Net-zero policies will bring major health and economic benefits

In addition to being essential for limiting global warming, measures aimed at achieving net zero are also public health policies, according to a new study published in The Lancet Planetary Health. 

Phasing out fossil fuel combustion and transitioning to clean, renewable energy sources; promoting low-carbon transportation options, such as cycling and walking, alongside public transport; and shifting towards healthier, more sustainable diets with less red and processed meat, could reduce millions of premature deaths annually from air pollution, unhealthy diets, and physical inactivity, while contributing to greenhouse gas emissions reductions. 

The study, led by researchers at the Institut de Biologie de l'Ecole Normale Superieure-PSL (IBENS), the Conservatoire national des arts et métiers (Cnam, Paris), and INSERM, in collaboration with researchers from the Pathfinder Initiative research team at the London School of Hygiene & Tropical Medicine (LSHTM), provides further compelling evidence on the major benefits that effective climate policies can bring to health and economies globally. 

While the concept of aligning climate and health goals, often referred to as the health co-benefits of climate policies, is well recognised in IPCC reports, the magnitude of potential health gains remains uncertain. 

Aiming to address this gap, the study reviewed and analysed scientific publications that modelled the health co-benefits of climate policies aligned with the Paris Agreement target of limiting warming to 2°C, or ideally 1.5°C. After assessing more than 2,500 studies, 58 studies were included in the review, covering the potential effects of 125 net-zero scenarios. The review encompassed global, multinational, national and sub-national studies, including assessments focusing on north-east Asia, Europe, India, China and the USA.  

The analysis showed that 98% of scenarios could bring substantial health benefits through air quality, physical activity and dietary changes, the three main pathways to health from climate mitigation. Half of the scenarios projected that mortality would be reduced by more than 1.5% through the health co-benefits of climate policies (corresponding to 234 life-years gained per 100,000 of the population per year).  

11 out of 13 studies (around 85%) found that economic benefits arising from health impacts of net-zero policies outweighed the cost of implementation, with the other two studies finding a partial compensation or net benefit depending on the country.   

Dr Kévin Jean, Junior Professor in Health and Global Change at the Institut de Biologie de l’ENS-PSL (IBENS) and coordinator of the study, said: “The latest IPCC report tells us that the costs of climate action are far lower than the costs of inaction. When we factor health into the equation, we see that the benefits of action outweigh the costs.” Dr Jean added that these social health costs include both monetary and non-monetary factors, such as lost well-being and harm to loved ones. 

The review also highlights that the health benefits of climate mitigation policies are often experienced locally in the countries and communities where actions are implemented, and are largely independent of actions in other countries and regions. This is in contrast to climate benefits which are dependent on coordinated global action and are distributed across the global population. 

Commenting on the significance of these findings, Dr Jean said: “When we talk about the health co-benefits of climate action, the argument that making efforts in France are pointless because it only accounts for 1% of global emissions becomes irrelevant.”

Dr Léo Moutet, PhD candidate at the MESuRS laboratory (Cnam) and the study’s lead author, said: “Until now, we had many reasons to believe that carbon neutrality policies were generally beneficial for health, but we didn't know to what extent.” 

As the study focused on the health co-benefits of climate policies, which are additional to the health benefits of reducing climate impacts, Laura Temime, Director of the MESuRS laboratory (Cnam), said: “If we also take into account the health benefits of mitigating direct climate impacts such as heatwaves or extreme rainfall, the health benefits of net-zero policies are likely much greater.” 

Professor Rosemary Green, Professor of Environment, Food and Health at LSHTM, said: “This study provides yet more evidence of the major health benefits that can be achieved in the near-term through policies to reduce greenhouse gas emissions. The findings strengthen the health and economic argument for ambitious climate mitigation action in countries like the UK.”

This review opens up several avenues for further research. In particular, the diversity of the studies analysed in terms of methods, mechanisms considered, and decarbonisation scenarios, underscores the need for a unified framework for assessing the health impacts of climate policies. Dr Jean said: "Without such a framework, we cannot compare different options for moving towards net-zero societies and thus identify the most favourable options for public health."

The study follows the publication of the report of the Lancet Pathfinder Commission in November 2023, which explored the health co-benefits of climate mitigation actions and highlighted major opportunities for greenhouse gas emissions reductions and health across sectors. 

This article was adapted from the original press release in French published on the ENS PSL website.