The KeyCLIM project

There is overwhelming evidence that the North Atlantic, Arctic Ocean and surrounding land masses together form a key region for understanding northern latitude climate. Rapid climate change in this region is both a study opportunity and study obligation. Already now and even more so in the coming years significant changes are expected to be felt in weather patterns, biosphere and cryosphere and hence Norwegian and other northern societies (IPCC, 2013). How exactly will these changes look like? Do we have sufficient understanding of the Earth system to attribute trends in precipitation, extreme precipitation, glacier melt, ocean circulation, sea ice extent to climate change and associated forcing and feedback mechanisms? Which components of Earth System Models (ESMs) require further development because they represent key uncertainties in climate projections? Will feedback processes and the coupling between the spheres result in large or even irreversible shifts to the Earth system? Can we use ESMs efficiently to help answering questions on attribution, mitigation strategy and climate adaptation?

In KeyCLIM, the core team of modelers and institutions developing the Norwegian Earth System Model (NorESM) will assess its performance, develop it further and evaluate important physical processes. Ultimately KeyCLIM shall achieve a much improved picture of the near and long term future climate for the Arctic, northern latitudes and Norway, providing open data to the climate mitigation and climate impact community. 

The primary objective of the project is:

  • to use a nationally coordinated Earth system approach to understand, quantify and reduce uncertainty in projected northern latitude climate change and in particular Arctic warming.

The secondary objectives are:

  • Significantly advance the understanding of Earth system forcings, feedbacks, circulation and hydrological cycle in a warming Arctic and North Atlantic region through advanced data and model analysis.

  • Enhance the Norwegian Earth system modelling capability to address future scenarios of climate change through activating additional climate system components, improving the representation of key processes and increasing model resolution.

  • Quantify with improved modelling capability and systematic model experiments the likelihood of major or irreversible climate change in northern latitudes.



Results from Earth System Models (ESMs) participating in the 6th phase of the Coupled Model Intercomparison Project (CMIP6) showing near-surface temperature change. Left: temperature change averaged over the globe and the year. Lines show the mean, and shading shows the spread of the historical period and 4 future projections predictions by an ensemble of 23 ESMs. The anomalies are taken with years 1850–1879 as a baseline. Results for historical runs (1850-2014) are presented in blue. Orange, red, purple, and brown colors present results based on best-case to worst-case scenarios for the future. Please note the different range Right: Projected near-surface (2m) temperature change for the season December-January-February, over the years (2071 - 2100) – (2015 - 2044) and under the future forcing scenario SSP-3.70. Figure by A. Gjermundsen.

Access KeyCLIM data 

In KeyCLIM, WP6 coordinates a set of sensitivity simulations based on the key processes identified in WPs 3-5. Data from these experiments is currently available for NIRD users that are members of the NIRD storage project NS9252K. 

Read more about how to access data from the KeyCLIM sensitivity experiments here .

Below is a list of potential processes to be considered in WP6 sensitivity experiments.


KeyCLIM coordinated sensitivity experiments
No.  Sensitivity experiment Component modifications
1. Interactive ozone + VSLS tracer Atmospheric chemistry and Ocean biogeochemistry
2. Atmospheric boundary layer Atmospheric physics
3. Oceanic boundary layer Ocean physics and biogeochemistry
4. Eddy parameterization Ocean physics
5. Land ice sheet coupling Ice sheet and land
6. Ice formation in clouds Cloud microphysics
7. Snow dynamic over sea ice Sea ice
8. All changes combined Atmospheric chemistry, ocean biogeochemistry, atmospheric physics, ocean physics, ice sheet, land, cloud microphysics, sea ice