Health and climate change


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NOT only have we messed up, but have also created a royal, unmitigated disaster, perhaps irretrievably – a point made brilliantly in the book Naturally by Vikram Soni. Exhaust from our automobiles has contaminated U-235 crystals, refrigerator coolants have burned a hole in the ozone layer, popcorn flavouring has killed people via lung disease, and eating meat and playing golf have left huge, consequential eco-footprints. As a result of these and similar actions, our oceans are in dire straits (if oceans can be in straits), our groundwater is less grounded, and we cannot see the forest for the trees have disappeared. Gas, both from fossil fuels and from the flatulence of cows, is producing climate change.

‘Naturally’ leads us by the hand, step by step, with lucid explanations, through this landscape of devastation. We have done it to ourselves. Perhaps unwittingly, perhaps fecklessly, we are our own worst enemy. Through technological innovations that have disrupted the stability and balance of our ecological and social systems, through consumer excess, and through our growing narcissistic zeal, we have wreaked – in fact, are wreaking – havoc.

And yet there is a distal, abstract, almost academic, if not unreal, sense of impending doom. At one level, ignorance and denial are the basis of an ostrich-like response. What is the causal chain between the use of a spray deodorant and a hole in the ozone layer? How does driving down the road produce a tsunami? Or drilling for oil and gas start an earthquake? At another, the time horizons for solutions and fixes also result in a feeling of distance. For example, in the Paris Accord on Climate Change, mobilizing $100 billion a year will happen by 2020, the first stocktaking will take place in 2023, nationally determined contributions will be reviewed in 2025 or 2030, and so on. While these plans may be realistic and pragmatic, they produce a sense that things will happen ‘down the road’, obscuring the direct connections in the here and now. An overarching sense of immediacy and urgency of these issues in our personal lives is lacking. For the most part, we continue our lives as usual.

An area where we are being affected by environmental changes, including climate change, is health, both physical and mental. As noted in ‘Naturally’, ‘a consensus is emerging among scientists, ecologists and human health experts that …strains of avian flu, besides diseases such as monkeypox, HIV/AIDS, West Nile virus, Ebola, SARS, BSE, and Lyme disease, are emerging and crossing more easily to humans because of environmental changes and the intensification of farming.’ That is, there is growing evidence that changes in the environment are killing us.


Today. Right now. It is true that there are disparities in the impact, with low and middle income countries being disproportionately affected, but models suggest that, over time, with global warming, that could change. There is immediacy in how we can be affected, based on where we travel, or what we eat. The point is that if one approaches these larger, slower, environmental changes through the lens of our own health and mental health – that is our own personal well-being – this may be more likely to compel needed changes than the arguments of planetary well-being. Or as Helena Wang and Richard Horton put it in a Lancet article: ‘When climate change is framed as a health issue, rather than purely as an environmental, economic or technological challenge, it becomes clear that we are facing a predicament that strikes at the heart of humanity. Health puts a human face on what can sometimes seem to be a distant threat’ (italics mine).

Essentially, health and climate change/environmental factors can be viewed as two sides of the same coin. At one level, climate change is described as the biggest global health challenge of the 21st century. At another level, paying attention to health, by necessity, will imply changes to environmental factors.

This article attempts to explore and elaborate this perspective. First, the emergent evidence of the impact of the environment on health is reviewed. Then, using the Zika virus as an illustration, the point made is that viruses are not happening to us but that we are creating the conditions and the mechanisms for such viruses to thrive. And, finally, in the last section we look at what might be done on the health and mental health front to make headway on issues related to climate and environmental change.


According to a recent (March 2016) WHO report, an unhealthy environment accounts for nearly one in four of all global deaths. An estimated 12.6 million people die as a result of living or working in an unhealthy environment. According to the report, environmental factors such as air, water and soil pollution, chemical exposures, climate change and ultraviolet radiation, contribute to more than 100 diseases and injuries.

Most of these deaths – two-thirds – are due to non-communicable diseases (NCDs) such as stroke, heart disease, cancers and chronic respiratory disease, and are largely attributable to air pollution. Associated with NCDs are mental illnesses such as depression and anxiety. A significant proportion of persons with heart disease, stroke and asthma have these concomitant mental disorders. According to the latest research, the causal relationship appears to be bidirectional: persons with depression and anxiety are more prone to getting heart disease and other NCDs than the general population. According to WHO, depression was ranked as the third leading cause of the global burden of disease in 2004 and is projected to move into first place by 2030. That is, these environmental factors are not just affecting our bodies but are impacting our minds as well.

At the same time, deaths from infectious diseases such as diarrhoea and malaria have declined. The increase in access to safe water and sanitation is a key factor explaining this decline, together with immunizations, essential medicines and mosquito nets.

Low and middle income countries are the most affected, with countries in Southeast Asia and the Western Pacific regions having the largest environment related disease burden. Population-wise, environmental factors have the greatest impact on young children, especially those under-5 years, and older adults. Children are most affected by respiratory diseases and diarrhoea while older adults are mostly affected by NCDs.


The report is sobering as it painstakingly examines the health impacts of environmental risks on more than a hundred diseases. Some of these environmental factors are well known such as unsafe drinking water and sanitation, and air pollution and indoor stoves; others are less so, such as climate change and the built environment. The heartening aspect of the report is that when these relationships are consciously recognized, good things can happen.

Smoke-free environments reduce cardiovascular disease and respiratory infections. Improving urban transit and urban planning (e.g. more green spaces, pedestrian walkways, waste recycling) and building energy-efficient housing reduces air pollution-related diseases. For example, Curitiba, Brazil has invested heavily in such initiatives and, as a result, despite a fivefold increase of population in the last 50 years, air pollution levels are lower compared to other rapidly growing cities and life expectancy is a couple of years longer than the national average. Amarapuri, Nepal identified open defecation as a water quality hazard: toilets were built for each household and the village was declared an ‘open defecation free zone’.

Despite these success stories and sufficient scientific evidence, the challenge remains for us to recognize that we are killing ourselves, our children and grandchildren. We need to recognize that what we are doing, both in terms of policies and in terms of individual choices, are acts of unwitting suicide. Instead of the Gaia (the Greek Mother Goddess) hypothesis we should be ingesting a gaya (the Hindi verb to go) hypothesis so that it becomes a fundamental aspect of our way of thinking and living. As ‘Naturally’ so vividly points out, we need to be making these connections. And, as the next section illustrates, we need to make the connection not only about how we are killing ourselves, but also how we are creating an arsenal by which to kill ourselves.


The Zika virus has been in the headlines for the last several months after it was declared a global public health emergency. The virus is associated with brain deformities in babies born in South America where several thousand cases of microcephaly (babies with smaller than average head size) have been reported. The Zika virus is transmitted to people primarily through the bite of an infected Aedes species mosquito, the same mosquito that spreads the dengue and chikungunya viruses. Mosquitoes become infected when they feed on a person already infected with the virus, and they can spread the virus to other people through bites. No vaccine exists for Zika.

A mother already infected near the time of delivery can pass on the virus to her newborn. Similarly, a pregnant woman can pass on Zika to her foetus during pregnancy. Zika can also be spread by a man to his sex partners. Hence, all the travel restrictions to Zika-infested areas for pregnant women, and restrictions and cautions about having sex with persons who might have been exposed to Zika.

The strikingly singular fact about the Aedes mosquito is that it does not live in natural habitats such as swamps, forests or on the ground. Instead, the mosquito thrives in human-made habitats such as tires, cans, plastic containers and rain barrels. As Durland Fish, a professor of microbial diseases at Yale University puts it, ‘Humans have created an environment for it to proliferate.’


Researchers are making the case that environmental degradation, uncollected garbage, discarded tires filled with water, areas of undrained water have created habitats for mosquitoes that then spread the deadly virus. There are many factors that contribute to the emergence of Zika but some of the principal drivers identified have been human population growth, unplanned urban growth, globalization, and the lack of effective vector control.

Building dams, deforestation, and global warming are other environmental factors that have been shown to make disease vectors worse. As with all mosquito borne viruses, climate is a factor that influences Zika transmission. In general mosquitoes do not live long – 10 to 12 days – which is about how long it takes a virus to grow in the mosquito. Often, the mosquito dies before it can spread the virus. However, when it gets warmer, the virus incubates faster, and the insect has more time to be infectious. Warmer temperatures also make the mosquito hungrier; so it takes more ‘blood meals’ and thereby spreads the disease to more people. In Brazil, the higher than average temperatures there are associated with the Zika outbreak.

Climate change will only increase the spread. As global temperatures rise, the land area covered by the Aedes mosquito is projected to increase from 5% to 16% in the next two decades, and to 43%-49% by the end of the century.

Professor Fish argues that we have to start focusing on how the environmental changes we bring about – involving dams, forests, and so on – change the ecology of diseases. That is a different way of thinking about health and diseases. The medical world tends to pursue cures like vaccines rather than ecological understanding that can lead to better prevention.

In her book, Pandemic: Tracking Contagions, from Cholera to Ebola and Beyond, Sonia Shah cites a study in which 90% of the epidemiologists surveyed say they believe a global epidemic will sicken one billion and kill up to 165 million within the next two generations. The same conditions that drove cholera – population density and mobility, political corruption and inertia, unsanitary waste disposal, international travel and transportation – are what drive pandemics today. All this is complicated even further by climate change which is changing the migration patterns of birds and what gets transported in warmer ocean waters. Shah suggests that the real danger with pandemics is to treat them as inconveniences rather than the crises that they really are.

The moral of this cautionary tale is that the way we live is also the way we die. The way we live is also the way we create the paraphernalia and parasites to destroy future generations. In a strange, ironic twist, the microcephaly associated with the Zika virus is almost a metaphorical admonition or retribution for human big headedness.


The ways by which climate change can affect health are both through direct and indirect mechanisms, and the ultimate impact depends on how these mechanisms interact with social factors related to individuals as well as the existing infrastructure and resources that are brought to bear. As the Lancet Commission on Health and Climate Change report points out, changes in extreme weather and resultant storm, flood, drought or heat-wave are direct risks. Indirect risks are mediated through changes in the biosphere, e.g. changes in disease vectors a la the spread of Zika described above, or the availability of food. Social factors relate not only to the social determinants of health and system capacity but also to social processes such as migration and conflict. To capsulize, the health effects of climate change are: death and injury from extreme weather events; the impact of global warming related to increased temperatures and heatwaves; the spread of new (and old) vector-borne diseases; asthma and other respiratory illnesses; and changes in food and water quality and availability.


Similarly, climate change is projected to have direct and indirect effects on mental health. The relationship between weather and mental health is well established: Seasonal affective disorder (SAD) is a form of depression that is seasonal in nature, and is usually associated with moodiness and low energy in the winter months but, less often, SAD can also cause depression in the spring or early summer. Experts are not sure what causes SAD, but it may be related to the lack of sunlight or a disruption in sleep patterns. On a daily level, research suggests that climate related factors such as temperature, sunlight, wind and rain have no significant impact on positive mood but that some of these factors do have an impact on negative mood. Increased temperature had a positive effect on negative mood, while increased wind and decreased sunlight had a negative impact.

Higher temperatures have also been associated with higher rates of violent crime. In one study, both inter-group violence as well as interpersonal violence (which includes rape and domestic violence) increased with temperature increases. Higher temperatures have also been associated with higher suicide rates, but in some cases, these rates may be affected indirectly by the economic impact of droughts and crop failure. In India, farmer suicides are substantially higher than for the general population, and in states worst hit by drought, these rates were more than double. (It should be noted that these farmer suicides have been high even when the crop has been excellent. However, the rates increase substantially in years of drought.)


Mental health is also affected indirectly by climate change as natural disasters and catastrophes occur. The loss, disruption and displacement that may be a consequence of the disaster can cause acute stress and, in some cases, result in chronic post-traumatic stress disorder (PTSD), as well as depression, anxiety, somatoform disorders, and drug and alcohol abuse. For example, research conducted in communities affected by Hurricane Katrina in the United States showed high rates of depression, domestic violence and higher rates of suicide attempts and completion. The bottom line is that the extreme weather events, sea level rise, destruction of existing economies and the resource scarcity and maldistribution that have been associated with climate change will also have a tremendous impact on mental health.

The objective here is not to paint a scenario of doom and gloom but to underline the point that there is an immediate self-serving urgency in addressing issues related to the environment and climate change. When one looks at climate change through the lens of health, there is a direct, tangible link between changes in the planet and oneself. The argument here is that the health of the planet in inextricably intertwined with one’s own health. In fact, one way to put it: The health of the planet is my health.

We still have a long way to go to make the environment and the climate to be culpable for our early death or ill health. The cause of death on the death certificate is lung cancer or stroke or heart disease or Ebola, not air pollution or global warming. But making this connection has to be part of the solution and part of our future if we are to make headway.


The Paris Accord has raised the ante. The accord brings all countries together in a single agreement on tackling climate change. There is a consensus among 200 countries that greenhouse gas emissions must be reduced; $100 billion a year has been pledged; individual nations have committed to making specific contributions to achieve the goals that have been set; assessments will be made every five years, starting in 2018. But the national pledges made so far will not get us to the goals set. The national pledges are voluntary; the monetary commitments are considered to be insufficient. That is, while commitments have been made, there is considerable flexibility in terms of actual adherence. In a sense, at best, the Paris Accord is aspirational; at worst, it is lip service to an unavoidable, pressing global concern. To ignore climate change would be aping the ostrich. The Paris Accord is a huge first step, but much more is needed.

From a health perspective, Margaret Chan, Director-General of WHO, identifies three priority areas. First, to scale up climate resilient health systems: these systems would include specific measures to adapt to a changing climate such as early warning systems for more frequent and severe heatwaves, and protection of water and sanitation against floods and droughts. Second, to focus on health implications of energy systems, given that WHO documents that over seven million deaths a year are attributable to air pollution. Third, there is a need to highlight mechanisms for monitoring and assessment of progress. Here we humans could be the canary in the mine: if we are still dying of air pollution we can surmise that we have not made progress addressing climate change.


The logic of these solutions is laudable. The logic in the arguments for solutions is impeccable. But as countries try to implement solutions to address changes in the environment, real dilemmas arise. Is it better to invest resources in fighting the effects of climate change, or in helping people to adapt? Vietnam, for example, has just started its biggest ever engineering project of building a network of walls to hold back rising sea levels that are swamping fertile rice growing areas. The project will add up to hundreds of miles of walls and take 40 years to build. Another approach is to accept that the Mekong delta may not be the best place to grow rice but may be optimal for shrimp.

But, even as we stumble and grope for what needs to be done, what appears to be missing is the ethos factor: issues of the environment and climate change have to become part of our value and belief system. They have to become an integral part of our culture. Both the Dalai Lama and Pope Francis have made the point that action against climate change is a question of ‘the survival of humanity.’ We have to incorporate this perspective in our daily lives.

At the beginning of April 2016 a new report, The Impacts of Climate Change on Human Health in the United States: A Scientific Assessment, was published, warning of widespread risks to public health from rising temperatures in the coming decades from increased deaths and illnesses associated from heat stroke, respiratory diseases and diseases such as West Nile virus. According to Vivek Murthy, the U.S. Surgeon General, climate change is a far more challenging threat to public health than even the polio epidemics in the past. Polio was eradicated with a specific vaccine. ‘Climate change is not like that. There is not one single source we can target’, he went on. ‘As far as history is concerned this is a new kind of threat we are facing. I don’t think we have seen something like this before where we have a force that has such a multitude of impacts.’


Despite the dire implications and warnings, from the perspective of the general public the report is a story in one of the inside pages of a newspaper that is duly noted, if that, before the page is turned. Despite the science and the evidence, activities are in the ‘consciousness raising’ phase, in the phase of increasing public awareness and rallying public support. Nevertheless, the impact on health does seem to be a mechanism to move the needle on what needs to be done regarding the environment and climate change.

The book Naturally: Tread Softly on the Planet makes the telling point that, for the first time in human history, the scale of human intervention has exceeded the scale of the planet. The accompanying planetary mayhem and jeopardy is evidenced in species loss, climate warming, the ozone hole, Arctic and Antarctic melting to name a few events. As our important natural living resource or survival resource is rapidly declining we will have to act to save ourselves. Natural living resource conservation then transforms from altruism to our only survival strategy. Soni suggests, natural cycle technology and tangible ‘conserve and use’ solutions to make this change. Interestingly, he points out that such solutions can carry economic and health benefits as well. Perhaps, changing to a non-invasive living scheme is a possibility; how can we make it become a reality?


At the same time, the solution cannot be based on individual choices alone. Individual choices have to be translated into a cultural value that, in turn, drives policy in real, significant terms. This involves education and ‘consciousness raising’ on an ongoing basis in the long haul. In ‘Naturally’, Soni presents the concept of three identities as a construct to the development of such a cultural value. Each of us has a personal identity as an individual and, by definition, a social identity as an individual within a societal context, and a planetary identity as an inhabitant of this planet earth. Beyond our own individual interests, we have a responsibility to society and the planet at large. It is time to change our scheme of living and our ideology to be holistic – we have persisted too long with outdated and invasive ideologies. ‘Naturally’ suggests the framework in which monopolistic individuals do not invade the rest of society and the over consuming society does not consume the planet – a more holistic view of health includes a healthy society and a healthy planet. The question is: How are we to cultivate and nurture this sense of responsibility?

Symbolic consensus as represented by the Paris Accord is a necessary first step but is inadequate as a solution, largely because of the caveats and its permissiveness to fail. Even though individual decisions and choices are important, ultimately it is policy decisions and the enforcement of regulations that are going to make a difference. But how to move policy meaningfully? Powerful interests are invested in the status quo; it is the age of the self. (Hence the equivocation in the Paris Accord.) The only way to move policy is for people to recognize the urgency in the following equations: Environmental Health = My Health. Planetary Health = My Health.

We have to recognize that climate change and global warming are affecting not only human health but also the health of other systems such as coral reefs, and coral reefs are essential for the oceans’ ecosystems, supporting fish stocks that feed more than a billion people. That is, the health of the coral reef = my health. Only with such recognition will public pressure push policy on a fast and meaningful track.

Being skeptical by nature, I do not think the current adult generation is ready to take on the responsibility because they are too caught up in the inertia and demands of their lives. A productive avenue is to inculcate and embed these values in children. A primary target should be children so that they grow up with a sense of the importance of the environment in their lives. Perhaps climatology and ergosophy need to be core subjects in school like arithmetic and history. Right from the start, children need to grow up with a sense of their societal and planetary selves as an integral part of their being.

There is no question that the children of today will have a vital part in being the solution. It is their planet. As UN Secretary-General Ban Ki-moon puts it: ‘There is no plan B; there is no planet B.’ As always, the perennial question remains: To B or not to B.