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COP26: Considering the negative health effects of climate change

Ahead of the COP26 climate summit in late October, researchers are calling for political leaders to consider the negative health effects of climate change. According to Sir Andrew Haines, “Climate change is projected to have far-reaching and potentially catastrophic effects on health.”

Ylva Rylander / Published on 4 October 2021
Two young Malian girls drinking water straight from a tap, Mali

Two young Malian girls drinking water straight from a tap, Mali. Photo: Riccardo Lennart Niels Mayer / iStock / Getty Images.

Sir Andrew Haines is one of the world’s leading experts on climate and health and calls for concerted action from scientists, policymakers and practitioners to minimize the impact.

“A conversion to fossil-free societies can have major and positive effects on public health in the short term. And redesigning our cities so that walking, cycling and public transport become more attractive, it will bring major health benefits through increased physical activity,” said Prof. Haines at this year’s Gordon Goodman Memorial Lecture.

Climate change and health – a crucial topic

The 2021 Gordon Goodman Memorial Lecture focused on a crucial topic: the direct and indirect ways in which climate change impacts human health and solutions that can yield multiple co-benefits for people and the environment.

“We have a fantastic keynote speaker this year and we are proud to co-host this memorial lecture together with the Royal Swedish Academy of Sciences and Stockholm University,” said SEI Deputy Director Åsa Persson in her welcome remarks.

“This year’s topic feels incredibly important and urgent. We have felt the health impacts from a large, looming global threat, the pandemic,” she added.

Climate change is an existential threat. To respond to this threat and also find solutions that improve quality of life, we at SEI are looking particularly at health and climate co-benefits from tackling air pollution and how we can include those in national climate plans.

Åsa Persson, Deputy Director, SEI

“The effects on human health may be direct – from extreme heat; mediated through ecosystems, such as changes in the incidence and distribution of vector-borne diseases, including dengue and malaria; or mediated through complex socioeconomic pathways such as impoverishment and population displacement,” wrote Prof. Haines in the abstract of this year’s lecture.

Disruptions to ecosystems, such as allergies, asthma and food-water and insect-borne illnesses, and societal systems, malnutrition, work capacity, conflict and mental health illnesses will push more people into poverty. In addition, they not only affects physical health, but also psychological well-being.

Haines also mentioned that the threat of climate change can lead to mental health issues, including amongst the young, who are considering not having children due to fear of the future.

“There is evidence that climate change is already having effects on our health,” said Prof. Haines. He noted that declines in the production of vegetables, legumes and fruits may increase the risks of non-communicable diseases such as cardiovascular diseases, diabetes or cancer.

Mitigation and adaptation to climate change

One way is to adapt to climate change and we can adapt to a certain point. However, we also need to mitigate. Integrating adaptation and mitigation as far as possible is also required.

“Required actions are lagging behind,” said Prof. Haines.

Implementing policies to promote resilient health systems, able to respond to climate shocks can reduce health effects. However, cutting emissions rapidly to achieve the target of the Paris Agreement, to limit the global average temperature increase to well under 2°C, will be essential to reduce the risks to health.

Sir Andrew Haines, Professor of Environmental Change and Public Health at the London School of Hygiene and Tropical Medicine

Watch the Gordon Goodman Memorial Lecture

Health argument for climate action

Dr Maria Neira, Director of Public Health and the Environment Department at the World Health Organization, commented on Prof. Haines’ lecture.

“The first imbalance is about the sources of emissions versus those who will suffer the impact,” she said. “I think this inequity factor, that vulnerable people will suffer the most, is fundamental and needs to be addressed. So I hope we will be able to moderate this and accelerate action.”

Dr Neira added that the role of public health professionals is changing. Apart from providing medical expertise, their responsibilities also include influencing the energy sector and convincing different actors to stop using fossil fuels.

We need to all be prepared for this new role and stop using fossil fuels that are bad for our health. At COP26 in Glasgow, we hope to present a report on the health argument for climate action. We will focus on the lungs of the people. If we tackle the consequences of climate change correctly, this will generate enormous public health benefits."

Dr Maria Neira, World Health Organization

Healthy diets from sustainable food systems

Increased carbon dioxide in the atmosphere is reducing nutrients in crops. Around 2 billion people currently suffer from micronutrient deficiency, which impacts human health. Drought can result from water shortages, migration and displacement, resulting in challenges to mental health and other effects that can have complex and far-reaching effects on human health.

“It’s a rather worrying picture “but there are solutions,” said Prof. Haines.


 The EAT-Lancet Commission 

The EAT-Lancet Commission on healthy diets from sustainable food systems estimates that planetary health diet and targets for sustainable food production can prevent 11 million premature adult deaths per year and lead to a sustainable global food system by 2050.




Generating evidence for action

Prof. Haines divided possible solutions into two broad categories:

I. Scientific discovery

  • Transdisciplinary understanding of complex causes of changes in health with multiple concurrent environmental stressors
  • Assessment of tipping points, beyond which sudden state shifts may occur, posing risks to health.

II. Enabling action

  • Facilitation of early warning of impending threats to human health
  • Evaluation of the effects of adaptation and mitigation actions on health
  • Overview of progress towards nationally and internationally agreed targets
  • Enhancement of transparency and accountability.

Prof. Haines also mentioned several other solutions:

  • Nature-based solutions are important and can provide over one-third of the cost-effective climate mitigation activities needed between now and 2030 to stabilize warming below 2°C, according to an article published in PNAS 2017.
  • Modelled dietary change
  • Reducing carbon emissions from healthcare. The National Health Service in England has committed to net-zero by 2040 for direct emissions and 2045 for indirect emissions.
  • Optimizing biomass use for health
  • Forest conversation reduces disease risks in the Brazilian Amazon
  • Sustainable cooling strategies.

Climate-related factors that will impact our health

The question “What is the most important climate-related factor that will impact our health?” was posed to the audience after the lecture. According to 68 respondents from the audience, the results shows that “food security” and “access to drinking water” were the two most important climate-related factors that will impact human health.

Audience response 2021

Results from Mentimeter poll at Gordon Goodman Memorial Lecture, 15 September 2021.

A climate-friendly recovery from Covid-19

Prof. Haines also mentioned a recent poll showing that most people support a “climate-friendly” recovery from Covid-19, ranging from 80% in China, India and Mexico to 57% in Australia, Germany and the US.

SEI team and partners

Åsa Persson
Åsa Persson

Research Director and Deputy Director

SEI Headquarters

Johan C.I. Kuylenstierna

Reader / Research Leader

SEI York

Ylva Rylander
Ylva Rylander

Communications and Impact Officer


SEI Headquarters

Per Larsson, Communications Officer, Stockholm University
Peter Brandén, Programme Coordinator, The Swedish Royal Academy of Sciences

About Sir Andy Haines and the organizers of this event

Sir Andy Haines is Professor of Environmental Change and Public Health at the London School of Hygiene and Tropical Medicine. His most recent book “Planetary Health: Safeguarding Human Health and the Environment in the Anthropocene”, was published in July 2021 by Cambridge University Press.

Welcome remarks were given by Åsa Persson, Deputy Director of SEI, Dan Larhammar, President of the Royal Swedish Academy of Sciences, and Astrid Söderbergh Widding, President of Stockholm University. Anders Nordström, Ambassador for Global Health at the Ministry for Foreign Affairs of Sweden, moderated the panel discussion with five international scientists and policy experts.

The Royal Swedish Academy of Sciences, SEI and Stockholm University organized the Gordon Goodman Memorial Lecture given by Professor Sir Andy Haines on 15 September 2021.

Twitter: @SEIresearch @SEIclimate @Stockholm_Uni @vetenskapsakad
Hashtags: #GGLecture | #ClimateChange | #HumanHealth

About the Gordon Goodman Memorial Lecture

The Gordon Goodman Memorial Lecture is held annually in honour of Gordon Goodman, founding director of the Beijer Institute at the Royal Swedish Academy of Sciences (1977–1989) and the Stockholm Environment Institute (1989–1991).

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