A Policy Perspective on Climate Change, Health, and Health Systems

Submitted by Patricio V. Marquez on Mon, 11/14/2022 - 01:48 PM

A Policy Perspective on Climate Change, Health, and Health Systems

Climate change and health

                         Patricio V Marquez

Back in 2015, in his powerful Encyclical Letter “Laudato Si” or “Praise Be to You, Pope Francis made a powerful statement, unifying both the spiritual and scientific dimensions of life, on one of humanity’s greatest challenges in the 21st Century: environmental destruction and climate change.

As representatives from government, businesses, and civil society meet in Sharm El-Sheikh, Egypt, for the 27th Conference of the Parties (COP27), November 6-18, 2022, to discuss the inescapable urgency of implementing climate pledges and delivering much more climate finance, it is an opportune time to pause and understand how this global challenge is impacting human health and what can be done to mitigate and adapt to its impact and build more resilient societies.

Why Does This Matter?   

Pope Francis’ Encyclical provides a simple and clear explanation to help us understand why environmental destruction and climate change matter: Due to an ill-considered exploitation of nature, humanity runs the risk of destroying it and becoming in turn a victim of this degradation.” 

Beyond the headlines, COP27 should serve as a timely reminder that the use of fossil fuels and human activity globally are destroying, sometimes irreversibly, “mother earth”, our common home.  The impact is visible everywhere in the form of contaminated air, polluted rivers and oceans, widespread deforestation and soil erosion, and deadly hurricanes and storms that wash away miles of coastline, leave buildings crumbling, and cause devastating floods in their wake.  By destroying the environment through our lifestyle choices and actions, we are also contributing to climate change and its negative impact on life-sustaining cycles. Hence, we are contributing to undermine human life itself, and more ominously, to aggravate the plight of the poor and the vulnerable, who face a daily struggle to survive.

Responding to Climate Change and its Impacts

The 2022 World Bank Group report “Climate and Development: An Agenda for Action, argues that climate change, poverty, and inequality are defining challenges of our time—and it is crucial that we tackle them together, acknowledging the interconnections between people, planet, and the economy.  This alignment is needed to sustain past developments gains and secure improvements in living standards across countries. 

To this end, the report offers three insights for action:

  • First, as climate change poses a major threat to long-term development objectives, especially poverty reduction, appropriate adaptation policies are needed to help countries reduce impacts in the short term. But successful development requires rapid reductions in global greenhouse gas (GHG)[i] emissions, which requires first and foremost accelerated mitigation action in high-income countries and other large emitters.
  • Second, climate objectives can be achieved without compromising development, but only if key conditions are met, including well-designed climate actions, strong participation of the private sector, adequate international support, and appropriate complementary measures to manage unavoidable trade-offs, protect the poor, and facilitate a just transition.   
  • Third, success requires challenging policy reforms, reallocation of scarce public resources, increased mobilization of private capital, and increased financial support from the international community.  Resilient and low-carbon pathways can deliver net economic gains, if additional annual investment needs can be met. The transition also requires managing political economy obstacles; strengthening institutions; accelerating diffusion of new technologies; and managing equitable distribution of benefits among the population. To be successful, all countries will require carefully designed policies and scaled-up financial support from richer economies. As low-income countries face higher investment needs, they need access to sustained levels of concessional resources, including grants.

Structuring the Response

As highlighted in the above-mentioned 2022 World Bank Group report, climate change, as a global emergency that goes beyond national borders, requires international cooperation and coordinated solutions at all levels. By September 2022, 136 countries covering 83% of global carbon emissions had set net zero emissions targets by 2050.  The direct and indirect policy responses to address climate change are focused on the drivers or pressures that trigger climate change (i.e., increase in production and demand for goods, services, and transportation and population growth) and documenting the extent and impacts (i.e., how environmental change specifically impacts humans, e.g., in the increase in hazards and exposures). More specifically, in the climate change policy sphere, response is defined as mitigation and adaptation.


To tackle climate change and its negative impacts, world leaders at the 2015 UN Climate Change Conference (COP21) in Paris adopted an historic agreement that set long-term goals to guide all nations:

  • Substantially reduce global greenhouse gas (GHG) emissions to limit the global temperature increase in this Century to 2 degrees Celsius while pursuing efforts to limit the increase even further to 1.5 degrees.
  • Review countries’ commitments every five years. 
  • Provide financing to developing countries to mitigate climate change, strengthen resilience, and enhance capacity to adapt to climate impacts.

A further global target is “a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century”, to ensure net-zero global GHG emissions or achieve worldwide “carbon neutrality” by 2050.  Anthropogenic emissions are polluting emissions that are released during human activities.   For the most part, these are related to the creation of energy to drive our transportation, industries, businesses, waste management systems, and homes.  Carbon dioxide (C02) removal from the atmosphere by “sinks,” (e.g., through the uptake of carbon and storage in forests, vegetation, and soils) occur from management of lands in their current use or as lands are converted to other uses.  Most of the CO2--90%--is emitted by burning fossil fuels; only 10% is emitted as a consequence of land use changes including deforestation.  Currently, on average, 55% of anthropogenic CO2 emissions are rapidly removed from the atmosphere by natural sinks in the ocean and land biosphere, while 45% accumulate in the atmosphere. About 25% of emitted CO2 remains for over 1,000 years. 

Overall, reaching net zero emissions means removing an equal amount of CO2 from the atmosphere as we release into it.  To this end, as reported in a World Economic Forum post, three main areas of action have been outlined to reach net zero emissions, including:

  • The switch from fossil fuels to clean energy and clean energy products needs to accelerate in order to achieve net zero. Policymakers must shift subsidies and financial support away from fossil fuels to clean energy and low carbon technologies, cut tariffs on climate-friendly practices and goods, and take adequate measures to ensure a just transition.
  • Policymakers must support and incentivize first-movers in the fight against climate change, to help scale existing proven solutions and develop new sustainable technologies. Universally harmonized laws and regulations can help accelerate key technologies and sustainable best practices and encourage public adoption of low-carbon products.
  • Public and private investment is a crucial part of creating resilient supply chains and infrastructure that can help advance climate resilience, sustain food production, and secure water supplies.


While the international community has up to now placed particular attention on mitigation of climate change (i.e., human interventions to reduce emissions or enhance the sinks of greenhouse gases), Asif Saleh’s clear-eyed commentary posted by the Center for Global Development, makes a forceful case that mitigation should not preclude focusing on adaptation to current conditions, since much of the world, especially billions of people in low-income countries, are already bearing the brunt of its devastating impacts.  

In human systems (i.e., systems created and developed by humans, such as settlements, infrastructure, transportation, energy, economics, or health systems, as means to fulfill peoples’ individual and collective needs and wants), adaptation refers to the process of adjustment to actual or expected climate and its effects, in order to moderate harm or exploit beneficial opportunities. Human intervention may also facilitate adjustment to expected climate effects in natural systems (i.e., systems that occur in nature, such as circulation of water in the ocean, weather and climate, water drainage, energy cycles, forming ecosystems or community of plants and animals that interact with one another and with their physical environment--land, climate, soil, water, and nutrients).

As observed in an OECD report, while climate change mitigation and adaptation actions have been undertaken to a large extent separately in the past, there is increasing recognition that there are synergies that could be exploited more effectively to achieve climate resilience. The report suggests that identifying these opportunities can lead to better understanding, avoid trade-offs and develop policy measures and financing mechanisms that are mutually reinforcing.  In particular, the adoption, adaptation, and wide deployment of advanced technologies will be critical to mitigating the worst effects of climate change in the future, while  adapting to the change in climate in the short term..

How Does Climate Change Impact Human Health?

Climate change impacts a wide range of health outcomes.  Figure 1 illustrates the most significant climate change impacts (rising temperatures, more extreme weather, rising sea levels, and increasing carbon dioxide levels), their effect on exposures, and the subsequent health outcomes that can result from these changes in exposures.

Figure 1:

Impact of Climate Change on Health
Source: Adopted November 12, 2022, from CDC. “Climate Effects on Health”. Accessed at https://www.cdc.gov/climateandhealth/effects/default.htm.

The 2022 The Lancet Countdown report, published ahead of COP27, provides evidence that illustrates how this global crisis continues to escalate unabated, further aggravating the consequences of the COVID-19 pandemic and other mega threats—from severe economic downturns, fiscal and debt crises, war and geopolitical conflicts, displacement and migration, and increases in food and energy prices.

Similarly, to the explanation offered by Pope Francis’ Encyclical, the report clearly sums up the current predicament facing humanity:  environmental degradation and climate change are increasingly affecting the foundations of human health and wellbeing, exacerbating the vulnerability of the world's populations to concurrent health threats, while countries and health systems continue to contend with the magnified health, social, and economic impacts of multiple systemic risks.

The Lancet report provides robust evidence on health-related hazards, exposures, and impacts of climate change.  In essence, climate change is directly affecting human health globally with increased exposure to extreme weather and indirectly with impacts on the physical, natural, and social systems on which health depends. As noted in the report, climatic changes are also amplifying the existing threats to food and water security, infrastructure, essential services, and livelihoods. A brief summary of the key findings of the report follows, complemented by information from other sources:

  • Climate change is increasing the average global temperatures and the frequency, intensity, and duration of heatwaves. According to the National Oceanic and Atmospheric Administration, the past eight years have been the warmest on record, i.e., since 1880, with global mean surface temperatures (land and sea) diverging 0.82 to 0.99 degrees Celsius from the 20th Century average.  The exposure to extreme heat is associated with several health conditions (e.g., acute kidney injury, heatstroke, adverse pregnancy outcomes, worsened sleep patterns, impacts on mental health, worsening of underlying cardiovascular and respiratory disease, and increases in non-accidental and injury-related deaths).  Exposure to extreme heat also affects health indirectly by restricting people's capacity to work and exercise, particularly impacting the elderly and other vulnerable populations.  
  • Climate change is also affecting the distribution and transmission of many infectious diseases, including vector-borne, food-borne, and waterborne diseases.  With the increased movement of people and goods, urbanization, and climate change, for example, Aedes-transmitted arboviruses spread rapidly in the past two decades, and half the world population now lives in countries where dengue is present. The number of months suitable for the transmission of Plasmodium falciparum by Anopheles mosquitoes, that causes malaria in humans, in highland areas (≥1500 m above sea level) increased by 31·3% in the Americas, and 13·8% in Africa between 1951–60 and 2012–21. Non-cholera Vibrio bacteria survive in brackish waters and can cause gastroenteritis if ingested in contaminated food and potentially lethal wound infections if direct contact is made with contaminated water. Food insecurity is increasing globally, with 720–811 million people hungry in 2020, and climate change is exacerbating risks of malnutrition via multiple and interconnected mechanisms (e.g., due to social roles and reduced land ownership, women and the households they lead are more prone to malnutrition).
  • The Lancet report notes that the above impacts often occur simultaneously, exacerbating the pressure on health and health-supporting systems, and potentially triggering cascading impacts on the social and natural systems that good health depends upon. As estimated in this report, the economic losses associated with climate change impacts, compounding the synergistic effects of the COVID-19 pandemic and the international inflation and energy crises, are also increasing pressure on families and economies, further undermining the socioeconomic determinants of good health.  For instance, according to estimates done for the report, heat exposure led to 470 billion potential labor hours lost globally in 2021, with potential income losses equivalent to 0.72% of the global economic output, increasing to 5·6% of the GDP in low-income countries, where workers are most vulnerable to the effects of financial fluctuations.   Meanwhile, extreme weather events are estimated to have caused damage worth US$253 billion in 2021, particularly burdening people in low-income countries in which almost none of the losses were insured.

How to Build Resilience Against Human Health Impacts of Climate Change?

Progress towards net zero by 2050 must go hand in hand with a concerted focus on building the resilience of people, economies, and ecosystems. The Paris Agreement recognized the importance of enhancing adaptation and fostering climate resilience, and that adaptation in developing countries requires support (financial, capacity, and technological) from developed countries.  Health has been identified as a priority sector by all countries that have submitted National Adaptation Plan (NAP) documents to the United Nations Framework Convention on Climate Change (UNFCCC).

Focusing on climate change and the potential negative health effects and mounting a preemptive and sustainable response to limit their damage are critical to reduce societal vulnerability, build resilience, and contribute to the development of countries.   This requires that we in the health sector need to transcend traditional biological and medical constructs and adopt a broader biosocial understanding of health to focus on the direct and indirect health threats of climate change and adopt actions to protect communities from the detrimental impacts of climate variability and change.  

The adoption of broader paradigms such as the social determinants of health will help frame the debate and expand the scope for action by acknowledging the demographic, socio-cultural, environmental, economic, and scientific factors that determine health, disease, and the practice of public health and medicine.  At the global level, as observed by Julio Frenk, it will help us grasp the nature and characteristics of global transfer of health risks, the interdependence of health of populations, the unequal distribution of health challenges and resources across countries, and more importantly, how the global transfer of scientific knowledge and new technologies can inform and contribute to mount more effective responses to health challenges.

The broader understanding of health and disease will also enable us to develop more refined frameworks for action taking stock as the global population is projected to surpass 8 billion people on mid-November 2022, and its implications in terms of resource allocation, food security, climate change, other;    anticipating climate impacts and assessing vulnerabilities, estimating or quantifying the additional burden of health outcomes associated with climate change, identifying the most suitable health interventions for the identified health impacts of greatest concern, and developing, implementing, and evaluating climate and health adaptation plans. But, as observed by Juan Pablo Uribe of the World Bank Group, the economic cost of climate-related health risks is still largely missing, requiring an ambitious effort to quantify these costs.

Priority Health Areas for Action

In the health sector, climate adaptation requires building resilience in the health system and leveraging multisectoral action to develop healthy populations as strategic priorities to weather climate change and other concurrent external shocks, while preparing for and shaping health systems to respond to changing needs, demands, and expectations of the population.   Within this context, I believe that the following four thematic areas deserve priority attention to help identify interventions for inclusion and support under broader, cross-sectoral country climate change adaptation plans:

  • Build Resiliency in Health Systems.  The number and intensity of global health shocks, including those caused by changes in climate, are rising. The changes to the physical environment are expected to increase the total cost of health care service delivery. To help reduce vulnerability in countries, it is imperative that robust and resilient health systems are developed, coupled by health-related interventions across sectors. As highlighted in the 2022 World Bank Group report, “Change Cannot Wait: Building Resilient Health Systems in the Shadow of COVID-19”, building resilience in health systems requires integrated investments that promote progress toward the International Health Regulations (IHR) and Universal Health Coverage (UHC). These investments are needed to help countries prepare for, withstand, and manage acute health shocks and prevent disruptions in essential health service delivery during crises, meeting their responsibility with national populations but also to the global community.  This includes a focus on early warning systems; strong public health institutions (including legislation, planning, and decision-making for crises); cross-sectoral and public-private partnerships that strengthen coordination and joint implementation of activities; frontline, diversified, ready, and agile health workforce; risk communication and community engagement; and people-centered primary health care that is part of a strong, well-coordinated, and integrated service delivery continuum to respond effectively to the concurrent burden of infectious diseases, noncommunicable conditions, mental and substance use disorders, and injuries. As strong defenses can only be built on strong foundations, improving the mobilization and allocation of financial resources to ensure predictable and sustained budgetary allocations for core public health functions and other essential services, are critical foundations for building resilient health systems. Because of the health impacts of climate change, resilient health systems also need to lead decarbonization to prevent harming health, and health infrastructure needs to be updated to respond to extreme events, like heat and flooding.  Finally, as countries establish their monitoring, evaluation, and learning systems for adaptation, there is an opportunity to incorporate key indicators of health and climate-resilient health systems.
  • Focus on Social Determinants of Health.  While vector-borne diseases will expand their reach and death toll as a result of climate change, the indirect effects on potable water, food security, and extreme climatic events are likely to have the biggest negative effect on health conditions.  And, if these risks are not mitigated by preventing the further destruction of the environment by man-made actions and changes in climate, they will only exacerbate existing global health inequities, particularly affecting the poorest and least developed countries, by perpetuating poverty across generations, increasing malnutrition and ill health, causing premature mortality, and raising the specter of conflict, population displacement, and migration.  The implementation of a robust response, therefore, requires the adoption and adaptation of multisectoral approaches for health, that leverage different knowledge, skill sets, and resources and promote participation, collaboration, and consensus between governmental agencies, civil society, private sector, local governments, communities, and international organizations. 
  • Realize Environmental and Public Health Co-Benefits.  Under the Paris Agreement, countries committed to nationally determined contributions to a substantial reduction in GHG emissions until 2030 compared to 1990 levels. Measures to reduce GHG emissions can improve population health immediately and directly through reduced air pollution.  As observed by William D. Nordhaus, the Nobel Laurate-pioneer in environmental economics, solving the world’s biggest problems—from climate catastrophe and pandemics to wildfires and corporate malfeasance—requires, more than anything else, coming up with new ways to manage the powerful interactions that surround us. Tobacco-free investment, for example, is one way for investors to contribute to save millions of lives each decade, support climate action, reduce poverty, and boost development investment needed to construct a ‘new normal’ in the post-pandemic era.  While the devastating public health consequences of tobacco use are widely understood and documented, few people appreciate that tobacco also has profoundly negative environmental impacts as shown by existing evidence. Cigarette butts are the world’s most frequently littered item, with estimates that more than five trillion butts are discarded each year, ending up on beaches and in waterways. Tobacco filters – made of cellulose acetate - are the number one ocean plastic, more numerous than plastic bottles, plastic bags, or plastic straws. Butts pollute water ways where they dissipate into microplastics and enter the food chain. They also leach a dangerous suite of chemicals that place water quality at risk. Tobacco farming is highly water intensive, contributes to biodiversity loss, and causes 5 percent of deforestation in low- and middle-income countries, due to land clearing to grow the crops and procure wood for tobacco curing. When it comes to carbon emissions generated, tobacco has a similar footprint to entire countries.  Hence, tobacco-free investment is a way for investors to contribute to save millions of lives each decade, support climate action, reduce poverty, and boost development investment needed to construct a ‘new normal’ in the post-pandemic era. The Tobacco-Free Finance Pledge, launched on the sidelines of the UN General Assembly in 2018, calls on mainstream financial actors - across banking, insurance, pension plans, and asset managers – to integrate tobacco exclusions into investment, lending, and insurance policies. The pledge now has almost 200 signatories – major leading financial institutions, from more than 20 countries, with combined assets of more than US$16 trillion. While the Pledge focuses on tobacco, it intersects with and compliments many other important environmental initiatives, relating to ocean health, biodiversity, and deforestation, as well as to global public health initiatives such as the UHC agenda and the achievement of other health-related sustainable development goal targets.


As countries and the international community respond to the ongoing crises, there is an urgent need to integrate climate and development strategies to deliver green, resilient, and inclusive development.  This is key for reducing poverty and boosting shared prosperity globally and for minimizing the risk of pandemics and other societal catastrophes that cause widespread social, economic, and political hardship.

The nature and characteristics of health-related impacts of climate change should reinforce our understanding that the improvement of health conditions is not only about better access to medical care to treat the sick, or how we more efficiently finance health systems.  Above all, we need to be mindful that unless we pay more attention to issues surrounding life conditions, including the destruction of the environment and climate change caused by GHG emissions from human activities, and their linkage to poverty and ill health, our work will not help achieve healthy and longer lives for the population across the world.   

This means that if action in the health sector is not properly linked to mitigation and adaptation to climate change in countries and globally, and to other broader economic and social development efforts, it will not help address existing and growing global health inequities, particularly affecting the poorest and less developed countries. Indeed, climate change  impacts on the social determinants of health have the potential to magnify vulnerability among the poorest and most vulnerable communities, which are already easy prey to a variety of shocks—economic, health-related, natural disasters and armed conflicts—contributing to perpetuate poverty across generations; increase ill health, avoidable death, and disability; and undermining human capital development and hence economic innovation and competitiveness, employment, and wealth creation.

Focusing on climate change and the potential negative health sequelae and mounting a preemptive and sustainable response to adapt and limit their damage should be an integral part of the progressive realization of universal health coverage post-pandemic, critical to reduce social vulnerability, build resilience, and contribute to realizing the full economic potential of countries in the 21st Century. 

If policies and strategies are adopted by governments to reduce emissions and other short-lived climate pollutants, and individuals and communities feel responsible for and are actively engaged in their implementation, clear and measurable economic, social, and health benefits can be achieved.  

But, beyond scientific evidence and understanding, our resolve to do something to prevent the destruction of the natural environment and climate change, and hence their negative economic, social and health impact, has to be guided by moral conviction as well.  As Pope Francis’ Encyclical challenges us to do, we need to recognize that what is at stake is human life itself, and as humans, we have the obligation to defend it.  Therefore, it should be clear to all going forward, that the policy and investment decisions that governments and populations adopt and support over the short-and long terms to deal with climate change and other concurrent mega threats will ultimately reflect decisions on what kind of society a country wants to have.


Source of Image:  Stock Photo ID: 1302585244, “Toxic waste from human hands Industries that create pollution and cities that are affected by pollution”
Endnotes: [i] GHG is any gas that has the property of absorbing infrared radiation (net heat energy) emitted from earth’s surface and reradiating it back to earth’s surface, thus contributing to the greenhouse effect. Carbon dioxide, methane, and water vapor are the most important greenhouse gases.