Our Science

To deliver the best-available science the Lancet Countdown has developed an open, transparent, and rigorous process for the development and improvement of its indicators, data and methods. Read more about this process below.

The Lancet Countdown: Tracking Progress on Health and Climate Change

The Lancet Countdown publishes annual updates of over 40 indicators developed by our experts across five key areas:

  1. The health impacts, exposures and vulnerabilities of climate change
  2. Adaptation, planning and resilience for health
  3. Mitigation actions and their health co-benefits
  4. Economic and financial aspects of the interaction between climate change and health
  5. Public and political engagement in climate change and health

To track these five key areas we draw on over 200 world-class experts from a range of disciplines, including health and epidemiology, climate science, engineering, agriculture, transports, economy, and social and political sciences.

Our Indicators

Our indicators span a range of disciplines and expertise. Each indicator in the Lancet Countdown’s assessment must:

  • Track an aspect of the relationship between health and climate change, well evidenced in the literature and not adequately covered through other indicators in the report.
  • Utilise data from a reliable source, available at adequate temporal and spatial scales to enable trends to be observed at a global level.
  • Be updatable periodically, ideally annually or more regularly.

The indicators must also be:

  • Meaningful: Track an aspect of the relationship between health and climate change that is well evidenced in the literature, and relevant at a global level
  • Relevant: The area being tracked by the indicator must be of relevance to policy and decision makers, and/or represent an important contribution to the field of science of climate change and health
  • Scientifically sound and reproducible: The indicator must use a well-established, internationally accepted, and ideally previously published scientific methods
  • Temporally representative: The indicator should provide annual data for the recent past and to a year as recent as possible. It must be available across an adequate timescale to allow for attribution to climate change, where relevant
  • Geographically representative: The indicator should be ideally available at a country, or higher level of resolution. Its geographical coverage should be enough for global trends to be observed, covering at least 40 countries evenly distributed across the four World Bank income contexts, the four Human Development Index Groups, and the five WHO regions initially, with possibility of expansion to 150 countries at least. In the case of indicators tracking aspects relevant to restricted locations, over 80% of relevant countries must be covered by the indicator
  • Reliable and use updatable sources: The indicator should use data from a reliable source, fit for its purpose. Publicly available databases, and especially those developed by international organisations, governmental bodies or academic institutions, are preferred. Data sources must be regularly updated.

Strengthening Our Indicators

We are committed to continuously improving our indicators, ensuring we deploy the best-available science to track progress on health and climate change across the world. The Lancet Countdown’s report goes through two tiers of strict assessment processes:


  1. The Indicator Quality Improvement Process:
    All new indicators undergo a thorough quality check and improvement process before being considered for the annual assessment. In this process, independent experts assess the quality and suitability of the indicator and provide constructive feedback to aid their development and improvement.
  2. The Lancet’s Peer Review Process:
    Each year, our report is published in The Lancet, one of the world’s highest impact general medical journals. Before publication, our report is stringently edited and peer-reviewed, to ensure its excellence and medical relevance.

Get involved

The Lancet Countdown is an open, collaborative research programme. We are committed to continuously improving our work, and ensuring our outputs reflect the best available science. We believe that the most relevant science is that which is driven by local researchers, familiar with their local context. To this end, we maintain an open approach, welcoming engagement with new academic partners globally with the expertise and capacity to make substantial contributions to our indicators, and other academic outputs. We invite direct input on the content, methods, and data of our current indicators and indicator domains.

If you would like to contribute to the Lancet Countdown’s annual indicator reports, either by developing new indicators, helping improve existing ones, or contributing to other academic work, please contact us at  info@lancetcountdown.org.  We particularly encourage and favour contributions of colleagues from low- and middle- Human Development Index (HDI) countries. We actively encourage input from minority ethnic candidates and disabled candidates who are currently underrepresented in academic research and institutions.

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