How does climate change threaten our health?

It is becoming increasingly well-recognised that climate breakdown presents a major and potentially devastating threat to health, both globally and in the UK.  As stated by the recent 2019 Lancet Countdown report (Watts et al., 2019), ‘The life of every child born today will be profoundly affected by climate change. Without accelerated intervention, this new era will come to define the health of people at every stage of their lives’

A stable climate underpins many key social and environmental determinants of health; from the capacity of the world’s ecosystems to provide clean water, air and nutritious food, to our access to shelter, infrastructure and services.

  • Significantly increased physical and mental ill health and mortality are projected as a result of extreme weather events, disruption to food and water supplies, increased spread of infectious diseases and climate-related displacement and conflict.

  • Direct health impacts in the UK will arise from increased risks from heatwaves and flooding

  • However, the indirect health impacts could be even greater. Climate change will negatively affect international social, economic and political stability and cause rising food poverty through supply-chain disruption.

  • It will affect poor and marginalised groups most, thus increasing health inequalities.  In the UK this is expected to particularly affect our ageing population.

Background to the infographic

With growing public awareness of these concerns following media coverage of the youth climate strikes and Extinction Rebellion, this year large numbers of UK health professionals have mobilised and formed advocacy groups such as Doctors for Extinction Rebellion ( and Health Declares Climate Emergency (  Both are calling for issues relating to climate change and health to be front and centre in the 2019 election.

To help physicians and the public to better understand the commitments on the most health-relevant environmental policy areas that the main parties have made in their manifestos we produced this evidence-based infographic with the assistance of experts in climate change and environmental policy from Imperial College London (Dr. Iain Staffell and Dr. Oytun Babatunde).

All of the health  impacts detailed on p.2 will be much worse at 2⁰C or higher of warming than if warming is kept below 1.5⁰C (Ebi et al. 2018). In developing the graphic, we were cognisant of the fact that, despite the scale and increasing visibility of the threats posed to health by climate change, the UK currently lacks policies to match the level of mitigation and adaptation ambition required.  For example, the independent Committee on Climate Change (CCC, 2019) warns that current policies and plans are insufficient to meet the Fourth or Fifth Carbon Budgets (covering 2023 to 2032).

There is also growing evidence that the previous target of net zero emissions by 2050 (as adopted by the UK Parliament in June 2019) is inadequate to protect health and wellbeing.  This is because, firstly,  the world as a whole needs to achieve net zero before 2040 to keep warming below 1.5⁰C by 2100 (Walsh et al 2017), and secondly, that high-income countries such as the UK would have to decarbonise more rapidly than the global average rate on the grounds of equity.

Our methods

We developed an initial set of policy areas, selected to cover the largest potential health ‘co-benefits’ resulting from action on climate change, as well as those with the greatest scope for climate mitigation at the scale and pace required. These were refined to produce the following shortlist of 10 policy areas:

  1. Decarbonisation and investment in developing a zero-carbon economy
  2. A ban on fracking
  3. A commitment to reduce levels of air pollution to World Health Organisation (WHO) limits
  4. Development of more energy-efficient homes
  5. Transport: incentivise public and active transport
  6. Social justice & reducing health inequalities within action on climate change
  7. Public engagement & public education (on climate impacts and mitigation)
  8. An independent environmental public watchdog (e.g. an Office for Environmental Protection)
  9. Sustainable food and farming systems
  10. Programme of reforestation, ecosystem restoration and rewilding

We selected the final criteria for inclusion in the infographic as the highest ranked (see next page) from a survey of UK health professionals in the Health Declares Climate Emergency network

Scoring manifesto commitments

We extracted data from party manifestos and individually scored party manifestos on each criterion as 0 (no policy or policies that counter the aim), 0.5 (positive but incomplete policy) or 1 (comprehensive and evidence-based policy).  We then compared scores and associated manifesto quotes across parties in a group discussion and agreed consensus scores to produce this infographic (figure 1).

The column on the right shows the key considerations taken into account in scoring each criterion.

Policy areaKey considerations
Decarbonisation and investment in developing a zero-carbon economy– Speed of emissions reductions planned

– Amount to be invested in low-carbon economic transformation

– Scope: net zero commitments should include international aviation and shipping and exclude international emissions credits

– Commitment to phase out oil and gas subsidies

Cleaner air– Commitment to a Clean Air Act incorporating WHO standards

– Specific plans on how to achieve this

– Mechanisms to ensure accountability

Green homes– Ambition of proposed policy or programme (e.g. number of homes to be insulated per year, amount to be spent)
Transport: focus on incentivising active and public transport– Commitment to and proposed investment in increasing active travel (walking and cycling)

– Phase-out of diesel and petrol vehicles (CCC have recommended a sales ban on conventional vehicles moved to 2030-2035)

– Planned investment in local public transport

– Commitment to prevent airport expansion

Sustainable food and farming systems– Commitment to carbon labelling of food to help the public choose lower carbon foods.

– Promotion of diets lower in red and processed meat and/or a diet similar to the Planetary Health diet (Willet et al, 2019)

We extracted data from party manifestos for relevant commitments on each of these criteria and then, taking into account the considerations on page 5, individually scored party manifestos on each criterion as:

0 (no policy or policies that counter the aim),

0.5 (positive but incomplete policy) or

1 (comprehensive and evidence-based policy)

We compared scores and associated manifesto quotes supporting them across parties in a group discussion and agreed consensus scores to produce the infographic (page 1).

The final scores

 Political Parties (alphabetical order)
BrexitConservativeGreenLabourLib DemsSNPPlaid Cymru
Decarbonisation & zero-carbon investment00.511110.5
Clean air00.511100.5
Green homes00.51110.50.5
Food and Farming0010.50.500.5

What you can Do

Good health for our families, our patients and our communities depends on a stable climate and healthy ecosystems. The next Government’s policies must reflect these pressing concerns.

We are asking all health professionals to vote with climate change and health in mind on December 12th, using our scoreboard to help inform your decision.  Even more importantly, please encourage your colleagues and others within your sphere of influence to do so as well.


Watts N, Amann M, Arnell N, Ayeb-Karlsson S, Belesova K, Boykoff M, Byass P, Cai W, Campbell-Lendrum D, Capstick S, Chambers J. The 2019 report of The Lancet Countdown on health and climate change: ensuring that the health of a child born today is not defined by a changing climate. The Lancet. 2019 Nov 16;394(10211):1836-78.

Ebi K, Campbell-Lendrum D, Wyns A. The 1.5 Health Report. (Oct 2018). Online at

Committee on Climate Change (CCC) (2019) Summary Report: 2019 Progress Report to Parliament.

Walsh B, Ciais P, Janssens IA, Penuelas J, Riahi K, Rydzak F, Van Vuuren DP, Obersteiner M. Pathways for balancing CO2 emissions and sinks. Nature communications. 2017 Apr 13;8:14856.

Willett W, Rockström J, Loken B, Springmann M, Lang T, Vermeulen S, Garnett T, Tilman D, DeClerck F, Wood A, Jonell M. Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems. The Lancet. 2019 Feb 2;393(10170):447-92

Written and developed by:

Dr Yasaman Barzin, Dr Isobel Braithwaite, Dr Anya Göpfert, Dr Chris Newman, Dr Ruth Speare, Dr Sarah Gentry, Alexander Crane, Michael Baldwin, Dr Oytun Babacan (Imperial College London) and Dr Iain Staffell (Imperial College London)