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‘Call on the health community to help meet the challenge’: Q&A with Catherine Machalaba

Climate change could cause up to 250,000 additional deaths per year by 2030, according to the latest World Health Organization (WHO) statistics. The environmental changes affecting our health are complex, myriad, and not always easy to predict, including changes in farming and forests, air pollution, and weather extremes of drought and flooding, calling on researchers to juggle multiple topics in search of solutions. We sat down with Catherine Machalaba, Science Officer for the ecoHEALTH project to look at what this means for the climate and health communities – and the message to policy makers meeting now at COP21. 

You’ve undertaken a review of how the upstream drivers of climate change – the processes that lead to greenhouse gas emissions – can affect human health. This builds on existing work on the effects of climate change on health. What does this new work reveal about how climate change processes interact with human health outcomes? 

Catherine Machalaba – Typically, climate change is viewed as an isolated environmental change that will exert pressures on health down the road. Our review showed that not only are health effects of climate change already being seen, but that the processes leading to climate change – such as deforestation, burning of fossil fuels, and major expansion of agriculture – result in adverse health outcomes. These processes also often cause or occur in parallel with other ecological changes that threaten global health, such as widespread land use change, population growth and subsequent resource demands to provide for an expected nine billion people, and rapid trade and travel that can move diseases around the world in less than a day. Without concerted efforts by the health community to address these drivers, our species faces a dire future health.  


What does this work tell you about the most pressing areas of concern? Can you make any generalisations about where the most urgent health concerns are arising?

Catherine Machalaba – We have to consider the immediate local impacts of climate change – such as increasing natural disasters where emergency responses are required – while also considering the long-term risks and preventive solutions that will promote global heath. For example, South Africa is currently suffering from its worst drought in over 30 years from extreme weather caused by El Niño, with devastating local implications for agricultural production, nutrition, and livelihoods. Globally, areas experiencing extreme drought conditions are projected to multiply by up to 30 times by the end of the century. So preventing future impacts will not only promote resilience but also lessen the heavy health and associated livelihoods burden that we face in upcoming years. 

The paper sets out a few examples of positive 'win-win' scenarios, where action on climate could be good for health and good for industry. Could you explain these? 

Catherine Machalaba – While sectors such as electricity generation, agriculture and transportation contribute to greenhouse gas emissions, the detrimental health effects of ecological change, including climate change, also extend back to industry and governments. That provides an incentive to work with stakeholders outside of the health community to find shared solutions. Active transport – such as walking and biking- is a clear example, allowing physical activity and promoting a low-carbon transit economy. Reducing pressures on ecological systems from natural resource extraction is another. For example, we can choose already-converted sites rather than disturbing primary forests to prevent the loss of carbon sinks or altered disease transmission dynamics. And the Ebola outbreak in West Africa has highlighted the need for building basic healthcare capacity and infrastructure in the region, including reliable access to electricity. Post-Ebola recovery and sustainable development investments can capitalize on low-carbon energy sources as a means to improve health systems infrastructure. 

You suggest that health concerns could be routinely built into environmental and climate risk assessments. Is this being done anywhere? What would this kind of assessment look like? 

Catherine Machalaba – To date, health, environmental, and climate data are typically collected and interpreted separately, preventing a full understanding of their dynamics. Health impact assessment isn’t routinely employed prior to a development project, so we often are unable to anticipate and act to prevent potential problems – and thus are stuck responding to disease rather than understanding what’s on the horizon. The good news is that the information we have access to is improving – for example, weather anomaly projections can now help us predict weather-related health risks (e.g. respiratory diseases from fires and haze, disease vector activity, etc.) ahead of time. We now need mechanisms to bring these groups together in a “One Health” approach, such as national inter-sectoral ministries who can pair information with public health action. 

World leaders are meeting at COP21 this week to hopefully hammer out an agreement on a low carbon future. If you could give one message to the negotiators, what would it be?

Catherine Machalaba – In our globally connected planet, the growing health effects of climate and intersecting ecological changes leave us vastly underprepared for disease outcomes on the horizon. While the charge of reducing our carbon footprint is enormous, it demands ambitious action from all countries and sectors for unprecedented success. Set firm carbon reduction commitments, and actively call on the health community to help meet the challenge. 

Further reading 

Machalaba, C., Romanelli, C., Stoett P., Baum S.E., Bouley, T.A., Daszak, P., Karesh, W.B., ‘Climate Change and Health: Transcending Silos to Find Solutions’, Annals of Global Health, Vol. 81, Issue 3, Pages 445–458