London School of Hygiene & Tropical Medicine

Progress was made here in areas such as financing and emissions reductions, and the conference emphasised the broad impact of climate change with themed days for topics including youth empowerment and transportation.

Looking ahead, we need to add another themed day, dedicated solely to action on climate and health. With COP27 happening in Egypt, on a continent that will bear more than its share of the burden of inaction, the global community must not forget the link between the climate crisis and its growing implications for public health, particularly amid a continuing global pandemic.

As members of industry, academia and medicine, we recognise the extreme human and financial toll of this missed connection and ask policymakers to join us.

The relationship is well-documented: The past 20 years have seen numerous cross-sectoral studies on how climate change and its factors impact human health.

Recently the World Health Organization estimated that environmental factors — including air pollution, unsafe drinking water, zoonotic diseases, and weather-related disasters — cause more than 12 million deaths annually. Extreme weather claims lives directly and indirectly, putting food systems, infrastructure, and availability of care at immediate risk.

As environmental changes accelerate, global mortality is forecast to increase by at least 250,000 annual deaths from poor air quality and the geographic spread of vector-borne diseases like the yellow fever and West Nile viruses.

We also expect an increase in water-borne diseases such as cholera, due to more erratic rainfall and droughts. Importantly, deforestation and biodiversity loss have further increased the risk of other novel pathogens with pandemic potential.

Then there is the financial and economic toll. The annual global health costs already attributed to climate change and air pollution amount to trillions of dollars in welfare losses.

The global economy is starting to rebound after last year’s 3.5 per cent pandemic-induced contraction, but this recovery is expected to be uneven, in developed and developing economies.

Both climate and health factor into that inequity, with the World Bank predicting that 100 million people in emerging market and developing economies will have fallen back into extreme poverty by the end of 2021. That means disadvantaged countries will have even fewer resources to mitigate future climate impacts.

Aside from the climate impact on health, we must also address health’s impact on climate. Expanding essential health services to half the world’s population who lacks even basic access will require massive innovation and rethinking of care — in part because the sector represents up to 5 per cent of net global emissions.

The most resilient health systems therefore must be, or become, green, and the sector more climate-conscious going forward. That requires recognition of health leaders as major stakeholders in the climate agenda.

Governments can help facilitate dialogue to identify and invest in mutually beneficial opportunities.

COP26 already saw 42 countries, representing over a third of global healthcare emissions, commit to developing sustainable, low-carbon health systems. This is a laudable start, but more nations must join this effort to proactively enable the scaling-up of health services to mitigate climate-driven issues without inadvertently making them worse.

Similarly the private and charitable sectors must fully engage in driving a unified agenda. Significant changes to health systems’ workforces, financing, supply chains, and infrastructure will be essential in realising a green health future. Therefore, we also call on our peers to increase investment and cross-sectoral partnership, as well as to promote the climate-health link in development projects.

Ultimately, we owe it to the planet and its people to elevate and unify the climate and health conversations. Human health is rooted in planetary health and treating these as distinct undermines improvements to both. Indeed, the costs of keeping them separate are simply too great to ignore.

This piece first appeared in The Times Red Box.