Snow cover

Assessment versions

Published (reviewed and quality assured)

• Snow cover (CLIM 008) - Assessment published Nov 2012

Justification for indicator selection

Snow influences the climate and climate-related systems because of its high reflectivity, insulating properties, effects on water resources and ecosystems, and cooling of the atmosphere. A decrease in snow cover contributes to accelerated climate change.

In Europe about half of the 800 million people live on areas that have snow cover in January in an average winter. Changes in snow cover affect human well-being through effects on water availability, hydropower, navigation, infrastructure, the livelihoods of indigenous Arctic people, environmental hazards, winter recreation and outdoor light conditions. Variation in snow cover affects winter road and rail maintenance, and the exploitation of natural resources in cold regions. Snow cover is most sensitive to climate change at low elevations in temperate regions.

Scientific references:

• UNEP, 2007. Global outlook for snow and ice. UNEP Arendal/ Nairobi 2007.
• ACIA 2005: Impacts of a Warming Arctic Arctic Climate Impact assessment. Cambridge University Press, Cambridge, UK.

Indicator definition

• Trend in autumn, winter and spring snow cover extent over the Northern Hemisphere

• Trend in March snow mass in Europe (excluding mountain areas)

• Projected changes in annual snowfall days

Units

• million km²
• %
• days/year

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

Satellite observations on the monthly snow cover extent in the Northern Hemisphere are available since November 1966 from the Rutgers University Global Snow Lab and from the Globsnow project. Trend lines have been added.

Multi-model mean of changes in annual snowfall days from 1971–2000 to 2041–2070 exceeding 1 cm and 10 cm are based on 6 RCM simulations and the emission scenario A1B.

Methodology for gap filling

Not applicable

Methodology references

• Vajda et al. 2012: Probabilities of adverse weather affecting transport in Europe Vajda, A., Tuomenvirta, H., Jokinen, P., Luomaranta, A., Makkonen, L., Tikanmäki, M., Groenemeijer, P., Saarikivi, P., Michaelides, S., Papadakis, M., Tymvios, F. and Athanasatos, S. (2011) Probabilities of adverse weather affecting transport in  Europe: climatology and scenarios up to the 2050s. Reports 2011(9).
• RUGSL (2011) Fall, Winter, and Spring Northern Hemisphere Snow Cover Extent RUGSL (2011) Fall, Winter, and Spring Northern Hemisphere Snow Cover Extent from the Rutgers University Global Snow Lab. Climate Science: Roger Pielke Sr.
• Luojus et al. 2012: Final Report. GlobSnow Deliverable 3.5. GlobSnow. Luojus, K., Pulliainen, J., Takala, M., Lemmetyinen, J., Kangwa, M., Sohlberg, R., Nagler, T., Rott, H., Derksen, C., Wiesmann, A., Metsämäki, S. and Bojkov, B. (2011) Final Report. GlobSnow Deliverable 3.5. GlobSnow.

Data specifications

EEA data references

• No datasets have been specified here.

External data references

• Fall, Winter, And Spring Northern Hemisphere Snow Cover Extent
• Projected changes in annual snowfall days
• Final Report. GlobSnow Deliverable 3.5. GlobSnow.

Data sources in latest figures

Uncertainties

Methodology uncertainty

Not applicable

Data sets uncertainty

Data on the cryosphere vary significantly with regard to availability and quality. Snow and ice cover have been monitored globally since satellite measurements started in the 1970s. Improvements in technology allow for more detailed observations and higher resolution. High quality long-term data is also available on glaciers throughout Europe.

Continuous efforts are being made to improve on knowledge of the cryosphere. Intensive development work is under way to develop projections, which are essential for scenarios of climate change impacts and adaptation. Due to their economic importance special effort is also devoted to improving real-time monitoring of, for example, snow cover.

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