The United Nations 26th Climate Change Conference, also known as COP26, is currently underway in Glasgow, United Kingdom (Oct 31-Nov 12, 2021). While governments and international organisations debate on the issues, it is pertinent for everyone to consider the effects of climate change on human health.

Global warming is a term used for the observed rise in the Earth’s average temperature and its related effects. Scientists are more than 95% certain that nearly all global warming is caused by increasing concentrations of greenhouse gasses (GHGs) and other human-caused emissions. The increase or decrease of GHGs determines whether the atmosphere retains or releases more of the sun’s heat.

Global warming is now reaching irreversible levels, and further increases will eventually result in an extinction-level event where all life on earth can end. Climate change is mankind’s single biggest health threat, and the harms caused by this unfolding crisis are being encountered by healthcare professionals worldwide. Carbon dioxide from fossil fuel burning, which accounts for two-thirds of GHGs, is the most important GHG in human-caused global warming. Scientists believe that three-quarters of the carbon dioxide emitted will not disappear for centuries to millennia. The other 25% stays forever.

The United Nations Intergovernmental Panel on Climate Change (IPCC) reported that the “average global temperature increased by 0.85°C from 1880 to 2012. Oceans have warmed, the amounts of snow and ice have diminished and the sea level has risen. From 1901 to 2010, the global average sea level rose by 19cm as oceans expanded due to warming and ice melted. The sea ice extent in the Arctic has shrunk in every successive decade since 1979, with 1.07×106 km² of ice loss per decade.”

“Given current concentrations and ongoing emissions of GHGs, it is likely that by the end of this century, global mean temperature will continue to rise above the pre- industrial level. The world’s oceans will warm and ice melt will continue. Average sea level rise is predicted to be 24-30cm by 2065 and 40-63cm by 2100 relative to the reference period of 1986–2005. Most aspects of climate change will persist for many centuries, even if emissions are stopped.”

The IPCC states that the world must limit temperature rise to 1.5°C to avert catastrophic health impacts and prevent millions of climate change-related deaths. Global warming of even 1.5°C is not considered safe, with every additional tenth of a degree of warming taking a serious toll on lives and health.

Effects on Health

Climate change is already impacting health in myriad ways. Some existing health threats have increased and new health threats will emerge. Not everyone is equally at risk, with factors like age, economic resources and location playing important roles.

With climate change, there is rising temperatures, more extreme weather, rising sea levels and rising carbon dioxide levels. This leads to extreme heat, severe weather, air pollution, changes in disease vector ecology, increasing allergens, impacts on water quality, impacts on water and food supplies, and environmental degradation. All these result in impacts on human health.

The graphic below provides an easily-understood pictorial summary of the various health conditions that can result from climate change.

Climate change affects the social and environmental determinants of health, i.e., clean air, safe drinking water, sufficient food and secure shelter. The undermining of many social determinants of health impacts on livelihoods, equality and access to healthcare and social support structures.

These risks disproportionately affect the vulnerable and disadvantaged, including women, children, ethnic minorities, poor communities, migrants or displaced persons, older populations and those with underlying health conditions.

An accurate estimation of the scale and impact of the health effects of climate change is currently challenging. However, with technological advances, the risks and scale of these health threats can be more accurately determined. These impacts will be influenced by a population’s vulnerability, their resilience, and adaptation in the short to medium term. Emissions reduction and the avoidance of breaching dangerous temperature levels will have an impact in the longer term.

The World Health Organization (WHO) has estimated that between 2030 and 2050, climate change is expected to cause about 250,000 additional deaths per year. These deaths are expected to be from malnutrition, malaria, diarrhoea and heat stress. Whether this figure will be revised to take into account the Covid-19 pandemic is a pertinent question. In summary, the effects of climate change on health impacts on healthcare facilities, with consequential effects on a health system.

Small Steps Matter

Everyone has an important role to play in reducing carbon dioxide emissions as little drops make an ocean. Remember the power of one. By making choices with less harmful effects on the environment, everyone can be part of the solution and influence change. It is essential, at the outset, to increase one’s knowledge and awareness of the impact of climate change on mankind.

Individual actions include:

  • Reduction of one’s carbon footprint by using less energy at home, driving less, using public transport, walking and bicycling
  • Reducing one’s food GHG impact by purchasing local and seasonal food, eating more plant-based meals, throwing away less food and composting any leftovers
  • Reducing, reusing, repairing and recycling electronics, clothes and other household items
  • Using solar or wind energy, if possible, and
  • Choosing eco-friendly products.

All sectors in society can individually and collectively contribute to a more rapid transition to a more climate-resilient environment through individual actions, as well as by speaking up, appealing to and encouraging the government, states, cities, towns, institutions and businesses to take urgent action towards net-zero emissions.

Dr Milton Lum is a past president of the Federation of Private Medical Practitioners Associations and the Malaysian Medical Association.

Article was first published in ‘The Star’ on 9 November 2021

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