Report of the
Lancet Countdown
The latest Lancet Countdown report underscores the imperative for a health-centred response in a world facing irreversible harms.
Climate inaction is costing lives and livelihoods today, with new global projections revealing the grave and mounting threat to health of further delayed action on climate change. But bold climate action could offer a lifeline for health.
Our 2023 Report tracks the relationship between health and climate change across five key domains and 47 indicators, providing the most up-to-date assessment of the links between health and climate change.
Explore key findings of this year’s report
The Imperative for a Health-Centred Response in a World Facing Irreversible Harms
HEALTH HAZARDS, EXPOSURES, AND IMPACTS
A changing climate has profound implications for human health, with more frequent heat waves and extreme weather events, changing patterns of infectious disease transmission, deterioration of food and water resources, impacts on socioeconomic conditions, and the exacerbation of existing health challenges around the world. Indicators in this section track the multiple ways in which climate change threatens human health and wellbeing.
1.1.5 Heat-related mortality
In 2018-2022, people experienced on average 86 days of health-threatening high temperatures annually. 60% of such temperatures were made more than twice as likely to occur by human-caused climate change.
1.3.1 Dengue
The transmission potential for dengue by Aedes aegypti and albopictus increased by 42.7% and 39.5% respectively.
1.4 Food security and undernutrition
The higher frequency of heatwave days and drought months in 2021 compared to 1981-2010, is associated with 127 million more people experiencing moderate or severe food insecurity.
ADAPTATION, PLANNING, AND RESILIENCE FOR HEALTH
With climate change increasingly threatening the health and wellbeing of populations in every country, actions to build resilience and adapt to climate change are urgently needed. This section tracks how communities, health systems, and governments are understanding the health risks of climate change, the strategies and resources they are deploying, and how adaptation and resilience measures are being implemented globally.
2.1.3 City-level climate change risk assessment
In 2022, 94% of cities (848/898) reported they had completed or were undertaking a city-level climate change risk assessment, up from 713 in 2021.
2.2.2 Air conditioning benefits and harms
In 2021, air conditioning provided cooling in a third of households, but consumed about 1900 terawatt hours (TWh) of electricity (approximately the total electricity consumption of India and Brazil combined).
2.3.1 Vulnerability to mosquito-borne disease
Low HDI countries experienced a 37% decrease in vulnerability to Aedes-borne disease between 1990 and 2021, partly due to improvements in access to healthcare.
MITIGATION ACTIONS AND HEALTH CO-BENEFITS
Reducing greenhouse gas emissions is essential to limit the health threats of climate change. Simultaneously, many of the interventions required to mitigate and adapt bring enormous benefits for human health and wellbeing in the form of cleaner air, healthier diets, and more liveable cities. Tackling climate change could be the greatest global health opportunity of the 21st century. Indicators in this section track the world’s efforts to mitigate climate change, and the effective and the health benefits of this response.
3.2.1 Mortality from ambient air pollution
Global deaths attributable to fossil fuel-derived PM2.5 decreased from 1.4 million in 2005 to 1.2 million in 2020. Reduced coal pollution contributed to about 80% of the decrease.
3.2.2 Household air pollution
The use of polluting fuels resulted in 140 deaths per 100,000 associated with household air pollution in 2020 in 62 countries reviewed, 56% of which was due to the use of solid fuels.
3.3.2 Diet and health co-benefits
In 2020, 7.8 million deaths were associated with insufficient consumption of nutritious plant-based foods, and 1.9 million to excessive consumption of dairy, red and processed meat.
ECONOMICS AND FINANCE
The health impacts of climate change have profound economic implications. This section tracks the economic costs of the health impacts of climate change and its drivers, as well as the extent to which the world’s economy and financial systems are enabling the transition to a health-promoting, zero-carbon economy.
4.1.1 Economic losses due to weather-related extreme events
Global economic losses due to weather-related extreme events were US$264 billion in 2022. While 57.1% of losses in very high HDI countries were insured, 92.8% of losses in other countries were uninsured.
4.2.6 Compatibility of fossil fuel company strategies with the Paris Agreement
The strategies of the 20 largest oil and gas companies as of February 2023 would lead to production exceeding levels consistent with 1.5°C of heating by 173% in 2040, an increase from 112% expected as from February 2022.
4.2.7 Fossil fuel and green bank lending
Green sector lending has risen sharply since 2016, to US$498 billion in 2021, and is approaching fossil fuel lending. However, 22 of the top 40 private banks have increased their fossil fuel lending.
PUBLIC AND POLITICAL ENGAGEMENT
Public and political engagement underpins the foundations of the world’s collective response to climate change, with reductions in global emissions at the speed required by the Paris Agreement depending on engagement from all sectors of society. This working group tracks key actors’ engagement with the links between health and climate change, including in the media, national governments, the corporate sector, and the broader public.The indicators in this section track the links between health and climate change in the media, national governments, the corporate sector, and the broader public.
5.3.2 Scientific engagement on the health impacts of climate change
There are global inequalities in the location of studies referring to the health impacts of human-influenced climate drivers: 6.89 studies per million people in very high HDI countries, and 1.61 and 1.51, respectively, for medium and low HDI countries.
5.4.2 Engagement by international organisations
Tweets mentioning the health co-benefits of climate change action reached a record of 22% of all monthly tweets from International Organisations in November 2022, in a continuously upward trend.
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