London School of Hygiene & Tropical Medicine

As the world continues to face myriad health challenges, including the ongoing COVID-19 pandemic, it is significant that for the first time the World Health Organization (WHO) has chosen to focus this year’s World Health Day on the theme “Our Planet, Our Health”.  

Although the health impacts of climate change are increasingly being recognised, health has generally been peripheral to climate change policies and negotiations. As we approach COP27 later this year, WHO’s campaign signals it is time to change that.  

According to WHO, climate change is the greatest single threat to the health of humanity. Climate change poses severe risks to physical and mental health through many pathways including by increasing exposures to extreme heat, floods, droughts and wildfires. The incidence of food and water-borne diseases and of vector-borne diseases such as dengue are also affected. The yield and nutritional quality of crops, including of fruit and vegetables, are projected to decline, contributing to increasing undernutrition. Extreme weather, land degradation, and water scarcity are projected to drive the displacement of populations.  

According to one of the latest IPCC reports, around 3.3 to 3.6 billion people are highly vulnerable to climate change. Although no part of the world is invulnerable, countries and communities who have contributed the least to climate change are often being hit the hardest.   

In addition, the drivers of climate change, such as the burning of fossil fuels, are contributing to millions of premature deaths annually from air pollution.  

To address the health challenges of a changing planet, action must be taken at all levels – global, national, local and individual. WHO has set out a list of recommended actions for governments, businesses, mayors and health workers, and initiatives like Take The Jump are showing what individuals can do to make a difference.  

Academic institutions also play an important role. Scientific research is vital to improving our understanding, not only of the health impacts of climate change, but also the potential health benefits of climate action. Research can also show the specific measures that can be taken to help the world mitigate greenhouse gas emissions and adapt, as far as possible, to the worst consequences of climate change. 

LSHTM’s Centre on Climate Change and Planetary Health, including the affiliated WHO collaborating Centre on Climate Change, Health and Sustainable Development, focuses on six key shifts that we believe are needed to effect change at the speed and scale required to address intersecting climate and health crises. These changes can help to bring about a new era in public health with climate change at its heart.  

1. From hierarchies to healthy networks – we need to build collaborative networks that draw on expertise from different sectors, disciplines and geographies.  

2. From rapid response to ‘predict, prevent, prepare’ – our work modelling the changing threat from malaria and dengue in a warming world shows how research can help predict the trajectory of emerging health threats under different scenarios and inform interventions to help the world prepare. 

3. From separate specialisms to integrated expertise – we need to move from individual specialisms to international, cross-disciplinary efforts. We are collaborating with partners globally to study the health impacts of climate change, from heat-related deaths due to human-induced global warming and excess deaths caused by wildfire pollution, to the dangers of specific components of air pollution.  

4. From ‘winner takes all’ to multiple benefits of action – improved understanding of the health co-benefits of climate actions, such as transitioning to predominantly plant-based diets and decarbonising cities, should incentivise behaviour change and spur action to create societies that prioritise well-being, equity and ecological sustainability. 

5. From top-down to frontline-first – we need to address systemic inequalities by listening to those on the front-lines of climate change, such as pregnant farmers in West Africa who are working in extreme temperatures.    

6. From straight lines to big leaps – we need bold actions to achieve net-zero emissions by 2050 at the latest and enable the world to adapt to changes already taking place. Our work aims to generate the scientific evidence needed to inform these actions and provide tools that can help accelerate progress.  

Science may not be able to provide all the answers, but we know enough to take concrete actions now to build a healthier, more sustainable tomorrow. Evaluating the effectiveness of these actions in achieving deep cuts in greenhouse gas emissions and improvements in health will be essential to ensure that they have the intended impact.