Following the Paris Agreement, we aim to quantify the impacts on weather-related risks corresponding to 1.5oC and 2oC of warming relative to pre-industrial conditions. We provide a set of bias corrected climate model output to be used in impact models. Our super-ensemble allows the quantification of relative risks of high-impact, low-probability events under present-day and 1.5oC and 2oC worlds, conditioned on a specific instance of internal climate variability, maximizing signal-to-noise.

What are relevant impacts that could be studied under a super-ensemble experiment?

We have a focus on extreme events and below gives an outline of the analysis that the HAPPI collaborators will perform with this data. We welcome further collaborations, and further analyses of our data.


  1. Comparison of methodologies between HAPPI, CMIP and pattern scaling. Lead: open, Contributors: all.
  2. Extreme meteorology: Heat, precipitation and wind related risks. Lead: open, Contributors: Oxford, CICERO.
  3. Food security: The impact on all levels of food security. Lead: open, Contributors: University of Reading.
  4. Mid-latitude dynamical changes: Changing in frequency and duration of blocking, storm tracks, jet variability, Rossby wave propagation. Lead: University of Bergen, MET Norway, Contributors: Oxford.
  5. Health impacts relating to extreme hot or cold spells and infectious diseases. Lead: Dr Mitchell, Contributors: London School of Hygiene and Tropical Medicine, PHE, UCL, Imperial College London, CDC.
  6. Flood risks changes, including droughts. Lead: Bristol University, Chinese Academy of Sciences, University of Tokyo, Contributors: ICBA.
  7. Economic impacts from, e.g. flood damage. Lead: open, Contributors: James Rising.
  8. Crop yield changes, specially in developing nations. Lead: ICBA, Reading University. Contributors: open.
  9. Projected climatic extremes and sustainable development pathways. Lead: Frank Sperling, Contributors: BAS.
  10. Changed extreme frequency on terrestrial carbon cycle. Lead: CEH, Contributors: open.
  11. Hurricane frequency and location changes. Lead: open, Contributors: LBNL, MIT.
  12. Open suggestions for other impacts