Water and Climate Change
Theme leader: Anders Erichsen, Senior Engineer at DHI Water, Environment & Health
In both core and applied research and also increasingly in managing and governing bodies there are a comprehensive understanding and an acknowledgement of climate change impacts on water volume and movement. The IPCC scenarios predict major global and regional changes in rainfall patterns and sea-level rise due to increasing temperatures.
The water quality problems are many and complex. We would therefore like to dedicate the water sessions to the 1st and 2nd order effects of climate change on water quality and aquatic ecosystems, - and challenge participants to contribute with intriguing research results, examples of state of art assessment tools and hair-raising examples - case stories from real life .
Session: Marine and river basin water quality and ecosystem assessment and management in a changing climate
Klaus Hinsby, GEUS: Integrated assessment of climate change and sea level rise on the water quality of a coastal lake
An integrated and distributed hydrological model was constructed for a coastal catchment on the island of Zealand, Denmark. Water supply in the area depends on abstraction from a relatively large lake located close to the sea. It is shown that the quantity of fresh water in a future climate is predicted to be sufficient to sustain water abstraction even though precipitation decreases during the summer period. However, the rising sea water level results in inflow of saltwater to the lake especially during late summer and autumn where the lake water level is relatively low and storm events results in high sea levels. The study shows that adaptation measures are needed already at a sea level rise of approximately 0.5 m if salt water inflow should not destroy the lake as a fresh water resource.
Brian Kronvang, National Environmental Research Institute, Aarhus University: Runoff, nutrient loads and freshwater ecology in a changing climate in Denmark: what can we learn from historical data and model scenarios?
Changes in the hydrology of Danish lowland rivers towards more water in general, more extreme conditions and changes in seasonality will have direct impacts on the amount of water in the landscape (floods, droughts, drainage of agricultural land) and spin off effects on the concentration and loads of sediment and nutrients to the aquatic environment. The combination of increasing runoff and rising temperature can impact the critical recruitment periods for trout in streams and have other negative effects for other cold water species presently used as indicators for the ecological quality of Danish streams. The usefulness of combining long term monitoring data for hindcasting effects of climate change with models simulations for forecasting the effects of climate change is demonstrated for different regions and cases in Denmark
Paul Buckley, Cefas: Delivering ‘science to stakeholders’ through the UK Marine Climate Change Impacts Partnership (MCCIP)
The UK Marine Climate Change Impacts Partnership (MCCIP) was established in 2005 to help facilitate the transfer of peer-reviewed science to decision makers. Our latest synthesis report card, published in July 2010, covers 30 marine topics ranging from acidification to aquaculture and salinity to shipping. It includes contributions from almost 100 scientists spread across 40 research institutes.
Here we discuss our experiences of engaging both scientific and stakeholder communities into the MCCIP process. The continuing challenge of communicating evidence in a way that fairly represents the scientific community is highlighted, along with the challenges of translating an often limited science evidence base into adaptation priorities and actions for marine stakeholder communities.
Useful Links
Henrik Bay, Administration Manager, Environment, Fehmern Belt A/S: Implementation of predicted climate changes in the planning of a fixed link across Fehmarnbelt.
Predicted climate changes will be implanted in the design of the fixed link and the EIA will also be based on predicted climate changes. Although research today has demonstrated that a number of robust changes are emerging within the global warming picture uncertainties remain relatively large. This is mainly due to a limited knowledge of the climate system and its variability, errors in models as well as lack of certainty in future greenhouse gas emissions.
A few clear signals reflecting on of a broad physical understanding and converging model results are evident, if a likely upper limit of change is to be assessed. Annual mean temperatures in Denmark could increase as much as 6 degrees in a very extreme warming scenario. Conditions with sea ice around Denmark will become extremely rare. In addition incidences with severe snow related weather conditions will become rarer with increasing temperature. Annual precipitation amounts are likely to increase, but with a pronounced change in the seasonality, with wetter winters and most like drier summers. This is accompanied by an increase in 10 year (and possibly for 50 and 100 year) return values of daily precipitation amounts.
A preliminary analysis suggests an increase in the 50‐year extreme wind by 3m/s (10 min average; 10 m height) i.e. from 27 to 30 m/s at the end of the century. More analysis is needed to quantify changes in intense wind speeds in the 15 to 35 m/s range, which are important for operation of a bridge in 80 to 100 height above sea level. Sea level is projected to increase even if emissions are kept at a minimum. Uncertainty related to the fate of the Greenland and Antarctic ice sheets, imply that sea level rise in Denmark of 1m within the coming century could be realised. Weather related phenomenon, in particular icing and visibility, are nor well analysed and further work on the analysis of model simulations are needed to provide any information with a reasonable credibility.