Precipitation extremes

Assessment versions

Published (reviewed and quality assured)

• Precipitation extremes (CLIM 004) - Assessment published Nov 2012

Justification for indicator selection

Changes in the frequency and intensity of extreme precipitation can have considerable impacts on society, including the built environment, agriculture, industry and ecosystem services. An assessment of past trends and future projections of extreme precipitation is therefore essential for advising policy decisions on mitigation and adaptation to climate change. The risks posed by precipitation-related hazards, such as flooding events (including flash floods) and landslides, are also influenced by non-climatic factors, such as population density, floodplain development and land-use change. Hence, estimates of future changes in such risks need to consider changes in both climatic and non-climatic factors. Estimates of trends in heavy or extreme precipitation are more uncertain than trends in mean precipitation because, by their very nature, extreme precipitation events have a low frequency of occurrence. This leads to greater uncertainties when assessing the statistical significance of observed changes.

Scientific references:

• IPCC, 2007. Cimate Change: The Physical Science Basis Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Solomon, S.; Qin, D.; Manning, M.; Chen, Z.; Marquis, M.; Averyt, K. B.; Tignor M. and Miller H. L. (eds.), Cambridge University Press, Cambridge, UK.

Indicator definition

• Trends in consecutive wet days and consecutive dry days

• Projected changes in 20-year maximum precipitation in summer and winter

Units

• dry days/decade
• wet days/decade
• %

Policy context and targets

Context description

In April 2009 the European Commission presented a White Paper on the framework for adaptation policies and measures to reduce the European Union's vulnerability to the impacts of climate change. The White Paper stresses the need to improve the knowledge base and to mainstream adaptation into existing and new EU policies. The European Commission will be publishing an EU Adaptation Strategy in 2013. A number of Member States have already taken action, and several have prepared national adaptation plans.

The European Commission and the European Environment Agency have developed the European Climate Adaptation Platform (Climate-ADAPT, http://climate-adapt.eea.europa.eu/) to share knowledge on observed and projected climate change and its impacts on environmental and social systems and on human health; on relevant research; on EU, national and subnational adaptation strategies and plans; and on adaptation case studies.

Targets

No targets have been specified.

Related policy documents

• Climate-ADAPT: Mainstreaming adaptation in EU sector policies
  Overview of EU sector policies in which mainstreaming of adaptation to climate change is ongoing or explored
• Climate-ADAPT: National adaptation strategies
  Overview of activities of EEA member countries in preparing, developing and implementing adaptation strategies
• DG Climate Action: What is the EU doing about climate change?
  Activities of the EU regarding climate change (both mitigation and adaptation)
• White paper - Adapting to climate change: towards a European framework for action
  EU framework for adaptation to climate change, leading to a comprehensive EU adaptation strategy by 2013

Methodology

Methodology for indicator calculation

The number of consecutive wet days is defined as the number of days in a row during which every day is a wet day (daily precipitation amounts are more than 1 mm in every day during the period). Respectively, consecutive dry days show less than 1 mm per day.

Precipitation extremes over Europe are examined in an ensemble of RCA3 regional climate model simulations driven by six different global climate models (ECHAM5, CCSM3, HadCM3, CNRM, BCM and IPSL) under the SRES A1B emission scenario. The extremes are expressed in terms of the 20-yr return values of seasonal precipitation extremes.

Methodology for gap filling

Not applicable

Methodology references

• Nikulin et al. 2011: Evaluation and future projections of temperature, precipitation and wind extremes over Europe in an ensemble of regional climate simulations Grigory Nikulin, Erik Kjellström, Ulf Hansson, Gustav Strandberg, Anders Ullerstig (2011):Evaluation and future projections of temperature, precipitation and wind extremes over Europe in an ensemble of regional climate simulations. Tellus A, Volume 63(1): 41–55 . DOI: 10.1111/j.1600-0870.2010.00466.x

Data specifications

EEA data references

• No datasets have been specified here.

External data references

• Evaluation and future projections of temperature, precipitation and wind extremes over Europe in an ensemble of regional climate simulations
• E-OBS gridded dataset

Data sources in latest figures

Uncertainties

Methodology uncertainty

Not applicable

Data sets uncertainty

The risks posed by precipitation-related hazards, such as flooding events (including flash floods) and landslides, are also influenced by non-climatic factors, such as population density, floodplain development and land-use change. Hence, estimates of future changes in such risks need to consider changes in both climatic and non-climatic factors. Estimates of trends in heavy or extreme precipitation are more uncertain than trends in mean precipitation because, by their very nature, extreme precipitation events have a low frequency of occurrence. This leads to greater uncertainties when assessing the statistical significance of observed changes.

Further information on uncertainties is provided in Section 1.7 of the EEA report on Climate change, impacts, and vulnerability in Europe 2012 (http://www.eea.europa.eu/publications/climate-impacts-and-vulnerability-2012/

Rationale uncertainty

No uncertainty has been specified