-12h].
46. Machado GP (2024) Floods in south Brazil: more than an environmental crisis Lancet 404(10447) 24–25 https://doi.org/10.1016/S0140-6736(24)01024-9 PMID: 38944047
47. Baggio L, Ortiz GX, and Fischer CC (2024) Challenges and strategies to mitigate the impacts of climate disasters on oncology treatments: lessons learned from the May 2024 flood in Rio Grande do Sul Rev Bras Cancerol 70(3) e-004935
48. Borde E, Camelo LV, and Pilecco FB (2024) What the tragic floods in Southern Brazil tell us about health-centered climate-resilient development in Latin American cities Lancet Reg Health Am 35 100817 PMID: 38988453 PMCID: 11234151
49. Nature Podcast (2024) How to Recover From the Trauma of a Climate Disaster [Internet] (Podcast) [https://podcasts.apple.com/ie/podcast/nature-podcast/id81934659?i=1000675057670]
50. Hartinger SM, Palmeiro-Silva YK, and Llerena-Cayo C, et al (2024) The 2023 Latin America report of the Lancet Countdown on health and climate change: the imperative for health-centred climate-resilient development Lancet Reg Health Am 33 100746 PMID: 38800647 PMCID: 11117061
51. Carlson RW, Scavone JL, and Koh WJ, et al (2016) NCCN framework for resource stratification: a framework for providing and improving global quality oncology care J Natl Compr Canc Netw 14(8) 961–969 https://doi.org/10.6004/jnccn.2016.0103 PMID: 27496112
52. World Health Organization (2021) COP26 Special Report on Climate Change and Health: The Health Argument for Climate Action
53. Atwoli L, Baqui AH, and Benfield T, et al (2021) Call for emergency action to limit global temperature increases, restore biodiversity, and protect health N Engl J Med 385(12) 1134–1137 https://doi.org/10.1056/NEJMe2113200 PMID: 34491006
54. Ramirez R UN Chief Warns ‘Humanity has Opened the Gates to Hell’ as he Convenes World Leaders for Climate Summit 2023 [https://edition.cnn.com/2023/09/20/world/unga-climate-summit-guterres]
55. Landrigan PJ, Fuller R, and Acosta NJR, et al (2018) The Lancet Commission on pollution and health Lancet 391(10119) 462–512 https://doi.org/10.1016/S0140-6736(17)32345-0
56. Pappas G (2024) A more common enemy. How climate change spreads diseases and makes them more dangerous Bull At Sci [https://thebulletin.org/2024/10/a-more-common-enemy-how-climate-change-spreads-diseases-and-makes-them-more-dangerous/]
57. Brown V (2024) A rising danger in the arctic Bull At Sci [https://thebulletin.org/2024/11/a-rising-danger-in-the-arctic-microbes-unleashed-by-climate-change/]
58. White AJ (2025) Growing evidence for the role of air pollution in breast cancer development J Clin Oncol 43(3) 244–247 https://doi.org/10.1200/JCO-24-01987
59. Aguilera R, Corringham T, and Gershunov A, et al (2021) Wildfire smoke impacts respiratory health more than fine particles from other sources: observational evidence from Southern California Nat Commun 12(1) 1493 https://doi.org/10.1038/s41467-021-21708-0 PMID: 33674571 PMCID: 7935892
60. Landrigan PJ, Raps H, and Cropper M, et al (2023) The Minderoo-Monaco commission on plastics and human health Ann Glob Health 89(1) 23 https://doi.org/10.5334/aogh.4056 PMID: 36969097 PMCID: 10038118
61. Seewoo BJ, Goodes LM, and Thomas KV, et al (2024) How do plastics, including microplastics and plastic-associated chemicals, affect human health? Nat Med 30(11) 3036–3037 https://doi.org/10.1038/s41591-024-03287-x PMID: 39379706
62. Li C, Gillings MR, and Zhang C, et al (2024) Ecology and risks of the global plastisphere as a newly expanding microbial habitat Innovation (Camb) 5(1) 100543
63. Swanton C, Bernard E, and Abbosh C, et al (2024) Embracing cancer complexity: hallmarks of systemic disease Cell 187(7) 1589–1616 https://doi.org/10.1016/j.cell.2024.02.009 PMID: 38552609 PMCID: 12077170
64. Li S, Keenan JI, and Shaw IC, et al (2023) Could microplastics be a driver for early onset colorectal cancer? Cancers (Basel) 15(13) 3323 https://doi.org/10.3390/cancers15133323 PMID: 37444433 PMCID: 10340669
65. Landrigan PJ, Stegeman JJ, and Fleming LE, et al (2020) Human health and ocean pollution Ann Glob Health 86(1) 151 https://doi.org/10.5334/aogh.2831 PMID: 33354517 PMCID: 7731724
66. Swiecki-Sikora AL, Becker MV, and Harbin LM, et al (2024) Environmental sustainability in gynecologic oncology Gynecol Oncol Rep 55 101499 https://doi.org/10.1016/j.gore.2024.101499 PMID: 39308902 PMCID: 11416650
67. O'Reilly S, Lynch E, and Hwang ES, et al (2024) Climate therapy: sustainability solutions for breast cancer care in the Anthropocene era Clin Breast Cancer 25 198–213 https://doi.org/10.1016/j.clbc.2024.11.010 PMID: 39668009
68. Eckelman MJ, Huang K, and Lagasse R, et al (2020) Health care pollution and public health damage in the United States: an update Health Aff (Millwood) 39(12) 2071–2079 https://doi.org/10.1377/hlthaff.2020.01247 PMID: 33284703
69. Gorgun E, Dehipawala S, and O'Hara M, et al (2024) Environmental sustainability initiatives in the operating room: a scoping review Ann Surg Open 5(3) e451 https://doi.org/10.1097/AS9.0000000000000451 PMID: 39310357 PMCID: 11415109
70. Lichter KE, Sabbagh A, and Demeulenaere S, et al (2024) Reducing the environmental impact of health care conferences: a study of emissions and practical solutions JCO Glob Oncol 10 e2300209 https://doi.org/10.1200/GO.23.00209 PMID: 38359373 PMCID: 10881111
71. Network Greener Conference Emissions Calculator [https://networkgreener.com]
72. Baniel CC NorCal Procedural (Brachytherapy) Waste Audit Toolkit [https://drive.google.com/drive/u/0/folders/1ER5urTOScl5ims94i3ZP7MjWhA8u_RJw]
73. Lichter KE, Baniel CC, and Anderson J, et al (2022) Environmentally sustainable brachytherapy care Brachytherapy 21(5) 712–717 https://doi.org/10.1016/j.brachy.2022.06.002 PMID: 35794032 PMCID: 9997716
74. Lichter KE, Charbonneau K, and Lewy JR, et al (2024) Quantification of the environmental impact of radiotherapy and associated secondary human health effects: a multi-institutional retrospective analysis and simulation Lancet Oncol 25(6) 790–801 https://doi.org/10.1016/S1470-2045(24)00148-7 PMID: 38821084
75. Bhatia RK, Lichter KE, and Zaorsky NG, et al (2024) Using hypofractionation to decarbonise radiation oncology BMJ 386 e079072 https://doi.org/10.1136/bmj-2023-079072 PMID: 39164042
76. Adshead F, Al-Shahi Salman R, and Aumonier S, et al (2021) A strategy to reduce the carbon footprint of clinical trials Lancet 398(10297) 281–282 https://doi.org/10.1016/S0140-6736(21)01384-2 PMID: 34171294
77. Griffiths J, Fox L, and Williamson PR, et al (2024) Quantifying the carbon footprint of clinical trials: guidance development and case studies BMJ Open 14(1) e075755 https://doi.org/10.1136/bmjopen-2023-075755 PMID: 38267250 PMCID: 10823997
78. Griffiths J, Adshead F, and Al-Shahi Salman R, et al (2024) What is the carbon footprint of academic clinical trials? A study of hotspots in 10 trials BMJ Open 14(10) e088600 https://doi.org/10.1136/bmjopen-2024-088600 PMID: 39414270 PMCID: 11487931
79. Mackillop N, Shah J, and Collins M, et al (2023) Carbon footprint of industry-sponsored late-stage clinical trials BMJ Open 13(8) e072491 https://doi.org/10.1136/bmjopen-2023-072491 PMID: 37604634 PMCID: 10445340
80. LaRoche JK, Alvarenga R, and Collins M, et al (2024) Climate footprint of industry-sponsored clinical research: an analysis of a phase-1 randomised clinical study and discussion of opportunities to reduce its impact BMJ Open 14(1) e077129 https://doi.org/10.1136/bmjopen-2023-077129 PMID: 38216192 PMCID: 10806794
81. Wellcome Concordat for the Environmental Sustainability of Research and Innovation Practice [https://wellcome.org/who-we-are/positions-and-statements/environmental-sustainability-concordat]
82. Sustainable Markets Initiative Heath Systems Task Force [https://www.sustainable-markets.org/taskforces/health-systems-taskforce/]
83. National Institute for Health and Care Research NIHR Carbon Reduction Guidelines 2019 [https://www.nihr.ac.uk/about-us/what-we-do/key-initiatives/climate-health-sustainability/carbon-reduction-guidelines]
84. UKCRC Registered Clinical Trials Units Recommendations for Undertaking Greener Monitoring [http://ukcrc-ctu.org.uk/guidance-for-ctus/]
85. TMRP Greener Trials Group Enabling Lower Carbon Clinical Trials [https://www.methodologyhubs.mrc.ac.uk/about/working-groups/trial-conductwg/tcwg-subgroup-greener-trials/enabling-lower-carbon-clinical-trials-cict-project/]
86. Lynch E, Bredin P, and Weadick CS, et al (2024) Why we should, and how we can, reduce the climate toxicity of cancer care JCO Oncol Pract OP2400680.
87. Myo J, Pooley S, and Brennan F (2021) Oral, in place of intravenous, paracetamol as the new normal for elective cases Anaesthesia 76(8) 1143–1144 https://doi.org/10.1111/anae.15482 PMID: 33858028
88. Eii MN, Walpole S, and Aldridge C (2023) Sustainable practice: prescribing oral over intravenous medications BMJ 383 e075297 https://doi.org/10.1136/bmj-2023-075297 PMID: 37931943
89. Dennis P (2023) Report: more single-use plastic waste in the world than ever before Circular
90. Daughton CG (2014) Eco-directed sustainable prescribing: feasibility for reducing water contamination by drugs Sci Total Environ 493 392–404 https://doi.org/10.1016/j.scitotenv.2014.06.013 PMID: 24956075
91. Cliff BQ, Avancena ALV, and Hirth RA, et al (2021) The impact of choosing wisely interventions on low-value medical services: a systematic review Milbank Q 99(4) 1024–1058 https://doi.org/10.1111/1468-0009.12531 PMID: 34402553 PMCID: 8718584
92. Hilal T and Munoz J (2020) Choosing wisely(R) in hematology: have we made a difference? Curr Hematol Malig Rep 15(4) 241–247 https://doi.org/10.1007/s11899-020-00593-2 PMID: 32533390 PMCID: 7291941
93. Lyu H, Xu T, and Brotman D, et al (2017) Overtreatment in the United States PLoS One 12(9) e0181970 https://doi.org/10.1371/journal.pone.0181970 PMID: 28877170 PMCID: 5587107
94. Brownlee S, Chalkidou K, and Doust J, et al (2017) Evidence for overuse of medical services around the world Lancet 390(10090) 156–168 https://doi.org/10.1016/S0140-6736(16)32585-5 PMID: 28077234 PMCID: 5708862
95. Nagarajah S, Powis ML, and Fazelzad R, et al (2022) Implementation and impact of choosing wisely recommendations in oncology JCO Oncol Pract 18(10) 703–712 https://doi.org/10.1200/OP.22.00130 PMID: 35930757
96. Booth CM, Sengar M, and Goodman A, et al (2023) Common sense oncology: outcomes that matter Lancet Oncol 24(8) 833–835 https://doi.org/10.1016/S1470-2045(23)00319-4 PMID: 37467768
97. Pak LM and Morrow M (2022) Addressing the problem of overtreatment in breast cancer Expert Rev Anticancer Ther 22(5) 535–548 https://doi.org/10.1080/14737140.2022.2064277 PMID: 35588396 PMCID: 9448354
98. Forrest C, O'Donoghue K, and Collins DC, et al (2023) Current irish medicolegal landscape: an unsustainable trajectory BMJ Open Qual 12(3) e002433 https://doi.org/10.1136/bmjoq-2023-002433 PMID: 37607759 PMCID: 10445350
99. Prigerson HG, Bao Y, and Shah MA, et al (2015) Chemotherapy use, performance status, and quality of life at the end of life JAMA Oncol 1(6) 778–784 https://doi.org/10.1001/jamaoncol.2015.2378 PMID: 26203912 PMCID: 4828728
100. Wright AA, Zhang B, and Keating NL, et al (2014) Associations between palliative chemotherapy and adult cancer patients' end of life care and place of death: prospective cohort study BMJ 348 g1219 https://doi.org/10.1136/bmj.g1219 PMID: 24594868 PMCID: 3942564
101. Wallington M, Saxon EB, and Bomb M, et al (2016) 30-day mortality after systemic anticancer treatment for breast and lung cancer in England: a population-based, observational study Lancet Oncol 17(9) 1203–1216 https://doi.org/10.1016/S1470-2045(16)30383-7 PMID: 27599138 PMCID: 5027226
102. Mallett V, Linehan A, and Burke O, et al (2021) A multicenter retrospective review of systemic anti-cancer treatment and palliative care provided to solid tumor oncology patients in the 12 weeks preceding death in Ireland Am J Hosp Palliat Care 38(12) 1404–1408 https://doi.org/10.1177/1049909120985234 PMID: 33438436
103. Jewitt N, Rapoport A, and Gupta A, et al (2023) The effect of specialized palliative care on end-of-life care intensity in AYAs with cancer J Pain Symptom Manage 65(3) 222–232 https://doi.org/10.1016/j.jpainsymman.2022.11.013
104. Temel JS, Greer JA, and Muzikansky A, et al (2010) Early palliative care for patients with metastatic non-small-cell lung cancer N Engl J Med 363(8) 733–742 https://doi.org/10.1056/NEJMoa1000678 PMID: 20818875
105. Seow H, Barbera LC, and McGrail K, et al (2022) Effect of early palliative care on end-of-life health care costs: a population-based, propensity score-matched cohort study JCO Oncol Pract 18(1) e183–e192 https://doi.org/10.1200/OP.21.00299
106. Davis MP, Vanenkevort EA, and Elder A, et al (2023) The financial impact of palliative care and aggressive cancer care on end-of-life health care costs Am J Hosp Palliat Care 40(1) 52–60 https://doi.org/10.1177/10499091221098062
107. Cherny NI, Dafni U, and Bogaerts J, et al (2017) ESMO-magnitude of clinical benefit scale version 1.1 Ann Oncol. 2017;28(10):2340-66. https://doi.org/10.1093/annonc/mdx310 PMID: 28945867
108. ASCO Value Framework Net Health Benefit Worksheet: Advanced Disease Setting [https://society.asco.org/sites/new-www.asco.org/files/content-files/practice-and-guidelines/documents/2020-NHB-advanced-disease-setting-worksheet.pdf]
109. Hess LM, Cui ZL, and Li XI, et al (2018) Drug wastage and costs to the healthcare system in the care of patients with non-small cell lung cancer in the United States J Med Econ 21(8) 755–761 https://doi.org/10.1080/13696998.2018.1467918 PMID: 29673274
110. Bach PB, Conti RM, and Muller RJ, et al (2016) Overspending driven by oversized single dose vials of cancer drugs BMJ 352 i788 https://doi.org/10.1136/bmj.i788 PMID: 26932932 PMCID: 6894487
111. Leung CYW, Cheung MC, and Charbonneau LF, et al (2017) Financial impact of cancer drug wastage and potential cost savings from mitigation strategies J Oncol Pract 13(7) e646–e652 https://doi.org/10.1200/JOP.2017.022905 PMID: 28605255
112. Staskon FC, Kirkham HS, and Pfeifer A, et al (2019) Estimated cost and savings in a patient management program for oral oncology medications: impact of a split-fill component J Oncol Pract 15(10) e856–e862 https://doi.org/10.1200/JOP.19.00069 PMID: 31465250 PMCID: 6790878
113. Khandelwal N, Duncan I, and Ahmed T, et al (2011) Impact of clinical oral chemotherapy program on wastage and hospitalizations J Oncol Pract 7(3 Suppl) e25s-e29s https://doi.org/10.1200/JOP.2011.000301 PMID: 21886508 PMCID: 3092454
114. Monga V, Meyer C, and Vakiner B, et al (2019) Financial impact of oral chemotherapy wastage on society and the patient J Oncol Pharm Pract 25(4) 824–830 https://doi.org/10.1177/1078155218762596
115. Durr P, Schlichtig K, and Krebs S, et al (2022) [Economic aspects in the care of patients with new oral anticancer drugs: findings from the AMBORA trial] Z Evid Fortbild Qual Gesundhwes 169 84–93 PMID: 35249863
116. Bekker CL, Melis EJ, and Egberts ACG, et al (2019) Quantity and economic value of unused oral anti-cancer and biological disease-modifying anti-rheumatic drugs among outpatient pharmacy patients who discontinue therapy Res Social Adm Pharm 15(1) 100–105 https://doi.org/10.1016/j.sapharm.2018.03.064
117. Goff Z, Abbotsford J, and Yeoh DK, et al (2022) The impact of a multifaceted tertiary pediatric hospital's antimicrobial stewardship service Pediatr Infect Dis J 41(12) 959–966 https://doi.org/10.1097/INF.0000000000003704 PMID: 36102734
118. Gillies MB, Burgner DP, and Ivancic L, et al (2022) Changes in antibiotic prescribing following COVID-19 restrictions: lessons for post-pandemic antibiotic stewardship Br J Clin Pharmacol 88(3) 1143–1151 https://doi.org/10.1111/bcp.15000
119. Chaput G and Bhanabhai H (2023) Deprescribing: a prime opportunity to optimize care of cancer patients Curr Oncol 30(11) 9701–9709 https://doi.org/10.3390/curroncol30110704 PMID: 37999124 PMCID: 10670366
120. Williams PA, Zaidi SK, and Sengupta R (2024) AACR cancer progress report 2024: inspiring science-fueling progress-revolutionizing care Clin Cancer Res 30(19) 4296–4298 https://doi.org/10.1158/1078-0432.CCR-24-2820 PMID: 39292173
121. Crippa M, Solazzo E, and Guizzardi D, et al (2021) Food systems are responsible for a third of global anthropogenic GHG emissions Nat Food 2(3) 198–209 https://doi.org/10.1038/s43016-021-00225-9 PMID: 37117443
122. Gonzalez N, Marques M, and Nadal M, et al (2020) Meat consumption: which are the current global risks? A review of recent (2010–2020) evidences Food Res Int 137 109341 https://doi.org/10.1016/j.foodres.2020.109341
123. Semba RD, Neu P, and Berg P, et al (2024) The origins and growth of the meatless monday movement Front Nutr 11 1283239 https://doi.org/10.3389/fnut.2024.1283239 PMID: 38549754 PMCID: 10976850
124. Otto IM, Donges JF, and Cremades R, et al (2020) Social tipping dynamics for stabilizing Earth's climate by 2050 Proc Natl Acad Sci U S A 117(5) 2354–2365 https://doi.org/10.1073/pnas.1900577117 PMID: 31964839 PMCID: 7007533
125. Luo OD, Razvi Y, and Kaur G, et al (2023) A qualitative study of what motivates and enables climate-engaged physicians in Canada to engage in health-care sustainability, advocacy, and action Lancet Planet Health 7(2) e164-e171 https://doi.org/10.1016/S2542-5196(22)00311-4 PMID: 36754472
126. Han J, Zhang M, and Liu J, et al (2024) The medusa effect: a registered replication report of Will, Merritt, Jenkins and Kingstone (2021) R Soc Open Sci 11(1) 231802ss https://doi.org/10.1098/rsos.231802
127. Montoro-Ramirez EM, Parra-Anguita L, and Alvarez-Nieto C, et al (2024) Climate change effects in older people's health: a scoping review J Adv Nurs. https://doi.org/10.1111/jan.16270 PMID: 38895960
128. Espinel Z, Nogueira LM, and Gay HA, et al (2022) Climate-driven Atlantic hurricanes create complex challenges for cancer care Lancet Oncol 23(12) 1497–1498 https://doi.org/10.1016/S1470-2045(22)00635-0 PMID: 36272419
129. Spanos S, Dammery G, and Pagano L, et al (2024) Learning health systems on the front lines to strengthen care against future pandemics and climate change: a rapid review BMC Health Serv Res 24(1) 829 https://doi.org/10.1186/s12913-024-11295-3 PMID: 39039551 PMCID: 11265124
130. Chen L, Brun P, and Buri P, et al (2025) Global increase in the occurrence and impact of multiyear droughts Science 387(6731) 278–284 https://doi.org/10.1126/science.ado4245 PMID: 39818908
131. Simeone CE, Hammond JC, and Archfield SA, et al (2024) Declining reservoir reliability and increasing reservoir vulnerability: long-term observations reveal longer and more severe periods of low reservoir storage for major United States reservoirs Geophys Res Letts 51 e2024GL.109476 https://doi.org/10.1029/2024GL109476
132. Piecuch CG and Beal LM (2023) Robust weakening of the gulf stream during the past four decades observed in the Florida straits Geophys Res Lett 50 e2023GL105170 https://doi.org/10.1029/2023GL105170
133. Bryden H, Beunk J, and Drijfhout S, et al (2024) Comparing observed and modelled components of the Atlantic Meridional Overturning Circulation at 26°â€‰N Ocean Sci 20(2) 589–599 https://doi.org/10.5194/os-20-589-2024
134. Gou R, Lohmann G, and Wu L (2024) Atlantic meridional overturning circulation decline: tipping small scales under global warming Phys Rev Lett 133(3) 034201 https://doi.org/10.1103/PhysRevLett.133.034201 PMID: 39094135
135. Greene CH, Pershing AJ, and Cronin TM, et al (2008) Arctic climatechange and its impacts on the ecology of the North Atlantic Ecology 89(11 Suppl) S24–S38 https://doi.org/10.1890/07-0550.1 PMID: 19097482
136. World Meteorlogical Organization. WMO Report Documents Spiralling Weather and Climate Impacts 2025 [https://wmo.int/news/media-centre/wmo-report-documents-spiralling-weather-and-climate-impacts]
137. Ewbank C, Stewart B, and Bruns B, et al (2021) The development of a surgical care and climate change matrix: a tool to assist with prioritization and implementation strategies Ann Surg 273(2) e50-e51 https://doi.org/10.1097/SLA.0000000000003980
138. Robb HD and Pegna V (2023) The intercollegiate green theatre checklist Bull R Coll Surg Engl 105(2) 64–67. https://doi.org/10.1308/rcsbull.2023.25
139. Centre for Sustainable Healthcare Surgical Care Sustainability Network [http://networks.sustainablehealthcare.org.uk/surgical-care-sustainability-network/about]
140. Dupraz C, Ducrot C, and Allignet B, et al (2024) The carbon footprint of external beam radiotherapy and its impact in health technology assessment Clin Transl Radiat Oncol 48 100834 PMID: 39211397 PMCID: 11359761
141. Piffoux M, Delpon G, and Ducrot C, et al (2023) Insights on the carbon footprint of radiotherapy in France Cancer Radiother 27(6–7) 487–490 https://doi.org/10.1016/j.canrad.2023.07.009 PMID: 37558609
142. Ali D and Piffoux M (2024) Methodological guide for assessing the carbon footprint of external beam radiotherapy: a single-center study with quantified mitigation strategies Clin Transl Radiat Oncol 46 100768 PMID: 38633470 PMCID: 11021844
143. ESMO Climate Change Taskforce ESMO Climate Change Taskforce 2023 [https://www.esmo.org/about-esmo/organisational-structure/esmo-task-forces/climate-change-task-force]
144. National Institute of Environmental Health Sciences Climate Change and Human Health Literature Portal [https://tools.niehs.nih.gov/cchhl/]
145. Health Care Without Harm Health Care Without Harm Europe [https://europe.noharm.org]
146. Health Care Without Harm Climate Impact Checkup Online Course [https://training.noharm.org/?lang=en&lang=en]
147. Joint Commission International Joint Commission International [https://www.jointcommissioninternational.org]
148. International Hospital Federation Geneva Sustainability Centre Toolbox [https://ihf-fih.org/what-we-do/geneva-sustainability-centre/sustainability-toolbox/]
149. Global Green and Healthy Hospitals Acting Together for Environmental Health [https://greenhospitals.org]
150. Irish College of General Practitioners Glas Toolkit 2023 [https://www.irishcollegeofgps.ie/Portals/0/Explore%20the%20College/Sustainability%20&%20Planetary%20Health/ETC_Sustainability_Glas_Toolkit_v7.pdf]
151. Royal College of Physicians London Green Physician Toolkit 2024 [https://www.rcp.ac.uk/media/tmqazjjl/green-physician-toolkit-july-2024.pdf].
152. Royal College of General Practitioners Green Impact for Health Toolkit [https://toolkit.sos-uk.org/greenimpact/giforhealth/login]
153. Canadian Association of Physicians for the Environment Climate Change Toolkit for Health Professionals 2019 [https://chasecanada.org/wp-content/uploads/2021/01/Climate-Change-Toolkit-for-Health-Professionals-Full-Toolkit.pdf]
154. Irish Doctors for the Environment A Guide to Being a Green Prescriber: Inhalers 2022 [https://ide.ie/wp-content/uploads/2022/11/Inhalers-Toolkit-Evidence-Document.pdf]
155. Rockall AG, Allen B, and Brown MJ, et al (2025) Sustainability in radiology: position paper and call to action from ACR, AOSR, ASR, CAR, CIR, ESR, ESRNM, ISR, IS3R, RANZCR, and RSNA Eur Radiol 1–10.
156. Richards DA, Bellon F, and Goñi-Fuste B, et al (2024) A behaviour change strategy to reduce greenhouse gas emissions from international scientific conferences and meetings Nat Clim Change 3 95.
157. Herziger A and Hurst KF (2025) The role of cross- and interdisciplinary climate research centres Nat Clim Change 15 228–230 https://doi.org/10.1038/s41558-025-02249-6
