Ever since climate change became an issue of concern there have been questions about the possible impacts on health. This month, two landmark reports have been released, both of which emphasise that a warmer, wetter world may well be a sicker one.
Together with Victor Galaz, professor of politics at the Stockholm Resilience Institute and a fellow partner in the STEPS-led Dynamic Drivers of Disease in Africa Consortium, I have been honoured to be among the contributors to a Lancet Commission report focusing on human health launched today. Earlier this month, a CGIAR report on climate change and agricultural pests, which I co-wrote with colleagues at the International Livestock Research Institute (ILRI), was published.
The 2015 Lancet Commission on Health and Climate Change was formed with the laudable aspiration to map out the impacts of climate change and the necessary policy responses to ensure the highest attainable standards of health for populations worldwide. Its worrying conclusion was that climate change is already having serious impacts on human health and these may get still worse. However, these challenges are also opportunities for the health sector to work in new and more inclusive ways.
Indeed, the central finding from the Commission’s work, was that health belongs in the centre of the climate change debate and that tackling climate change could be the greatest global health opportunity of the 21st century.
After documenting the impacts climate is already having on health, and discussing the future and indirect linkages, the Commission makes concrete recommendations for resilient health systems, safe cities and reducing the pollution from coal energy. Health should be built into adaption and mitigation strategies.
It also endorsed One Health approaches which involve collaboration across multiple disciplines and geographical territories to protect the health of people, animals and the environment.
The earlier CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) report on climate change and plant and animal pests was prepared as a submission to the UNFCCC Subsidiary Body for Scientific and Technological Advice (SBSTA). The SBSTA is responsible for marshalling the scientific evidence to support countries’ decisions that will be included in a global climate change treaty expected to be hammered out later this year in Paris.
The reports finds that, overall, in developing countries 20 per cent of grazing animals like cows and goats and 50 per cent of poultry are lost to disease each year, costing poor farmers about US$300 billion. And among the livestock diseases that most affect poor communities, more than half could be spread farther and faster by climate changes.
This is not surprising given that many animal pathogens either live in soils and waters, are spread by insect vectors or rodents, or pass from one animal to another when air humidity is high. As the world warms and gets wetter, conditions generally get better for diseases to flourish and spread. Pests and pathogens also tend to move polewards as colder areas become more hospitable and warmer areas get too hot. Extreme events, such as floods and droughts can allow sporadic diseases to become common.
At the same time though, it should be noted that tropical areas that are not poor, such as Singapore and northern Australia, tend to have disease levels comparable to non-tropical rich countries. Improved living standards, health care, public awareness and infrastructure are important for resilience in the face of diseases. These factors explain much of the elimination of many vector-borne diseases from the richer countries. For example, the elimination of malaria from Finland is believed to be dependent on socio-economic factors such as household size and living standards.
‘No regret options’
As someone once said, “prediction is difficult, especially about the future”. And predicting future disease patterns from the basis of largely unknown current distributions and epidemiology is highly challenging.
The Lancet Commission sets a good sign-post for uncertainty: the concept of “no regret options”. Many mitigation and adaptation responses to climate change are these no-regret options, which lead to direct reductions in the burden of ill-health, enhance community resilience, alleviate poverty and address global inequity.
Not everyone will agree on the trajectory or potential impacts of climate change on disease. However, all health and development workers can agree that disease, vulnerability, poverty and inequity should be part of humanities past – and not our future.
Dr Delia Grace is a veterinary epidemiologist at ILRI and a partner in the Dynamic Drivers of Disease in Africa Consortium.
Delia Grace and Victor Galaz will be speaking at the One Health for the Real World: zoonoses, ecosystems and wellbeing symposium, 17-18 March 2016.
- Read the ‘2015 Lancet Commission on Health and Climate Change’.
- Find out about the CGIAR report ‘Impact of climate change on African agriculture: focus on pests and diseases’.
- Find out more about the Dynamic Drivers of Disease in Africa Consortium.
- Find out how disease scenario modelling can help policymakers plan for climate change.