United Kingdom: reaching “net zero emission” could improve population health

17 February 2023

At the end of 2020, the United Kingdom committed to reducing its greenhouse gas emissions by over 68% by 2030 and aims to achieve “net zero emission” by 2050. Most evidence on the health impact of climate change mitigation measures is based on the assessment of unique sectors. To provide further evidence, a recent study has estimated the effects of policies covering four sectors on the health of the population. According to this work, the implementation of such measures would lead to significant health benefits for the population.

The Paris Agreement, signed in 2015 by 196 countries, commits nations to undertake ambitious efforts to tackle climate change. To assess the effectiveness of the government’s measures, the UK Climate Change Commission publishes an annual report on the UK’s carbon footprint. In 2020, the Commission’s sixth report recommended measures to reduce greenhouse gas emissions in four sectors: energy, transport, housing, and agriculture.

As noted in the existing literature, many of these measures would improve population health by encouraging health promoting behaviours. The recent study by Milner et al, 2023 assessed the integrated effects of six policies, proposed by the latest report of the Commission on Climate Change, should they be applied to the population of England and Wales.

Reaching zero net emission: 2 scenarios considered

All six policies analysed in this study are those assumed to have the greatest impact on population health (see table 1).

Policies Sectors Potential effect on health
Switching to low greenhouse gas emission electricity generation Energy Effect on exposure to ambient fine particulate matter
Switching to low-emission fuels for domestic energy consumption Housing
Improving energy efficiency in housing Housing
Switching to low-emission fuels for transport Transport
Increasing active travel (walking, cycling) Transport Effect on physical activity
Reducing red meat consumption and switching to plant-based foods Food and diet Effect on dietary composition and quality

Table 1: Policy actions to reduce greenhouse gas emissions in the selected sectors and their potential effects on health (from Milner, 2023)

Two different scenarios were proposed for the implementation of these measures and compared to a baseline scenario :

  • A “balanced” pathway, based on technology and energy-related actions, requiring modest changes in consumer behaviour.
  • “A widespread engagement” pathway involving more significant changes in consumer behaviour.

The more people are involved, the greater the health benefits

The widespread commitment scenario achieves a slightly greater reduction in outdoor air pollution (33%) from fine particulate matter than the balanced scenario. Home energy efficiency installations proceed at a more rapid rate under a widespread engagement pathway, resulting in a decrease in indoor exposure, and thus to an improvement of population health.

By 2050, one third of car trips would be replaced by active travel under the widespread engagement scenario, compared to 12% under the balanced scenario. The study estimates that the increase in active travel under a widespread engagement would thus be associated with health benefits 2 to 3 times greater than those of a balanced scenario.

Lastly, the widespread commitment would lead to a 50% reduction in meat and dairy consumption by 2050, compared to 35% for a balanced commitment. A greater reduction in the consumption of red meat would result in a higher consumption of fruit (17-18 g/day), vegetables (22-23 g/day) and legumes (5-7 g/day), and thus in an improvement in diet quality.

Combined policies could significantly reduce mortality by 2050

Beyond direct health benefits, combining all six policies would also substantially reduce mortality by 2050, with a greater reduction for the widespread scenario. 2.5 million years of life would be gained by 2050 in England and Wales (study area) under a widespread engagement, compared to 2 million in the balanced scenario. The number of life years gained through widespread pathway could reach 13.7 million by 2100.

While this study provides only broad estimates of the impact of climate change mitigation measures on health, inducing substantial changes in behaviour could lead to greater health benefits than targeting technology alone.

This study highlights the need to put health at the core of policies and underlines the urgency of addressing climate change.

Net zero emission for a sustainable climate

According to the Paris Agreement, limiting global warming to 1.5°C requires significant reduction greenhouse gas emissions and the achievement of “net zero emissions” (United Nations, 2022).

“Net zero emission” is defined as a situation in which human-induced greenhouse gas emissions are reduced to as near to zero as possible, with the remaining emissions being offset by the removal of an equivalent amount from the atmosphere (IPCC, 2018).

In its latest report, the IPCC has called on governments to significantly strengthen their contribution to this goal and to urgently take ambitious action to reduce greenhouse gas emissions (IPCC, 2022).