These 3 climate disasters will have the biggest impact on human health by 2050

Extreme weather events could become the biggest global risk over the next decade. One of the main areas where this will be felt is global health, according to a new report from the World Economic Forum and Oliver Wyman.

Quantifying the Impact of Climate Change on Human Health analyzes climate-driven events including floods, droughts, heat waves, tropical storms, wildfires and rising sea levels for their direct and indirect impact on health.

It predicts that by 2050, the climate crisis could cause an additional 14.5 million deaths, $12.5 trillion in economic losses and $1.1 trillion in extra costs to healthcare systems around the globe.

The new report emphasizes the impact of rising temperatures and extreme weather events in terms of exacerbating infectious and cardiovascular diseases as well as respiratory and other ailments.

It also highlights that health issues related to climate change will disproportionately affect already vulnerable communities. This includes women, young people, the elderly and lower-income groups, especially among developing economies in Africa and Southern Asia. Here, existing health inequities such as resource limitations, inadequate infrastructure and a lack of medical equipment will be further exacerbated by the effects of climate change.

Here are the three most acute climate risks for global health.

Floods pose the highest acute risk of climate-induced deaths. Floods could take as many as 8.5 million people’s lives by 2050, according to the report.

With sea temperatures rising, the amount of water evaporating rises and causes polar ice to melt more quickly, adding to total rainfall and increasing water table levels. Coastal areas are particularly exposed to flood risk as sea levels rise, with tidal flooding now up to 10 times as frequent as it was 50 years ago.

Aside from fatalities and injuries, stagnant water after flooding encourages the expansion of waterborne and vector-borne diseases (those carried by living organisms, such as malaria). Damage to infrastructure and crops can lead to food insecurities and malnutrition. In addition, floods can dramatically affect people’s mental health as they cope with the loss of homes and livelihoods.

Global projections show that equatorial regions in South America, central Africa and coastal regions of South-East Asia could be the worst affected by rising flood levels by 2050.

Droughts – prolonged periods with very low or no rainfall – represent the second-highest cause of mortality. By 2050, they are expected to cause as many as 3.2 million deaths.

While we may associate droughts with regions such as Africa – where 40 million people are exposed to their impact – droughts are also increasingly felt in more temperate areas of the world. Close to 40% of the mainland US and nearly a fifth of people in Europe face droughts.

Reduced water quality and availability and soil degradation are immediate consequences of drought. They can lead to instances such as higher concentrations of dust, which may result in a rise in respiratory diseases. At the same time, they will affect both food security and hygiene and sanitation, which can lead to malnutrition and favour the spread of infectious diseases. Droughts also put at risk livelihoods, with mental health issues adding to the health impacts.

Future high-risk areas for droughts are the west of the US, South Western South America, the Mediterranean region and south-western Africa. Many of these regions are already experiencing deteriorating precipitation and lower groundwater levels, according to the National Oceanic and Atmospheric Association’s (NOAA) Drought Information System.

Heat waves are prolonged periods of extreme temperatures and humidity. The report finds that these have the greatest economic impact, estimated at $7.1 trillion by 2050. These losses are mainly a result of lost productivity.

Heat waves are increasingly prevalent across the globe, affecting the body’s cooling system. Prolonged periods of heat can lead to a multitude of health issues, including heat exhaustion and electrolyte imbalances. Some of these outcomes can be life-threatening, especially in vulnerable people, where the additional strain on the body can lead to heart attacks or strokes. Poorer populations are disproportionately affected, for example where there is limited access to freshwater and air conditioning.

From an economic perspective, heat waves greatly affect occupational health and productivity, especially in professions that are particularly exposed to heat, such as agricultural or construction workers.

By 2050, heat waves are forecast to account for nearly 1.6 million deaths – mostly in the highest-risk areas, including the US, Central America, southern and western Africa, the Middle East, India, South-East Asia and northern Australia. These regions may see their heat exposure go up 12 to 38 times, with growing urbanization a key contributing factor. This is because city buildings, roads, pavements and other amenities all absorb heat and then re-emit it to a much greater extent than nature does.

For healthcare systems the world over, dealing with the health impacts of the climate crisis adds further challenges when many of them are already stretched.

The World Economic Forum and Oliver Wyman suggest that two areas need particular attention to make them resilient: preventing or reducing the health impacts of climate change and the ability to recover quickly from a climate event when it does happen.

Achieving this will take a conjoined effort – by governments, policymakers, the life sciences industry and the healthcare sector itself. However, more fundamentally, the report concludes, governments and industry must do their utmost to cut greenhouse gas emissions to prevent a downward spiral in the first place.