Climate: Observations, projections and impacts: Germany Met Office Simon N. Gosling, University of Nottingham Robert Dunn, Met Office Fiona Carrol, Met Office Nikos Christidis, Met Office John Fullwood, Met Office Diogo de Gusmao, Met Office Nicola Golding, Met Office Lizzie Good, Met Office Trish Hall, Met Office Lizzie Kendon, Met Office John Kennedy, Met Office Kirsty Lewis, Met Office Rachel McCarthy, Met Office Carol McSweeney, Met Office Colin Morice, Met Office David Parker, Met Office Matthew Perry, Met Office Peter Stott, Met Office Kate Willett, Met Office Myles Allen, University of Oxford Nigel Arnell, Walker Institute, University of Reading Dan Bernie, Met Office Richard Betts, Met Office Niel Bowerman, Centre for Ecology and Hydrology Bastiaan Brak, University of Leeds John Caesar, Met Office Andy Challinor, University of Leeds Rutger Dankers, Met Office Fiona Hewer, Fiona's Red Kite Chris Huntingford, Centre for Ecology and Hydrology Alan Jenkins, Centre for Ecology and Hydrology Nick Klingaman, Walker Institute, University of Reading Kirsty Lewis, Met Office Ben Lloyd-Hughes, Walker Institute, University of Reading Jason Lowe, Met Office Rachel McCarthy, Met Office James Miller, Centre for Ecology and Hydrology Robert Nicholls, University of Southampton Maria Noguer, Walker Institute, University of Reading Friedreike Otto, Centre for Ecology and Hydrology Paul van der Linden, Met Office Rachel Warren, University of East Anglia The country reports were written by a range of climate researchers, chosen for their subject expertise, who were drawn from institutes across the UK. Authors from the Met Office and the University of Nottingham collated the contributions in to a coherent narrative which was then reviewed. The authors and contributors of the reports are as above. Developed at the request of: Climate: Observations, projections and impacts Research conducted by: Germany We have reached a critical year in our response to There is already strong scientific evidence that the climate change. The decisions that we made in climate has changed and will continue to change Cancún put the UNFCCC process back on track, saw in future in response to human activities. Across the us agree to limit temperature rise to 2 °C and set us in world, this is already being felt as changes to the the right direction for reaching a climate change deal local weather that people experience every day. to achieve this. However, we still have considerable work to do and I believe that key economies and Our ability to provide useful information to help major emitters have a leadership role in ensuring everyone understand how their environment has a successful outcome in Durban and beyond. changed, and plan for future, is improving all the time. But there is still a long way to go. These To help us articulate a meaningful response to climate reports – led by the Met Office Hadley Centre in change, I believe that it is important to have a robust collaboration with many institutes and scientists scientific assessment of the likely impacts on individual around the world – aim to provide useful, up to date countries across the globe. This report demonstrates and impartial information, based on the best climate that the risks of a changing climate are wide-ranging science now available. This new scientific material and that no country will be left untouched by climate will also contribute to the next assessment from the change. Intergovernmental Panel on Climate Change. I thank the UK’s Met Office Hadley Centre for their However, we must also remember that while we hard work in putting together such a comprehensive can provide a lot of useful information, a great piece of work. I also thank the scientists and officials many uncertainties remain. That’s why I have put in from the countries included in this project for their place a long-term strategy at the Met Office to work interest and valuable advice in putting it together. ever more closely with scientists across the world. I hope this report will inform this key debate on one Together, we’ll look for ways to combine more and of the greatest threats to humanity. better observations of the real world with improved computer models of the weather and climate; which, The Rt Hon. Chris Huhne MP, Secretary of State for over time, will lead to even more detailed and Energy and Climate Change confident advice being issued. Julia Slingo, Met Office Chief Scientist Introduction Understanding the potential impacts of climate change is essential for informing both adaptation strategies and actions to avoid dangerous levels of climate change. A range of valuable national studies have been carried out and published, and the Intergovernmental Panel on Climate Change (IPCC) has collated and reported impacts at the global and regional scales. But assessing the amount of information about past climate change and its future impacts has been available at Each report contains: data on extreme events. Fourth Assessment Report from the IPCC. Dangerous Climate Change programme (AVOID) and supporting literature. through international cooperation. Summary Climate observations Over the period 1960 to 2010 there was a consistent warming over Germany. There has been a substantial decrease in the frequency of cool nights and cool days since 1960 and a strong increase in the numbers of warm nights and warm days. There has been a general increase in summer temperatures averaged over the country as a result of human influence on climate, making the occurrence of warm summer temperatures more frequent and cool summer temperatures less frequent. Climate change projections For the A1B emissions scenario projected increases in temperature range from around 2.5 to 3.5°C over Germany with the agreement between models being moderate over most of the country, but with areas of high agreement in the far south. Germany is located in the transition zone between projected increasing precipitation over Northern Europe, and decreases in Southern Europe. Northern parts of Germany are projected to experience increases of up to 10%, whereas the far south has projected decreases of up to 5%. The ensemble agreement over this region is generally moderate, and reflects uncertainty about the precise location of the transition between increasing and decreasing precipitation over Europe. Climate change impact projections Crop yields Global-scale studies generally project yield increases by the end of the century for wheat and maize, two of Germany’s major crops, along with increased land suitability. 1 However the balance between detrimental ozone effects and CO2 fertilisation may determine whether crop yield losses or gains are realised under climate change. A number of sub-national-scale assessments included here suggest that climate change could be beneficial for the wine and fruits industry in Germany. Food security Germany is currently a country with extremely low levels of undernourishment. Global-scale studies included here generally project that Germany will not face serious food security issues over the next 40 years as a consequence of climate change, especially considering its strong purchasing power and substantial adaptive capacity. Water stress and drought Over 70% of Germany’s current water supply is from groundwater. Global-scale studies included here which consider future groundwater withdrawals with climate change suggest that Germany is not particularly vulnerable to increased water stress in the future. In contrast, simulations from the AVOID programme project a median increase of around 40% of Germany’s population to be exposed to water stress increases by 2100 under SRES A1B. However, the methodology for this study only accounts for changes in run-off, rather than changes in groundwater directly. National-scale studies included here suggest that it is possible that droughts could become more frequent with climate change in the east of the country and although annual precipitation may not change, that there could be higher drought risk in summer months. Pluvial flooding and rainfall Large-scale modelling studies support conclusions from the IPCC AR4 that heavy winter precipitation and flooding could increase with climate change for Germany. However, recent national-scale assessments suggest that increasing trends in precipitation with climate change for Germany are relatively small when compared with emissions uncertainty and that trends of increasing rainfall with climate change may not be significant. 2 Fluvial flooding Climate change could be associated with increases in fluvial flooding for some parts of Germany, particularly the Rhine basin. However, projections of future changes in flood hazard are subject to large uncertainties due to large natural variability as well as large uncertainties in the simulated climate change. Simulations from the AVOID programme show a greater tendency towards decreasing flood risk in Germany at first, but later in the century more projections indicate increasing flood risk under the A1B scenario. Coastal regions Germany has coasts on both the North and Baltic Seas extending over five coastal states. Large-scale and national-scale studies suggest that without adaptation, the number of people at risk from coastal flooding in Germany due to Sea Level Rise (SLR) under climate change scenarios could be around 300,000. However, these impacts could be reduced substantially by adaptation and climate change mitigation measures. One study demonstrates