About CHEX

Climate Hazards and Extremes (CHEX) is a strategic project within the Bjerknes Centre for Climate Research’s (BCCR) research theme Climate Hazard. CHEX is an interdisciplinary project with 18 researchers from the University of BergenNORCE and the Nansen Environmental and Remote Sensing Center, with backgrounds in climate modeling, hydrological modeling, meteorology, and Quaternary geology.

Climate hazards is a theme of growing importance and draw interest not only from the scientific community but also from policy-makers, industrial and financial actors, as well as local governments. CHEX brings together the Bjerknes Centre for Climate Research’s expertise on climate-related geohazards, sea-level change, and extreme weather events, to conduct innovative research. The project aim to build long-lasting relations between climate researchers and decision-makers to increase society’s resilience to climate hazards.

The backbone of any impact and risk modeling approach is an in-depth knowledge of today’s climate, and its historical variability on relevant timescales, as long records of natural climate variability will help project current and future climate change. Past climate variability and knowledge of past extreme events are gathered from instrumental data records and historical sources. Further back in time, however, we have to rely on paleorecords, such as lake sediments, to give us information on climate variability. Linking proxy data from paleorecords with the instrumental data records is key, as this will enable integration of paleodata in numerical models for projecting future climate change and extreme events.


The main objective of the project is:

«To provide policy-relevant information through improved projections of climate hazards and extremes, by integrating long-term time series from proxy records with numerical model output and Earth observation data.»


The project has four work packages:

  • WP1: Science–Policy Bridging and Communication with Users
  • WP2: Storms and their hydrological impact
  • WP3: Sea-level rise, storm surges, and waves
  • WP4: New time series of past and present climate extremes


WP1: Science-Policy Briding and Communication with Users

Escalating loss from climate hazards is a global trend and is in part explained by an increase in extreme phenomena such as floods, storms, droughts and storm surges, as stated by the Intergovernmental Panel on Climate Change (IPCC). Most societies are ill-prepared for such shifts, and their major destructive and costly effects. There are several possible reasons for the lack of climate hazard resilience in different societies, such as lack of simple solutions, complex inter-dependencies, uncertainties at different levels of decisions making within the society, and the differing spatial and temporal scales of the impacts.

The aim of WP1 is to strengthen the existing, and forge new links between climate researchers and policy-makers. We aim to improve societal climate hazard resilience by providing information and insight on the effect of climate hazards and how current and future climate change affects these events. The work on establishing a lasting and trusting relationship between climate researchers and decision-makers have already been established through other initiatives at the BCCR, such as HordaKlim, HordaFlom and ExPrecFlood, in which we also will contribute.


WP2: Storms and their hydrological impact

The overall goal of WP2 is to improve the knowledge of the past, present and future hydrological cycle, hydrological change and hydrological variability at local and regional scales.

… More information TBA.


WP3: Sea-level rise, storm surges, and waves

Changes to mean sea level (MSL) and sea level extremes leads to changes in coastal impacts, and the society’s exposure and risk to such impacts. Extreme sea levels are a result of a combination of simultaneously occurring phenomena and are dominated by short-lived events such as storm surges. Although, in long-term coastal flooding projections, the MSL increase also becomes an important component. MSL changes are caused by large scale variability in both the atmosphere and in the ocean.

The main outcomes of WP3 is an assessment of the effect of large scale North Atlantic ocean-climate variability on the sea level along the European Atlantic Coastline, and assessment of the potential benefit for extreme value analysis by removing known long term MSL variability. The outcome will also include a review of methods for assessing future flood risks, applied in Norway, Sweden, Finland, Denmark, and Germany.


WP4: New time series of past and present climate extremes

Floods are among the most severe natural hazards, causing devastation both in terms of human suffering and economic cost in all corners of the world. River floods are often associated with intense rainstorms, or spring floods caused by rapidly melting snow in mountainous areas – often in combination with rain. Understanding the causes of individual flood events is often trivial, however, the question of how the frequency and severity of floods are linked to long-term climate variability and trends remains largely unanswered.

Unfortunately, direct measurements of rainfall, water runoff, and other flood-related variables are very limited, both in time and space. The aim of WP4 is to obtain such information from paleorecords, mainly lake sediments. Lakes trap all type of erosional products of up-valley cryosphere processes. The influx of these sediments can be analyzed and fingerprinted utilizing various lab-methods, which along a robust age-depth model yields flood records extending thousands of years into the past.