What is a climate indicator?

Climate Indicators (CI) are:

  • Summaries of past and projected climate change, observed and projected  changes affecting nature and society;
  • Condensed climate information for climate impact assessment so users do not have to run the whole production chain;
  • Based on quantitative data derived from Essential Climate Variables (ECVs); gridded climate model data, reanalysis and/or observations;
  • Often using defined criteria by WMO’s Expert Teams on Climate Change Detection and Indices (ETCCDI), on Sector Specific indices (ET-SCI), and the Swedish Meteorological and Hydrological Institute ETCCDI ET-SCI, SMHI

The CI can describe global climate change, be used to trace climate hazards, assess sensitivity of ecosystems and society, and can help in raising awareness and informing climate change adaptation policies and actions. Different societal sectors have different adaptation challenges, and different CIs can be needed  in different sectors.

A Climate Indicator (CI) is an aggregate measure used to measure the climate change on complex environmental phenomena in terms of trends and variability.

View full list: CIs available in climateinformation.org. 

Climate Indicators are calculated from two well trusted and globally known climate scientific communities:

  • Global Climate Models (GCM) used in the Coupled Model Intercomparison project Phase 5 (CMIP5)
  • Coordinated Regional Downscaling experiment (CORDEX) Regional Climate Models

The climate indicators are calculated for different Representative Concentration Pathways (RCP), 2.6, 4.5, and 8.5.

To help make assessments for the future, indicators are provided for different time periods:

  • a reference period (1981-2010, absolute values)
  • early century (2011-2040, expected future change values)
  • mid-century (2041-2070, expected future change values)
  • end-century (2071-2100, expected future change values).