Toward planetary health

Author: Dr. Juan E. del Llano Señarís, director, Fundación Gaspar Casal, october 2022


The following reflection is based on the reasoned conviction that all of us, not expecting a decided response from governments that have not fully reached this point, must be more ambitious in the ecological transition we need to avoid reaching a point of no return, which would push our planet to be anything but healthy. To do this, we must change deeply rooted lifestyles. It is incompatible to meet increasingly urgent environmental demands while also maintaining old-fashioned development dynamics.

Pointing to environmental aspects

The Lancet Countdown(1) gives clear clues about the progress of health and climate change. It provides an independent assessment of the effects of climate change on health, implementation of the Paris agreement, and the implications of these actions on health. It continues the work started by The Lancet 2015 Commission on Health and Climate Change(2), which concluded that climate change threatens to undermine the last 50 years of public health achievements. On the contrary, a comprehensive response to climate change could be “the greatest opportunity to improve global health of the 21st Century.”

According to the WHO(3), over the last 50 years, human activities, and in particular fossil fuel combustion, have released enough carbon dioxide and other greenhouse gases to affect the global climate. The atmospheric concentration of carbon dioxide (gas that traps more heat in the lower layers of the atmosphere) has increased more than 30% since pre-industrial revolution times. In Spain we are witnessing a progressive trend towards higher temperatures, lower annual accumulated precipitation and broader and more frequent monthly thermal anomalies.

The Paris Agreement(4) marks a new era in climate cooperation, with responsibilities for the signers (183 countries). In the basis for the Climate Change and Energy Transition Law recently presented by Minister Rivera, Spain hopes to ensure the neutrality of greenhouse gas emissions by 2050, through an efficiency and renewable energy system by 2030 and 2050 (global and sectoral targets), providing tools that favor predictability, updating and coordination of the measures aimed at meeting the targets.All this, knowing the effects of climate change, adapting to them, guaranteeing territorial and social cohesion that permits a fair transition of the Spanish economy.

In a recent post in Nada es Gratis(5), Vicente Ortún points out that natural systems and health are moving in opposite directions. Our activity is causing biophysical changes at much more pronounced rates than ever before known in the history of our species. And these changes are produced in six fundamental dimensions: 1/ climate disturbance; 2/ broad contamination of the air, water, and soils; 3/ loss of biodiversity; 4/ reconfiguration of biogeochemical cycles, including those of carbon, nitrogen and phosphorous; 5/ generalized changes in land use; and 6/ scarcity of resources, including water and fertile land. Each dimension interacts with the others, altering the quality of the air we breathe, available water, and the foods we produce. These changes in living conditions affect our health and well-being, in nutritional aspects, infectious and chronic diseases, as well as migration and conflicts. Public health becomes planetary to include natural systems planning, urban development, energy production, nutrition and protection of biodiversity.

Xavier Labandeira, director of Economics for Energy, recently asked(6), how can we tackle climate change? In addition to adapting to it as well as possible, our fundamental control variable is the emission of greenhouse gases (GHG). Reducing these emissions is complex: firstly, because measures generate relevant socioeconomic costs and potentially adverse distributive effects (sectors that disappear, with the subsequent unemployment, short-term hikes in energy prices, etc.). Herein lies the first limitation in our fight against climate change. But, additionally, many policies could have a limited effect if the root of their origin is not affected: the infrastructure stock and installed capital, with associated emissions over their useful life. It goes on and on.

In addition, climate change is not directly caused by GHG emissions, but rather by their atmospheric concentrations. When the concentration level increases, our room to maneuver to control the problem is reduced. Even a world without emissions could be subject to great climate changes because, like before, the GHG stock that has been accumulating (over which we have only indirect control) plays a fundamental role. And that is without taking into account the possible natural feedback effects of exceeding certain concentration levels. In this case, we lose control of the problem.

Pointing to social and political aspects

We can affirm that Climate Change (CC) has gone from being a matter exclusively analyzed on its physical basis to being a social matter, due to its causes and consequences for societies. It is a sociological fact: it is one of the most important and severe problems facing contemporary societies. It is, also, a driving force of social dynamics. It must, then, be interpreted under specific cultural and conceptual parameters. To this end, there are two possible strategies: a first rational one that prevents “business as usual”, which perceives the negative side of CC as a limitation to growth and a reduction in survival opportunities. It is not an agent of change and does not alter society’s regulatory horizon. And a second strategy, which considers “business as usual” unacceptable, as guaranteed access to energy resources in the long term comes at the expense of fundamental human rights and the environment, with the use of violence or an undeniably unequal distribution of future opportunities. Here, CC is an actor in social change(7). In 2017, Ulrich Beck approached CC from the concept of metamorphosis: what was unthinkable yesterday, is real and possible today(8).

Some questions, perhaps a bit naïve: how much democracy can CC withstand? How much market can CC withstand? Are a market-driven economy and a determined climate policy compatible? Can democratic systems manage time limits and provide a response that meets the challenge? We see the negative trends accelerating and approaching a point of no return. CC must be prevented from becoming a social catastrophe or leading to social pathologies. Unchanging governments (USA), governments that have gone from denying to leading with a strong commitment to renewable energies (China) and the EU that sees this as an opportunity in terms of social identity and greater cohesion, are the pieces on a complicated chessboard. We must be able to go beyond an ever more emotional policy more disconnected from the source problems.

Machiavelli said that those who promote innovations are met with the opposition of those negatively affected by these changes, while the potential beneficiaries do not yet see the advantages of it all. This is very pertinent to climate change, as it affects the hard nucleus of our traditional way of understanding well-being and development. There has been a great imbalance between existential dilemmas and scientific and technological advances, with some political and institutional scenarios that maintain archaic and definitely non-functional behaviors. Priorities must be related to available resources and decisions must be made as to who will assume management of this change, combining strategy, citizen involvement, long-term and legitimacy.

Spain is a country especially vulnerable to climate change. In turn, we have the economic and technical means to contribute to global solutions, while facilitating the internal transformation to a more sustainable and higher quality production system. We must protect ourselves as a society from the great socioeconomic risks of not doing enough. To do this, it is convenient not to lose the room to maneuver, while it exists, thereby minimizing the social and economic costs of radical change that would have to occur sooner or later. Because such a demanding transition will only be possible if the costs to be paid are manageable.

Pointing to economic aspects

Humberto Llavador, John Roemer and Joaquín Silvestre, economists specialized in climate change, explore alternatives to the dominant paradigm of discounted utilitarianism, understood as current inseparable from well-being and distributive justice that seeks to satisfy preferences, determining the current value of a future payment. They evaluate climate policy using sustainability criteria and require that future generations have the same level of utility as prior generations, or that the utility grows at least at a fixed rate. They sustain that the greenhouse gas emissions generated by man jeopardize a global resource: a biosphere capable of sustaining life as we know it. They ask: What is the fair way of sharing this scarce resource among present and future generations, and in all regions of the world? They offer a new perspective based more on quality of life than just on consumption, as an ethical guide to sustainability and egalitarianism.

Sustainability, for these professors from UPF, Yale, and UC Davis, respectively, is understood as a pattern of economic activity over time that provides a set rate of growth of human well-being for an indefinite period of time. To achieve this, the atmospheric carbon concentration must be limited to a level not much greater than what exists today, approaching 450 ppm. In addition, they sustain that investments in education and research must be higher than current levels. International cooperation between developing and developed countries is also vital, because economic growth and climate change are interlinked.

The guiding principle of the agreement negotiated in Paris is that the dates by which living standards in developing countries catch up with those in developed countries should not be altered. They reach the conclusion that developed economies would have to agree not to exceed 1% annual GDP growth per capita, while developing nations should grow at a faster rate, but even lower than current projections, until they converge. Achieving such dramatic deceleration would carry political and economic challenges. The expansion of the concept of well-being beyond consumption leads us to respond to the challenge of climate change by moving away from energy-intensive goods and commodities towards less energy-intensive ones: knowledge, education and leisure(9). This immense chip change is not without its difficulties, but it seems there is no other alternative.

There is an agreed upon therapy for the fossil fuel addiction that could work: the agreed rates – price to pay for carbon dioxide emissions – $50 per ton in 2025 to $200 in 2050. The challenge is in building a global energy system that quadruples electrification, boosts hydrogen, eliminates hundreds of thousands of tons of greenhouse gases from the atmosphere, boosts renewables, etc. It is feasible; the technology is available, and will be cheaper if extensively adopted. It is, perhaps, the lack of political ambition that is missing. We have to think big, inside (and not just outside) the box, and embrace collaboration (we all lose if we don’t work together), but competition also becomes very important.

The plans of the Spanish Government (Climate Change Law, plus the National Energy and Climate Plan and the Fair Transition Strategy) require a total investment of some €238 billion through 2030. A large part of this investment is private, specifically 80%; the rest is public, in the amount of approximately €47.5 billion. We must assume that in the next 10 years, the budget will be capable of expending, in a context of deficit control, between 4 and 5 billion annually(10).

To reach the renewable target, 3,000 MW of new renewable power plants must be installed every year until 2030, assuming that nuclear production is maintained. Is it possible to build 3,000 MW annually of new power by 2030, and extract 4 billion annually in public funds over the same term? There is no clear and convincing explanation of how to obtain the money and transform electrical production.

The EU itself has estimated that investments to be made to meet these requirements, including a 40% reduction in greenhouse gas emissions set at the 2015 Paris Summit, will be on the order of €180 billion annually between now and 2030. Energy infrastructures, public transportation improvements, building efficiency or specific R&D are some of the areas in which European institutions may not only make their own investments, but may also stimulate investment from the private sector.

Pointing to health aspects

There is innumerable incontrovertible evidence that climate change, its anthropogenic origin, and its presence have an impact on health. The average temperature of the earth’s surface will increase between 1.1 and 6.4 degrees centigrade by 2100. Models also predict an increase in sea levels between 18 and 59 cm. The data on emissions and other events, as observed in 2008, show that the biodiversity of vertebrates had decreased more than one third in just 35 years (an extinction rate 10,000 times faster than in any fossil record) due in large part to the environmental crisis. We are facing a diabolical cocktail. The vertebrate population between 1970 and 2014 has dropped 60% and the number of species at risk of extinction has not stopped growing. Protected zones of the planet barely cover 15% of the earth’s surface.

The impact of climate change on human health will lead to great migrations that will harm health and lead to significant demographic changes. Future birth cohorts will be endowed with greater human capital, so the expected lower global fertility will potentially moderate ongoing climate change.

The worst climate scenarios will take place in the most disadvantaged and populated areas. Thus, population growth will interfere with the increase in desertification and the subsequent lack of food and water, the overpopulation of flood-prone coastal zones, and mass migration to large cities. It is estimated that the urban population in developing countries will go from 2.3 trillion in 2005 to 4 trillion in 2030, while the population in developed countries will remain at 1.2 trillion. The greater vulnerability in developing countries due to mass caloric restriction and the high prevalence of infectious diseases, lack of developed health systems and the lower adaptation potential, along with the lack of resources to adopt measures to mitigate the impact, indicate that the impact of climate change on health will occur, initially, primarily in Africa and Southeast Asia, and will lead to an increase in health inequality.

In relation to new scenarios of the health impact, it is estimated that by 2000, CC had led to the loss of 5.5 million DALYs (disability adjusted life years), a measure that combines premature mortality with disability, according to a panel organized by the World Health Organization(5). For example, it calculates that CC has caused a 2.4% increase in diarrhea and 6% to 7% in malaria during the 20th Century. However, this figure attributable to CC is lower than the estimated DALYs resulting from atmospheric pollution, and much lower than the nearly 40 million lost due to interior pollution in buildings in the same period. In any case, this estimate is considered conservative because it is based on the impact on cardiorespiratory diseases due to heat waves, diarrhea, malaria, and external causes as a result of floods and increased malnutrition.

Global climate changes carry a series of health risks, such as increased mortality due to extremely high temperatures, or a changing distribution of infectious diseases. From the equator to the poles, the climate and weather have great direct and indirect repercussions on human life. Extreme weather phenomena, such as heavy rains, floods or the hurricanes that devastated New Orleans (USA) in August 2005 and all the natural disasters in practically the entire world (the latest this March in Mozambique) jeopardize health and destroy properties and means of subsistence, and cause epidemics such as cholera. In the last decade of the 20th Century, natural disasters related to weather conditions produced approximately 600,000 deaths worldwide, 95% of them in poor countries.

Intense weather changes in the short term can also have a severe impact on health, causing heat stress or extreme cold (hypothermia) and causing an increase in mortality due to cardiac and respiratory diseases. The record temperatures reached in Europe in the summer of 2003 are associated. The WHO estimated 160,000 deaths per year attributable to climate change; in Europe alone, that summer, 70,000 more deaths occurred than expected. The WHO panel made forward-looking predictions suggesting that the impact would double by 2030, mostly due to effects on malnutrition, but the climate scenarios projected in 2000 have been shown to be very conservative.

Infectious diseases will increase due to the geographical spread of vectors and elderly mortality will increase due to more frequent heat waves; the greatest impact will be caused by indirect effects due to water and food availability, and catastrophes due to extreme weather situations, as we are seeing with great frequency. The uncertainty about the magnitude of the impact on health is due to the variation in emissions and warming scenarios that are being produced.

Climate change is the primary determining factor on health in the 21st Century. Some uncertainly about some of the predictions should not, however, be an excuse for inaction. Without a drastic reduction in carbon emissions, we will be doomed to the worst omens of the climate crisis. Policies aimed at reducing greenhouse gas emissions that promote health must be established. For example, the reduction in transport with motorized vehicles would involve increased physical exercise and, therefore, notable health benefits. In addition, a reduction in ruminant meat-based protein consumption would lead to a notable reduction in greenhouse gases (20% of which come from livestock activities) and would have a notable impact on preventing cardiovascular diseases and cancer(11).

Some progress is being made just in fighting pollution in cities, which are more nitrogen oxides, but it is not enough. In Europe, according to the European Environmental Agency, every year, 800,000 people die due to atmospheric pollution, nearly double the estimate.

Specific health programs must be created to tackle extreme climate situations, such as hurricanes or heat waves. The role of citizens is fundamental in building the social capital that will lead to the establishment of global policies that will bring about a profound cultural and productive change in the face of the serious environmental crises that are looming.

It must be emphasized that the panel organized by The Lancet and the University of London advocates for creating a movement in public health that addresses the threats of climate change to human health in its entirety. The recommendations of this panel of experts regarding a profound change in international policy, production, economics, urban planning and social organization indicate the extraordinary challenge it represents to tackling the environmental and climate crisis(1,2).

The relationship between health and temperature is not unchangeable, but rather is regulated by a complex number of economic, social, cultural and sanitary variables. The relationship between temperature and mortality is usually “V” or “U” shaped with a minimum temperature incidence that varies from one place to another, probably depending on the adaptation of the population to the temperature range to which it is exposed. The increased morbidity and mortality related to extreme temperatures constitutes one of the direct effects of climate change. A variable of particular importance is the aging index. As the population ages, it seems that the health effects of heat waves appear at lower temperatures.

In the framework of the European PHEWE project (Assessment and Prevention of Acute Health Effects of Weather Conditions in Europe), which includes Barcelona and Valencia, the possible increase in mortality in the 2030 horizon has been studied according to different IPCC scenarios, and it is concluded that the average attributable fraction of heat-related deaths will be 2%, with a greater impact on Mediterranean cities(12), predicting that this phenomenon will increase in the future according to the expected increase in the frequency and intensity of heat waves. Higher mortality increases have been obtained in other studies(13).

The effects will be ever more important and the impact of heat waves, which will be more frequent and more intense, will be greater for two reasons: the temperature will be higher and higher as a result of climate change and the threshold for triggering mortality will be lower due to the aging of the population.

In relation to the cold, it should be stated that the relationship between cold and health is also conditioned on social, economic and cultural factors, and how they will evolve in future climate change scenarios is unknown. Cold has a greater impact on mortality in places with more temperate winters than those with harsher winters, due to the physiological adaptation to low temperatures and the infrastructure of homes, which are made in better conditions to fight the cold in places accustomed to cold waves than in those where they are less frequent(14). The increase in average winter temperatures does not necessarily imply a reduction in the frequency or severity of extreme cold episodes. It is expected that the increase in heat-related mortality will be much higher than the slight reduction that can be expected from winter deaths(15).

Negative and positive impacts

It is not a matter of simplifying a complex fact by attributing the origin of extreme events to climate change, but it is a matter of highlighting and advocating that for which there is evidence: the link between these events and the constant emission of greenhouse gases. Extreme cold and heat. Chicago 40º below zero, Adelaide 46.6º. The rise of ocean temperatures increases the strength of hurricanes, droughts and wildfires. Feels-like temperatures of 50º below zero are incompatible with normal human and productive activity. Canceled flights, closed schools, empty offices, closed streets and highways, are a common scenario in recent winters in certain areas of the USA. Other negative impacts of climate change include: water stress in more and more areas of the world, a decrease in comfortable climate habitability in cities, risks to human health due to heat waves, an increase in diseases transmitted by infectious vectors and rodents, risks to tourism, coastal flooding and rising sea levels, and an increase in migration and political and social conflicts.

We can list the following among the positive impacts: the necessary increase in international and global cooperation, greater development of a legislative and institutional architecture, the possibility of changing economic growth models, the development of renewable energies and the increasing awareness of citizens about the significance of CC. However, the most impressive phenomenon is the students for climate movement. They have become the voice of conscience of adult generations who are demonstrating their inability to manage the present without leaving a legacy of destruction to future generations. They give credit to the science many leaders overlook. They show that education is key to the construction of a critical and responsible citizenry. The future of the planet depends not only on global decisions, but also on the individuals who avoid superfluous consumption, stop using disposable containers, travel on public transportation or recycle clothing. This new awareness flourishes in schools and institutes around the world.

Tackling global warming requires transformations of titanic dimensions. Jerry Brown, the governor of California, a pioneer on the subject, describes it in terms of a conversion: “It’s almost a quasi-religious transformation, that has not occurred, but should occur.” Its inclusion on political party platforms is essential, since, as Vinod Thomas(16), analyst of the Asian Development Bank, affirms, the window of opportunity for action is narrowing dangerously. With all of that, political action is not enough. So, connecting and using social media intelligently to what we know so far about climate change and the events that occur could help us recognize the priority and urgency of the problem, the impact it already has on our lives, and the shared responsibility of governments, corporations and citizens as consumers and voters.

According to Jeffry D. Sachs(17), the most urgent step now is to educate governments and corporations. National governments must draft technical reports on the capacity of their countries to put an end to greenhouse gas emissions from now until the middle of the century. And corporations and banks must urgently examine the strong technological arguments for the adoption of safe and non-polluting energy and food systems.

In conclusion

Unfortunately, emissions arising from the use of fossil fuels in transportation and industry are growing again. After a period of stagnation between 2014 and 2016, in 2017 they increased 1.6%, and in 2018 2.7%(5). As a result, the average temperature of the Earth’s surface has increased between 0.8 and 1.2 degrees Celsius.

The latest report from the UN scientific panel insists that we have only 12 years to prevent temperature increases beyond the Paris Agreement targets, which requires a 45% reduction in current emissions. The response capacity of renewable energies today, despite doubling every four years, does not cover the increased energy demand associated with economic growth. Political conditions are not conducive to optimism: the primary emitter, China, embraces and leads the Paris Agreement, but its emissions continue to increase; the US government does not believe in climate change. Only the EU is committed. Spain as well. But there is a lot of work to be done. Sociedad entre Pandemias(18), promoted by the Gaspar Casal Foundation and published in 2021, contains a multitude of critical reflections from various disciplines that point out keys to avoid repeating the mistakes made in the most deficient related aspects discussed by the authors. Therefore, in particular, the consideration that surviving the climate crisis is not an unattainable goal is very important, but for sustainable development, we need a sustainable withdrawal.

Today, still, we are not on a good path and one thing seems clear: the health of the human species will not improve on an ailing planet.


1. Watts, N., Adger, W. N., Sonja Ayeb-Karlsson, Yuqi Bai, Peter Byass, Diarmid Campbell-Lendrum, Tim Colbourn, Peter Cox, Michael Davies, Michael Depledge, Anneliese Depoux, Paula Dominguez-Salas, Paul Drummond, Paul Ekins, Antoine Flahault, Delia Grace, Hilary Graham, Andy Haines, Ian Hamilton, Anne Johnson, Ilan Kelman, Sari Kovats, Lu Liang, Melissa Lott, Robert Lowe, Yong Luo, Georgina Mace, Mark Maslin, Karyn Morrissey, Kris Murray, Tara Neville, Maria Nilsson, Tadj Oreszczyn, Christine Parthemore, David Pencheon, Elizabeth Robinson, Stefanie Schütte, Joy Shumake-Guillemot, Paolo Vineis, Paul Wilkinson, Nicola Wheeler, Bing Xu, Jun Yang, Yongyuan Yin, Chaoqing Yu, Peng Gong, Hugh Montgomery, Anthony Costello (2016). The Lancet Countdown: tracking progress on health and climate change. The Lancet.

2. Watts N, Neil Adger W, Agnolucci P, Blackstock J, Byass P, Kai W et al. (2015). Health and climate change: policies responses to protect public health. The Lancet Commissions, vol 386, Issue 10006, pages: 1861.1914. November 7, 2015.





7. Spain Report 2018. Cátedra José María Martín Patino de la Cultura del Encuentro. Coordination and publishing: Agustín Blanco, Antonio Chueca, José Antonio López-Ruiz and Sebastián Mora. Universidad Pontificia Comillas, 2018.

8. Beck U (2017). La metamorfosis del mundo. Paidós, Barcelona.



11. Sunyer J (2010). Promoción de la salud frente al cambio climático. Gac Sanit. 2010;24(2):101–102








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