https://orcid.org/0000-0003-2270-2313
Figures
Abstract
Healthcare faces a dual mandate: protect people from intensifying climate hazards while cutting its own footprint. Globally, healthcare produces 4%–5% of greenhouse gas emissions, largely from supply chains. England’s National Health Service has paired targets with tools—procurement standards, clinical guidance, estates upgrades, and transparent measurement—to deliver early wins. Japan now stands at an implementation frontier: a November 2025 Health and Global Policy Institute survey of 152 organizations shows high awareness but limited “how‑to” knowledge and little action. This Opinion proposes a sequenced roadmap—Education, Measurement, Incentives—aligned with CMIP’s regularly updated climate data. Priorities are climate‑health content in continuing education, a minimum viable measurement set aligned with standards, and procurement, finance, and recognition to deliver reductions and resilience within 12–36 months. Aligning operations to CMIP’s cadence can position Japan’s health sector as a credible contributor to national climate goals and provide a scalable template for others.
Citation: Kubota K (2025) From awareness to action: A three‑lever, CMIP‑aligned roadmap to decarbonize and climate‑proof Japan’s healthcare sector. PLOS Clim 4(12): e0000785. https://doi.org/10.1371/journal.pclm.0000785
Editor: Jamie Males, PLOS Climate, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
Published: December 11, 2025
Copyright: © 2025 Kazumi Kubota. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: The authors received no specific funding for this work.
Competing interests: The authors have declared that no competing interests exist.
Introduction
The dual mandate and a changing data landscape
Health systems must protect people from extreme heat, floods, storms, supply chain shocks, and shifting infectious risks while reducing their own emissions. Healthcare produces roughly 4%–5% of global greenhouse gases, with upstream supply chains dominating [1]. Systems advancing fastest, notably England’s NHS, pair explicit targets with practical instruments—procurement standards, clinical guidance, estates upgrades, and transparent reporting—to deliver verifiable wins without compromising care [2]. Meanwhile, climate data infrastructure is evolving. The World Climate Research Programme’s CMIP is moving toward regular updates—annual extensions of historical forcings and five-year projections aligned to the UNFCCC Global Stocktake—via the CMIP7 Assessment Fast Track, bringing semi-operational data closer to decision-makers [3,4]. These shifts enable health services to turn modeling advances into routine triggers for risk management, capital planning, and preparedness, consistent with IPCC assessments of escalating risks [5].
Japan’s implementation frontier: what the HGPI survey reveals
Japan’s healthcare sector shows high awareness, uneven “how‑to” knowledge, and scarce implementation. A November 2025 Health and Global Policy Institute (HGPI) survey of 152 organizations—academic societies, professional associations, and industry bodies—found near‑universal recognition that climate change threatens health but much lower familiarity with actionable measures [6]. About nine in ten academic societies reported neither providing climate‑health continuing education nor formulating environmental measures; industry bodies showed more activity but far from scale. Many support stronger policy and investment yet remain unsure of practical pathways. The barrier is not denial but the absence of a concrete, low‑burden playbook.
A sequenced roadmap: Education → Measurement → Incentives
This Opinion proposes a three‑lever sequence designed for Japan’s institutions and informed by international experience. The levers reinforce each other: education builds capacity and legitimacy; measurement provides a shared evidence base; incentives align resources and recognition.
Education—making climate competency the default
Foundational climate competency should be integrated into continuing professional development for clinicians, pharmacists, nurses, administrators, and boards. Early modules emphasize clinical relevance: recognizing heat illness and climate‑sensitive infections, preparing for extreme weather and cascading failures, choosing low‑carbon anesthetic and perioperative pathways where appropriate, and understanding governance duties for climate risk [7]. Because respondents are organizational leaders, top‑down endorsement is feasible: academic societies can authorize starter curricula, embed content in examinations and accreditation, and normalize low‑carbon meetings through hybrid formats. Micro‑credential modules of 15–30 minutes fit busy schedules.
Measurement—building the minimum viable system
Efforts should start with what facilities already track and what global accounting requires, while keeping scope manageable in year one. A minimum viable set combines routine activity data with nationally appropriate emission factors and phases in deeper supply‑chain detail over two to three years, aligned with the Greenhouse Gas Protocol and ISO practice [8]. Because clinical hot spots—especially inhalational anesthetics and nitrous oxide, energy‑intensive imaging, and single‑use consumables—disproportionately shape footprints, facilities should prioritize visibility here to enable quick wins and clinician engagement, supported by evidence on anesthetic agents’ climate impacts [9].
Incentives—aligning money, procurement, and recognition
Implementation accelerates when procurement and finance align with measurement. Japan can pilot green procurement in high‑impact categories by requesting environmental product declarations or phased climate roadmaps and signaling preferred options where clinically equivalent—such as avoiding desflurane and addressing nitrous oxide leakage—drawing on the NHS Net Zero Supplier Roadmap [2,10]. Finance can lower barriers through energy‑efficiency and electrification subsidies, environmentally rated loans, and power purchase agreements for renewable electricity. A light‑touch national recognition program tied to standardized reporting can harness peer effects without heavy compliance costs.
A CMIP‑aligned research‑to‑operations pipeline for health
To close the gap between climate science and operations, healthcare can align risk management and planning cycles to the CMIP cadence [3,4]. Annual extensions of historical forcings, downscaled through national and regional systems, can feed operational triggers such as heat‑health early warnings, thresholds that activate continuity plans, and seasonally adjusted surveillance for climate‑sensitive infections. Five‑year updates aligned with the Global Stocktake can inform capital programs for electrified heat, on‑site storage, and microgrids, and reset assumptions about compound events that disrupt care and supply chains. This pipeline is illustrated in Fig 1.
Annual extensions of historical forcings and five‑year scenario updates from the CMIP7 Assessment Fast Track flow through national downscaling (e.g., Japan Meteorological Agency/AMeDAS and CORDEX‑East Asia) to produce health‑relevant indicators (e.g., wet‑bulb globe temperature exceedance days, intense precipitation thresholds, typhoon track probabilities). Indicators feed an annual operations layer (heat‑health protocols, infection surveillance adjustments, continuity plans) and a five‑year capital planning layer (electrification, storage, microgrids).
Operationalizing measurement and incentives
A year‑one minimum viable set can include ten items: electricity with utility emission factors; combustion fuels by volume; anesthetics by agent and volume converted to CO2e using agent‑specific GWP100 values; nitrous oxide use and estimated leakage; imaging energy intensity; waste by treatment pathway; business travel kilometers by mode; high‑impact purchasing spend estimated with environmentally extended input–output factors; renewable electricity share; and resilience asset capacity and protocols [8]. This concise set enables first‑year learning and comparability; open data dictionaries and calculators can reduce effort. Procurement can unlock upstream decarbonization via a green formulary for anesthetic practice, nitrous oxide abatement, and phased supplier disclosures [10]. Early reductions are available: phasing out desflurane can cut facility emissions by about one percent where alternatives exist [9], while hospital energy upgrades commonly yield 10%–20% electricity savings within a few years. Governance and resilience design should integrate climate risk into routine quality and safety and prioritize electrification, high‑efficiency heat pumps, renewables, storage, and demand response, consistent with WHO guidance [7].
Measuring success
Progress should be tracked annually across three categories of indicators. Process indicators include the share of societies providing climate education, the percentage of facilities submitting the measurement set, and adoption of green procurement. Emissions indicators include absolute and intensity‑based reductions in CO2e from anesthetic gases, energy per square meter, and renewable electricity share. Resilience indicators include existence and activation of heat‑health protocols, completion of climate risk assessments, and documented backup capabilities. The annual cadence aligns with CMIP and budgeting cycles; five‑year planning aligns with scenario updates and capital programs [3].
Conclusion
Japan’s health sector can move from intent to impact now. Sequencing Education, Measurement, and Incentives—and syncing operations with CMIP’s updated climate data—enables quick, verifiable cuts and resilience gains within 12–36 months. These practical steps protect patients, lower costs and risk, and provide a scalable template for other systems.
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