Time to break a sweat over health and climate policy

Climate change will have direct effects on human health – especially as a result of diminishing food availability, heat waves, and the spread of disease. This could have real consequences for refugees and migration patterns if countries don’t act now, Jeremy Youde writes.

Last month, health officials from around the world came together at the annual World Health Assembly to set the agenda for the World Health Organization (WHO) for the coming years.

The delegates approved action plans to deal with both climate change and refugees separately – but going forward, the WHO, and all other international organisations, must consider the combined health effects of both.

Climate change will have a direct impact on human health in a number of different ways. Firstly, changing weather patterns will bring about negative consequences for food availability. If temperatures rise while rainfall decreases or occurs inconsistently, agricultural production will suffer.

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For example, the Midwestern US is currently experiencing its wettest 12 months ever, with massive flooding throughout the region. Farmers have been unable to plant their crops, and lower crop yields will lead to surging global grain prices, and increase food insecurity.

We’ve already seen this problem in East Africa, where droughts have reduced food production and have caused severe malnutrition – particularly among young children. Adequate nutrition and reliable access to food are absolutely key to human health.

Secondly, excessive heat from rising temperatures causes death and illnesses. Last summer’s heat wave killed at least 40 people in Japan and nearly 700 in the UK. A heat wave that also caused a power outage in Pakistan led to more than 60 deaths, with the lack of power also making it harder for people to cool off. Indeed, in the US, heat waves are now responsible for more deaths than any other natural disasters – and the problem is particularly bad in urban areas.

Thirdly, climate change alters where infectious diseases circulate. This is where the mosquito comes into play. Mosquitoes spread everything from yellow fever to Zika – but, at the moment, disease-carrying mosquitoes can’t survive everywhere.

Unfortunately, climate change will make more of the planet inhabitable for Aedes aegypti and Aedes albopictus, two of the most common disease carriers. Recent analyses suggest that these two species’ expanded habitat will threaten nearly half of the world’s population by 2050, meaning that we will likely see more cases of mosquito-borne diseases in new areas.

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It’s not just malaria, though. Australia and Pacific island states will be particularly hard hit by rising rates of malaria and dengue as mosquito populations spread. Cholera can take advantage of high temperatures and excessive rainfall and take root in areas with poor sanitation.

Climate change can also alter animal habitats, making it easier for animals to communicate diseases to humans. Scientists worry that cases of the Hendra virus, a disease which spreads from flying foxes to horses to humans, is likely to increase as climate change alters the living conditions for flying foxes.

How will any of this matter for migration flows? We know that refugee patterns are the result of complex arrays of factors, and climate-induced health changes will add to these stressors. We also know that refugee and internally displaced populations already face worse health outcomes. It’s not that they are inherently unhealthy; rather, they face substantial challenges accessing healthcare services.

Two issues are key when understanding the link between climate, health, and migrant health. To begin, forced displacement due to natural disasters can upend health services. When Hurricane Maria hit Puerto Rico in September 2017, people were forced from their homes and faced a range of health challenges in the aftermath of the storm. Overcrowding, poor sanitation, and a lack of healthcare have all posed long-term threats to the island’s population.

On top of this, urbanisation introduces its own set of health challenges. Rapidly urbanising cities rarely have the necessary sanitation infrastructure, and health services may be widely unavailable. As people stream into cities to flee the effects of climate change, those cities may not be able to facilitate them and their health needs.

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To tackle these interrelated problems, we need to harness a broad global commitment. Countries must embrace the One Health approach, recognising the interconnectedness between human, animal, and environmental health. Without also addressing these other domains, the world won’t be able to address human health.

We must also build cross-cutting alliances among states, international organisations, and non-governmental organisations to tackle these challenges.

The health effects of climate change and their impact on migration do not neatly fit under the capabilities or responsibilities of a single organisation, and we need to draw on a wide range of expertise to tackle such wide-ranging challenges.

Finally, and perhaps most importantly, however, we must start addressing these issues now – before the situation gets any worse. The longer we wait, the larger the problem will become, and the harder it will be to address. More than ever before, the world is in need of strong policy and leadership.