Issue 600: A new modelling study highlights the health co-benefits of actions towards achieving the UK’s 2050 net zero targets.
Reduced indoor and outdoor air pollution, reduced consumption of meat and dairy, plus greater uptake of cycling and walking, could prevent 2 million premature deaths by 2050. The EU has committed to becoming a net zero economy by 2050, and under the EU climate law, Member States must cut emissions by at least 55% by 2030 – a commitment that is at the heart of the European Green Deal. The UK has also committed to a net reduction in greenhouse gas (GHG) emissions of more than 68% by 2030, compared with 1990 levels, and is aiming for net zero emissions by 2050. To achieve these objectives, reductions must be realised in electricity generation, transport and home energy, and consumers must make more sustainable choices in diet and travel, for example reducing meat consumption and choosing walking and cycling over vehicle use.
Since there are health benefits from these behaviours and reduced exposure to air pollution, researchers looked to quantify the impacts of different policy actions on health in England and Wales. Although the study is UK-based, the method could be adapted for EU countries, where findings are likely to be similar.
Paradoxically, they note that some actions that reduce emissions have as well a potential for negative health consequences, such as reduced ventilation in homes, greater risk of road injury through cycling, and possible negative effects from more plant-based diets. These potential negative consequences need now to be put in balance with the positive ones. Policies which maximise benefits and avoid unintended consequences must therefore be carefully designed, however most existing analyses looks at the health effects of actions in single sectors, e.g. energy or housing. In this study, the researchers therefore carried out multisectoral modelling to offer evidence of the combined effects on health of climate change mitigation policies in energy, transport, housing and food.
With modelling drawing on the risk factors given in the Global Burden of Disease1 study and other evidence, they quantified the impacts on mortality of six policy actions: switching to low-emission transport fuels; switching to low-emission home-energy fuels; increased home-energy efficiency; increased active travel; and reduced red-meat consumption with plant-based replacement. These actions were translated into health-relevant exposures and behaviours, for example exposure to fine particulate matter, based on available evidence. The researchers acknowledge some uncertainty in these averaged translations and assumptions: for example, the effects of weather and levels of indoor ventilation on air pollution. Average diets were taken from the National Diet and Nutrition Survey and reconfigured proportionally to reflect possible changes as red meat and dairy are replaced.
The impact of each policy action on mortality was quantified using a life expectancy table produced by the Institute of Occupational Medicine (the IOMLIFET model2), in combination with population and mortality data from the Office for National Statistics. Only mortality was modelled, but the researchers note that mitigation actions would also reduce ill health. The researchers compared the effects on health under two pathways – the UK Climate Change Committee’s Balanced Pathway of technological and behavioural measures, and the Widespread Engagement Pathway, which assumes more substantial changes to consumer behaviour. Both pathways share similarities in their decarbonisation strategies and trajectories, for example phasing out gas by 2035 and internal combustion engines by 2050.
Under the Balanced Pathway, mean PM2.5 concentrations are down by 27% by 2050 (relative to 2020 levels), and about 16% of emissions reductions would come from changes in consumer behaviour alone (e.g. through a 35% reduction in meat and dairy consumption). Under the Widespread Engagement Pathway, consumption of meat and dairy products is reduced by 50% by 2050, and up to a third of car journeys are replaced by walking, cycling or public transport (compared with 17% in the Balanced Pathway). This leads to 19% of emissions reductions through behaviour change alone. This pathway achieves a slightly greater reduction in outdoor fine particulate matter (PM2.5) air pollution, of 33% compared to the baseline scenario.
Combined actions under the Balanced Pathway result in more than 2 million cumulative life-years gained over 2021-2050. The estimated gain under the Widespread Engagement Pathway, meanwhile, corresponds to nearly 2.5 million years of life by 2050. Under both, the greatest contribution to health improvement is from home energy efficiency, which adds more than 800 000 life-years by 2050, due to fewer winter deaths and decreased indoor-generated air pollutants (assuming good ventilation). Interestingly, replacing domestic gas and biofuels with electricity and hydrogen has an even greater impact on PM2.5 concentrations than changes to road traffic fuels and coal-fuelled electricity, because domestic combustion accounts for a greater proportion of the UK’s PM2.5 emissions. Actions leading to net zero will likely confer substantial benefits for public health, with greater, faster benefits achieved through the more ambitious pathway. The researchers highlight that people might be willing to undertake more radical increases in active travel, motivated by health benefits. Although interventions to change behaviour are challenging, this study clearly indicates the health gains of ambitious targets.
Footnotes:
- GBD 2019 Risk Factors Collaborators (2020) Global burden of 87 risk factors in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019. Lancet. 396: 1223-1249.
- Miller. B.G. & Hurley, J.F. (2003) Life table methods for quantitative impact assessments in chronic mortality. Journal of Epidemiol Community Health. 57: 200-206.
Source:
Milner, J., Turner, G., Ibbetson, A., Colombo, P.E., Green, R., Dangour, A.D., Haines, A. and Wilkinson, P. (2023) Impact on mortality of pathways to net zero greenhouse gas emissions in England and Wales: a multisectoral modelling study. The Lancet Planetary Health, 7(2): e128-e136. https://doi.org/10.1016/S2542-5196(22)00310-2
To cite this article/service:
“Science for Environment Policy”: European Commission DG Environment News Alert Service, edited by the Science Communication Unit, The University of the West of England, Bristol.
Notes on content:
The contents and views included in Science for Environment Policy are based on independent, peer reviewed research and do not necessarily reflect the position of the European Commission. Please note that this article is a summary of only one study. Other studies may come to other conclusions.
Source: European Commission | Environment (https://bit.ly/43dYjDa)