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 publishes annual updates of 41 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 120 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

The collaboration began its work with a public consultation, seeking to identify which areas of health and climate change could and should be tracked. Every year since, this suite of indicator has been expanded and improved, and 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 globe trends to be observed at a global level.
  • Be updatable periodically, ideally annually.

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 kept up to date, ideally allowing for annual updating of the indicator.

If you are interested in contributing to our research or helping to develop new indicators, please contact us at info@lancetcountdown.org

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.

Need all the detail? Download the Report