Growing season for agricultural crops (CLIM 030) - Assessment published Nov 2012
Climate change (Primary topic)
Typology: Descriptive indicator (Type A - What is happening to the environment and to humans?)
- CLIM 030
- Change in the number of frost-free days per year
Key policy question: How is climate change affecting the growing season for agricultural crops?
- The thermal growing season of a number of agricultural crops in Europe has lengthened by 11.4 days on average from 1992 to 2008. The delay in the end of the growing season was more pronounced than the advance of its start.
- The growing season is projected to increase further throughout most of Europe due to earlier onset of growth in spring and later senescence in autumn.
- The projected lengthening of the thermal growing season would allow a northward expansion of warm-season crops to areas that were not previously suitable.
Change in the number of frost-free days per year
Note: This figure shows the rate of change in the growing season length (defined as the number of frost-free days per year) during the period January 1975 – December 2010.
- Rate of change of frost-free period map for Europe provided by Geo network - open source
Increasing air temperatures are significantly affecting the duration of the growing season over large areas of Europe [i]. Many studies report a lengthening of the period between the occurrence of the last spring frost and the first autumn frost. This has occurred in recent decades in several areas in Europe and more generally in the Northern Hemisphere [ii]. Studies of changes in the growing season based on remote sensing show a diverse spatial pattern in Europe [iii]. Across all of Europe, the delay in end of the season of the period 1992–2008 by 8.2 days was more significant than the advanced start of the season by 3.2 days [iv].
An analysis of the frost-free period in Europe between 1975 and 2010 shows a general and clear increasing trend. The trend is not uniformly spread over Europe. The highest rates of change (larger than 0.8 days per year) were recorded along the Atlantic shores, in the British Isles, Denmark, central parts of Europe, central Italy, central and southern Spain, and in Turkey (Figure 1). There are also areas in Europe with an apparent trend for reductions in the frost-free period; however, these trends are not significant.
A warming of the climate is expected mainly to result in an earlier start of the growing season in spring and a longer duration in autumn [v]. A longer growing season allows the proliferation of species that have optimal conditions for growth and development and can thus increase their productivity or number of generations (e.g. crop yield, insect population). This will in many cases also allow for introduction of new species previously unfavourable due to low temperatures or short growing seasons. This is relevant for introduction of new crops, but will also affect the spreading of weeds, insect pests and diseases [vi].
A further lengthening of the growing season as well as a northward shift of species is projected as a result of the projected further increase in temperature across Europe [vii]. The date of last frost in spring is projected to advance by about 5–10 days by 2030 and by 10–15 days by 2050 throughout most of Europe [viii]. The suitability for growing certain crops will also depend on the total amount of heat received during the growing season expressed as a temperature sum. Projections show the greatest absolute increases in temperature sum in southern Europe, whereas relative changes are much larger in northern than in southern Europe [ix].
The extension of the growing season is expected to be particularly beneficial in northern Europe, where new crops could be cultivated and where water availability is generally not restricting growth [x]. In parts of the Mediterranean area the cultivation of some crops may shift from the summer season to the winter season, which could offset some of the negative impacts of heat waves and droughts during summer [xi]. Other areas of Europe, such as western France and parts of south-eastern Europe, will experience yield reductions from hot and dry summers without the possibility of shifting the crop production into the winter seasons.
[i] H. Scheifinger et al., „Trends of spring time frost events and phenological dates in Central Europe“, Theoretical and Applied Climatology 74 (Januar 1, 2003): 41–51, doi:10.1007/s00704-002-0704-6.
[ii] M Trnka et al., „A 200-year climate record in Central Europe: implications for agriculture“, Agronomy for Sustainable Development 31 (Juni 7, 2011): 631–641, doi:10.1007/s13593-011-0038-9.
[iii] Mark D Schwartz, Rein Ahas, and Anto Aasa, „Onset of Spring Starting Earlier Across the Northern Hemisphere“, Global Change Biology 12, Nr. 2 (Februar 1, 2006): 343–351, doi:10.1111/j.1365-2486.2005.01097.x.
[iv] Su‐jong Jeong et al., „Phenology Shifts at Start Vs. End of Growing Season in Temperate Vegetation over the Northern Hemisphere for the Period 1982–2008“, Global Change Biology 17, Nr. 7 (Juli 1, 2011): 2385–2399, doi:10.1111/j.1365-2486.2011.02397.x.
[v] Jeong et al., „Phenology Shifts at Start Vs. End of Growing Season in Temperate Vegetation over the Northern Hemisphere for the Period 1982–2008“.
[vi] Jonas Roos et al., „The impact of global warming on plant diseases and insect vectors in Sweden“, European Journal of Plant Pathology 129 (Oktober 2, 2010): 9–19, doi:10.1007/s10658-010-9692-z.
[vii] J.E. Olesen et al., „Impacts and adaptation of European crop production systems to climate change“, European Journal of Agronomy 34, Nr. 2 (Februar 2011): 96–112, doi:10.1016/j.eja.2010.11.003.
[viii] M. Trnka et al., „Agroclimatic Conditions in Europe Under Climate Change“, Global Change Biology 17, Nr. 7 (Juli 1, 2011): 2298–2318, doi:10.1111/j.1365-2486.2011.02396.x.
[ix] Trnka et al., „Agroclimatic Conditions in Europe Under Climate Change“.
[x] Olesen et al., „Impacts and adaptation of European crop production systems to climate change“.
[xi] M. I. Minguez et al., „First-order impacts on winter and summer crops assessed with various high-resolution climate models in the Iberian peninsula“, Climatic Change 81, Nr. Supplement 1 (2007): 343–355, doi:10.1007/s10584-006-9223-2.
Monitoring Agricultural ResourceS (MARS)
provided by Joint Research Centre (JRC)
Policy context and targets
In April 2013 the European Commission presented the EU Adaptation Strategy Package (http://ec.europa.eu/clima/policies/adaptation/what/documentation_en.htm). This package consists of the EU Strategy on adaptation to climate change /* COM/2013/0216 final */ and a number of supporting documents. One of the objectives of the EU Adaptation Strategy is Better informed decision-making, which should occur through Bridging the knowledge gap and Further developing Climate-ADAPT as the ‘one-stop shop’ for adaptation information in Europe. Further objectives include Promoting action by Member States and Climate-proofing EU action: promoting adaptation in key vulnerable sectors. Many EU Member States have already taken action, such as by adopting national adaptation strategies, and several have also prepared action plans on climate change adaptation.
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.
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 CLIMA: Adaptation to climate change
Adaptation means anticipating the adverse effects of climate change and taking appropriate action to prevent or minimise the damage they can cause, or taking advantage of opportunities that may arise. It has been shown that well planned, early adaptation action saves money and lives later. This webportal provides information on all adaptation activities of the European Commission.
EU Adaptation Strategy Package
In April 2013 the European Commission adopted an EU strategy on adaptation to climate change which has been welcomed by the EU Member States. The strategy aims to make Europe more climate-resilient. By taking a coherent approach and providing for improved coordination, it will enhance the preparedness and capacity of all governance levels to respond to the impacts of climate change.
Methodology for indicator calculation
The map has been produced querying a database, internal to Joint Research Centre (JRC), containing meteo data at 25 kilometers grid level, interpolated from meteo station data. The interpolation is performed taking into account only arable land, potentially suitable for crop growth. The meteo data are provided to JRC in the frame of the MARSOP 3 contract, complying with Council Regulation (EC) No 78/2008 of 21 January 2008 on the measures to be undertaken by the Commission in 2008-2013 making use of the remote-sensing applications developed within the framework of the common agricultural policy, Official Journal of the European Union, L 25 of 30 January 2008, p. 1.
Methodology for gap filling
No methodology references available.
Data sets uncertainty
Effects of climate change on the growing season and crop phenology can be monitored directly, partly through remote sensing (growing season) and partly through monitoring of specific phenological events such as flowering. There is no common monitoring network for crop phenology in Europe, and data on this therefore has to be based on various national recordings, often from agronomic experiments. Crop yield and crop requirements for irrigation are not only affected by climate change, but also by management and a range of socio-economic factors. The effects of climate change on these factors therefore have to be estimated indirectly using agrometeorological indicators and through statistical analyses between climatic variables and factors such as crop yield.
The projections of climate change impacts and adaptation in agriculture rely heavily on modelling, and it needs to be recognised that there is often a chain of uncertainty involved in the projections going from emission scenario, through climate modelling, downscaling and to assessments of impacts using an impact model. The extent of all these uncertainties is rarely quantified, even though some studies have assessed uncertainties related to individual components. The crop modelling community has only recently started addressing uncertainties related to modelling impacts of climate change on crop yield and effect of possible adaptation options, and so far only few studies have involved livestock systems. Future studies also need to better incorporate effects of extreme climate events as well as biotic hazards (e.g. pests and diseases).
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/)
No uncertainty has been specified
More information about this indicator
See this indicator specification for more details.
Contacts and ownership
EEA Contact InfoHans-Martin Füssel
EEA Management Plan2012 2.0.1 (note: EEA internal system)
Frequency of updates
For references, please go to www.eea.europa.eu/soer or scan the QR code.
This briefing is part of the EEA's report The European Environment - State and Outlook 2015. The EEA is an official agency of the EU, tasked with providing information on Europe’s environment.
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