The world has had a rude awakening when it comes to the vulnerability of its health systems. Infectious diseases such as COVID-19 and the impacts of climate change have strained health systems across the globe and demonstrated how unprepared the world is to respond to these growing threats. Climate disasters are increasingly and painfully commonplace. From 2018 to 2022, the United States alone experienced 18 weather and climate disasters that cost at least $1 billion each.1
In the first ten months of 2023, there were 25 such events.2
Climate impacts are also expected to worsen globally: from 2030 to 2050, an additional 250,000 global deaths related to climate change are expected per year.3
And unfortunately, COVID-19 wasn’t the last pandemic.4

Just as these two threats are, in many ways, intertwined (for example, a warming planet is exacerbating zoonotic threats), so are their solutions. Health system climate adaptation and pandemic preparedness and response can help health systems respond to both threats. Yet while the financing needs for both climate adaptation and pandemic preparedness have been well documented, there is limited understanding of the overlap between these agendas.

New McKinsey research highlights that overlap: we have identified $7 billion to $25 billion in high-impact investments that could promote resilience against both climatic and infectious threats. About 25 percent of this investment can contribute directly to strengthening primary healthcare more broadly. In the context of global healthcare spending (which rose to $9 trillion in 2020),5
this relatively small investment could pay significant dividends in advancing pressing current and future health goals.

Below, we explore both threats in more detail and consider specific investment activities in three systems—pandemic preparedness and response, health system climate adaptation, and primary healthcare (see sidebar, “Methodology”). We then highlight the four areas among these three systems where governments and philanthropic organizations can focus their efforts concurrently to have a substantial impact on human health.

More than three billion people live in environments that are highly vulnerable to climate change.6
They will potentially experience more risks to their health from climate change. These threats could come directly, such as through extreme heat, and indirectly, such as through disrupted routine health services during extreme weather events. The increasing frequency and severity of infectious outbreaks also looms on the horizon, with estimates suggesting an event resembling the COVID-19 pandemic has an annual probability of 2 to 3 percent; that is, it can be expected to occur once every 33 to 50 years.7
With the climate crisis possibly leading to more outbreaks and more noncommunicable diseases, it also threatens to increase the strain on health systems.8
The climate impacts on health are receiving more cross-governmental attention, and health is increasingly an agenda item at high-level climate meetings.9

Similarly, recent infectious-disease outbreaks, including COVID-19 and Mpox,10
have drawn global attention to the pressing need for greater investment in pandemic preparedness. We have previously estimated that an annual expenditure of about $35 billion per year over the next ten years could substantially reduce the likelihood of future pandemics11
; others have called for investment of similar magnitude.12
In addition to domestic, bilateral, and multilateral donor commitments, the creation of the Pandemic Fund in November 2022 demonstrates a shared global commitment to greater pandemic preparedness.13

Addressing the dangers of climate change and infectious diseases requires resilient primary-healthcare systems that can respond rapidly and effectively. Yet financial resources for health system investments—and public budgets more broadly—are finite. Given this context, stakeholders will need to make difficult decisions regarding resource allocation. Allocating funding to areas that create synergies across all three goals will provide a source of value creation moving forward.

Attaining the scale of investment necessary to achieve these goals may seem daunting, but a thoughtful approach that targets and monitors synergies can help. The total estimated financing gap to solely address climate adaptation is $26 billion to $56 billion, while the comparable figure for pandemic preparedness ranges from $11 billion to $39 billion, with $7 billion to $25 billion in overlap between the two areas (exhibit). In our analysis, about 25 percent of pandemic preparedness and climate adaptation spend (represented by sections 1, 2, and 4 in the exhibit) also contributes directly to primary-healthcare systems. This synergy results in meaningful public savings. Indeed, for every $5.00 of additional funding invested in climate adaptation or pandemic preparedness, there is the potential to deliver between $2.50 and $3.80 in shared value across two or more objectives.

Below, we explore specific opportunities for investment in each of the areas of overlap.

The collaborative benefits between preparing for pandemics and stronger primary-healthcare infrastructure can include better coordination and planning mechanisms. For example, investments in integrated data systems and national public-health institutes can support nationally coordinated pandemic responses by better connecting national, district, and local service delivery units and providing transparency over needs and resources (such as workforce, consumables, and supplies). Another example includes initiatives such as establishing antiviral, antibody, and vaccine development platforms; this type of synergy is illustrated by the growth of vaccine portfolios for alliances such as Gavi, whose portfolio includes 19 infectious diseases (up from four in 2000), with recent additions of the malaria and oral cholera vaccines.14

Strengthening primary healthcare requires, at a minimum, building climate-resilient capabilities in the delivery of primary-care services. This includes, for instance, increasing the system’s capacity to handle a surge in demand or fostering a more agile supply chain that can handle climate-related challenges. Climate-resilient infrastructure and technologies can aid this effort in two ways. The first is by adapting existing processes—for example, increasing reach, capacity, or both through current community partnerships. The second is by promoting new technologies and products—for example, digital care and novel vaccines, such as those for malaria or Lassa fever. At the same time, climate-resilient capabilities can also enhance the sustainability of health operations by, for instance, ensuring cross-capacity training for staff in the event of a surge.

Beyond service delivery, simultaneously advancing both climate resilience and primary healthcare will require investments to strengthen health information management systems. These systems should include the ongoing assessment of health vulnerability, capacity, and adaptation (for example, health system capacity), integrated risk monitoring (for example, flood risks) and early warning (for example, identification of new mosquito strains in certain environments), and health and climate research, including capacity building and connecting research to policy.

Last, both goals could be addressed by strengthening climate health capacity in leadership and governance; building the health workforce through training and education, organizational capacity development, and communications; and raising awareness. This could ensure that primary healthcare adequately recognizes climate-health-related challenges (for example, new illnesses) while breaking silos of climate health adaptation activities beyond traditional infrastructure investments.

To spur these efforts, both the World Bank and the World Health Organization (WHO) have committed to supporting climate-resilient primary healthcare. This includes providing technical assistance on climate change and health vulnerability and adaptation assessments in addition to enabling initiatives such as the creation of a high-level steering committee in Dominica led by the prime minister and the minister of health and environment.15
Stakeholders can direct investments to support the strategic planning of health programs for climate-sensitive diseases, as well as strengthening existing public-health programs with updated standard operating procedures that can effectively respond to climate risks while delivering routine interventions.

To better prepare for climate-change-related health emergencies, health systems will need to focus on strengthening disease detection, disaster preparedness, and infrastructure against climate risks. This may entail enhancing physical infrastructure to protect against flooding, mapping and identifying unknown zoonotic viral threats to reduce their risks, and planning for potential increases in healthcare demand—for example, an increase in emergency room visits following a heat wave. These goals can be further advanced by designing strategies to identify and address known diseases exacerbated by climate change. There is additional overlap among these activities through regular surveillance activities, which includes systems for notifiable diseases, integrated disease surveillance and response systems, and pathogen surveillance, including genomic sequencing. To more definitively advance climate adaptation and pandemic preparedness in parallel, health systems will need to stress test their disaster preparedness systems and make the appropriate improvements to emergency operations, conduct regular simulations of health emergencies, and complete other cross-sectoral activities such as health emergency preparedness and response workforce capacity building and training.

Our analysis has identified four areas in which stakeholder investment can further all three goals simultaneously:

Access to countermeasures. Building the global stockpile of vaccines, treatments, and diagnostics can ensure adequate, timely, and equitable global responses to outbreaks. This includes “hot spots” such as parts of Africa across the Sahel, Central Africa, and East Africa, where the rate of mortality driven by climate hazards could be 15 times higher than in the least-vulnerable countries.16
These stockpiles may be physical or virtual, or, at a minimum, include access agreements to countermeasures. For example, UNICEF, WHO, the International Federation of Red Cross and Red Crescent Societies, Médecins Sans Frontières/Doctors Without Borders, and Gavi established a global Ebola vaccine stockpile to ensure timely access to vaccines for populations at risk during outbreaks.17
This also includes community-engagement and risk-communication activities, which, where relevant, can minimize health vulnerabilities of communities most at risk.

Antimicrobial resistance. Heightened demand for treatment during the pandemic led to increased overuse and misuse of antibiotics in healthcare settings, which in turn exacerbated the threat of antimicrobial resistance (AMR).18
Concurrently, the consequences of climate change, such as rising water temperatures and drivers of zoonotic disease, are also directly and indirectly affecting AMR. Climate change (that is, warming) is associated with increased transmission of new and reemerging pathogens like carbapenem-resistant Pseudomonas aeruginosa.19

The absolute effect of these climate-related factors on AMR has yet to be quantified.20
To aid AMR efforts, WHO published a global research agenda in June 2023 outlining the most urgent research priorities to combat AMR, including 40 topics to be addressed by 2030.21
Our analysis found that there are prevention activities related to AMR that could create value in multiple areas concurrently. With smart investing across all three goals, these activities could help contain AMR by improving infection prevention and control, waste disposal, and awareness. They could also extend antimicrobial effectiveness by, for instance, strengthening quality, trade, distribution, and sales.

Communication and community engagement. Achieving more-resilient pandemic preparedness and response, climate adaptation, and primary-healthcare systems cannot be done without comprehensive communication activities. These activities have inherent synergies that involve risk communication systems, public coordination, communication engagement with affected communities, and dynamic listening and rumor management. For example, WHO recently published an evaluation of one of its community engagement research initiatives in the Western Pacific region, highlighting the importance of relational leadership, community engagement, and cultures of experimentation anchored in safety and trust.22
As climate and pandemic risks continue to occur, potentially at increased frequency, health systems that prioritize establishing reliable and inclusive communication and community engagement (for example, mobilizing awareness, including representation from marginalized groups, and growing peer networks) will be better positioned to cultivate and sustain trust while ensuring equitable and optimal outcomes for all.23

Specialized surveillance programs. Finally, specialized surveillance programs (for instance, sero-surveillance, genomic sequencing, wastewater surveillance, and vaccine effectiveness studies) support the delivery of all three goals concurrently. For example, for years, communities have surveilled wastewater as a way of rapidly responding to and eradicating infections, as was the case with polio.24
These surveillance capabilities are a cornerstone of increasing resilience in our health systems, especially as the world strives to identify climate and pandemic risks as early as possible. By using specialized surveillance programs, health systems can sufficiently prepare for these risks and respond with more accuracy and efficiency. Africa CDC, WHO, and the Robert Koch Institute are prioritizing this effort, as demonstrated by the launch of the Health Security Partnership in July 2023. The partnership specifically aims to strengthen capabilities in biosecurity, integrated disease surveillance, event-based surveillance, genomic surveillance, and epidemic intelligence.25

Today’s most pressing health needs and challenges call for targeted funding in the above four areas. Governments, philanthropies, and other stakeholders can optimize their investments to improve healthcare while also maximizing the impact on public health and well-being. Donors, climate stakeholders, and health organizations could mobilize at upcoming forums to discuss insights and align on future priorities. Key stakeholders could also consider establishing a shared investment framework for the future that prioritizes and ensures synergy among their investments—or, at least, does not create redundancy and waste. Governments, donors, and health organizations can maximize the impact of overlapping investment if they each commit to the same set of priorities:

This analysis provides a starting point for discussion and action; however, refining the definitions—particularly the activities underpinning each overlap—and synthesizing and analyzing a more complete data set could lead to better outcomes and provide a mor-precise sizing of the opportunity available. Decision makers could then more accurately prioritize funding activities that achieve multiple health system goals concurrently and build the resilience of health systems globally.

Governments, philanthropies, and other stakeholders play a pivotal role in advancing high-impact investments and, broadly, shaping synergies among climate adaptation, pandemic preparedness, and primary healthcare going forward. Maximizing the resilience of national health systems will require cross-sector collaboration, with decision making informed by rigorous prospective analyses. While key stakeholders such as WHO, the World Bank, and the OECD are recognizing the importance of health system resilience,27
more can be done to understand the areas of synergies. These vital efforts will not only mobilize essential investments for building health system resilience and mitigating risks from the impacts of climate change and infectious diseases but also drive the achievement of a range of national goals aimed at addressing human health on a global scale.