the eawag workshop on climate and water preliminary summary of results and implications for bundling...

The Eawag Workshop on Climate and Water

Preliminary summary of results and implications for bundling relevant future research at Eawag

Special thanks to the working group leaders:

Jürg Beer (Global issues)Flavio Anselmetti (Palæolimnology)Bas Ibelings (Aquatic ecosystems)Ole Seehausen (Fish)Olaf Cirpka (Groundwater)Urs von Gunten (Drinking water and water technology)Andreas Klinke (Societal issues)

and to all the rest of you who participated!

Brief history of the topicPreliminary summary of main results of workshopSome suggestions for common researchPlenary discussionSummary

Climate and zooplankton, UK

George & Harris (1985): Nature 316, 536-539.

"Year-to-year fluctuations in the biomass of crustacean zooplankton in Lake Windermere are strongly correlated with variations in water temperature, but poorly correlated with the abundance of the dominant planktivorous fish.”

Air and water temperatures in the Lake District are strongly related to the sea-surface temperature to the west of the UK, implying a large-scale climatic influence.

"This represents the first conclusive evidence of climatologically induced variability in a freshwater planktonic system."

George & Taylor (1995): Nature 378, 139.

Zooplankton biomass related to position of the north wall of the Gulf Stream

Climate-related regional coherence

Magnuson, Benson & Kratz (1990): Freshw. Biol. 23, 145-159.

Lakes in N. Wisconsin connected by:(i) common climatic forcing(ii) groundwater flow

"Coherence between lakes was greater for limnological variables directly influenced by climatic factors than for variables either indirectly affected by climate of complexly influenced by other types of factors"

“Lake 239” (ELA, Ontario), 1969-1988

Schindler, Beaty, Fee, Cruikshank, DeBruyn, Findlay, Linsey, Shearer, Stainton & Turner (1990): Science 250, 967-970.

EU projects (with Eawag involvement)

Coordinated by Glen George• EU FP4 project "REFLECT" (1998–2000)• EU FP5 project "CLIME" (2001-2003)

Coordinated by Rick Battarbee• EU FP3 project "MOLAR" (1996-1999)• EU FP5 project "EMERGE" (2000-2003)• EU FP6 project "Euro-limpacs" (2004-2009)

Relevant international research networks(initiated by John Magnuson and coworkers)

• LTER (Long Term Ecological Research)• LIAG (Lake Ice Analysis Group)• GLEON (Global Lake Ecological Observatory Network)

Global aspectsWhat contribution can we make to solving global-scale climate-change problems?

1) Work is already ongoing on global-scale problems relevant to climate changeFor example:- Greenhouse gases (CH4)- Solar forcing (Be in Greenland ice)- Adapt approach to existing global-scale problems to allow for the expected impacts of climate change? E.g. SODIS; Arsenic in groundwater.

2) The predicted main changes are a shift in mean values and, more importantly, an increase in variability- Reconstruction of past climate change and “intelligent monitoring” of present climate change at carefully selected sites

• “Space-for-time substitution” and “Space-for-space substitution”Climate change results in a horizontal shift of climate zones over hundreds to thousands of kilometres. Translated to altitude, the same shifts correspond merely to hundreds of metres.The selection of 3-4 ecosystems at different altitudes in the Alps would offer the opportunity to study large-scale climate shifts within Switzerland (analogues)

4) Water availability and water quality in mountain regionsMany aspects apparently specific to the Alps are actually also relevant to other mountain regions: transfer of know-how.

PalæolimnologyUsing the past as the key to the future

1) Lake sediments enable us to quantify natural climate variability, thus allowing predicted changes to be put into historical perspectiveWarmer time windows in the Holocene can be used as analogues for future climate scenarios (How will the future be? Look into the past!)

2) Climate change as a driver of ecosystem change in the pastLake sediments archive various proxies that document past physical, chemical and biological changes in the ecosystem in response to various past climates. This allows the impact of past climate change on these ecosystems to be assessed.

3) A gap to be filled: past and future changes in precipitationThe natural range in precipitation (extreme events/floods and background values) have so far not been quantified, although these are crucial in future climate scenarios and for the assessment of natural hazards. Investigation of critical proxies for precipitation.

4) Again: “space-for-space substitution”Climate change has a stronger impact at high latitudes than at low latitudes. The impact of past climates on a vertical gradient of environments (rather than a horizontal one) could be investigated in the Alpine area.

Aquatic ecosystemsFrom monitoring to understanding, predicting and managing

the effects of climate change on aquatic ecosystems

1) Monitoring - Set up and maintain ‘clever’ monitoring systems that will capture the true dynamics of changing aquatic ecosystems, e.g. community dynamics. (GLEON...)

2) Understanding - Which changes in water quality and in aquatic ecosystems can be demonstrably attributed to climate change? - What determines the resilience of the response of ecosystems to change? - What is the capacity of ecosystems to adapt?

3) Predicting Use a deepened understanding of the effects of climate change on aquatic ecosystems to improve, calibrate and validate ecosystem models.

4) Managing Incorporate the adaptive responses of society into the study of ecosystem change.

FishBackground, objectives and current limitations

Objective of a research program “climate and fish”:

Understanding and predicting responses of fish assemblages to climate change

Current limitations:

1. Lack of quantitative data on fish communities in Swiss lakes and rivers

2. Limited understanding of relative importance of and interaction between abiotic and biotic climate-driven stressors

3. Limited understanding of potential responses of fish species to climate change

Broad agreement that:

1. Fish communities are changing rapidly. Patterns are poorly documented, drivers are poorly understood. There are strong indications that climate change is an important driver.

2. Switzerland is a hotspot of diversity and endemism of cold-adapted fish species. Several have already become extinct

3. Switzerland is geographically uniquely positioned for research on climate change impacts on fish, and we think it is highly relevant to Eawag‘s mission

FishAn integrated programme “climate and fish” would include:

1. Literature analyses and formal meta-analyses, relying on data mostly from other regions of the world, but also Swiss grey literature. These would address a number of key issues that would guide the data collection strategy.

2. Generation of a time zero+ baseline data set on fish community composition and genetic diversity in the major Swiss lakes and rivers.

3. Establishment of long-term data series in a network of waters covering elevational gradients and the biogeographical regions.

4. Hypothesis-driven experimental work to quantify the potential of evolutionary response to climate change in key species.

5. Theoretical and quantitative ecological and genetic modelling to integrate these parallel approaches.

GroundwaterThe impact of climate and environmental change on aquifers

1) Direct impacts of climate change on groundwater bodies are probably less important than indirect impacts

- Changes in land use, agricultural practice, legislation- Factor environmental change into integrated water resources management

2) In CH: Impact of droughts is more important than the impact of warming- Needed: Vulnerability study of Swiss aquifers

3) Key project in CH: Follow the process chain from environmental changes to groundwater quality

- Needed: Well studied aquifer system + calibrated model- Hypothesis: Change in hydrology change in groundwater hydrogeochemistry

threat to current practice of groundwater use

4) Eawag‘s contribution to climate and groundwater in semi-arid regions: Geogenic pollution in a changing climate

Drinking water and water technology issues

1) Changes in river discharge (proportion of wastewater) → Effect on groundwater quality? Upgrading of wastewater treatment?

2) Changes in agricultural practices (irrigation, changes in application of fertiliser, manure, pesticides) → Effects on groundwater quality and quantity

3) Changes in temperature and mixing regimes of lakes → Effect on phytoplankton and cyanobacterial population, taste and odour, cyanotoxins. Adequate treatment?

4) Institutional/organisational problems in coping with the effects of climate change on water supplies

Societal issuesGovernance and research approaches

1) Governance in Switzerland - Resilience and flexibility of current water management systems- Adequacy of current regulations and management practices (including monitoring) to

tackle the relationship between water resources and climate- Integration of stakeholders to understand and deal with emerging problems better- Integrated water resource management

2) Governance in developing and transition countries - High vulnerability of urban water systems- Development of technological and organisational solutions- Capacity building and empowerment

3) Interdisciplinary and transdisciplinary research approaches

4) Involvement of Eawag with international bodies(e.g., WMO, IPCC, FAO, UNESCO, UNEP...)

Some common and important issues

1) Reconstructing the past and monitoring the present - “intelligent monitoring” (referring to human intelligence) and “clever monitoring” (referring to the capabilities of the monitoring system)

2) Understanding processes - because understanding is a prerequisite to robust modelling

3) Broadness of approach - interdisciplinary, international, cooperative, involving stakeholders and external partners

4) Distinguish between:(i) environmental change that is the direct result of climate change; (ii) environmental change that is the indirect result of climate change; and (iii) environmental change that is unconnected with climate change.



Direct:- Interface between climate and aquatic physics (e.g., shifts in the heat balance of lakes and rivers; shifts in the phenology of ice and of mixing). But there are some direct biological and chemical effects (e.g. impact of changes in cloud cover on photosynthesis; impact of changing air temperature on pH in catchments).

Indirect:- Interface between aquatic physics and other aquatic disciplines - climate is not directly involved. E.g. Impacts of higher water temperatures on phytoplankton (mesocosm experiments) or on fish habitats.

Unconnected:- Impacts of urbanisation, new technologies, global and local economics, population shifts, legislation changes, agricultural practices etc. etc. etc..... Essentially unpredictable in the long term.



So why should we bother studying the impacts of climate change on water resources when the impacts of other types of environmental change (e.g. social change) that are much less quantifiable are likely to be greater?- What we can predict, we should.- It is important to establish a “framework of thought” well in advance of the strongest impacts - i.e., to be intellectually prepared. The models (even intellectual, conceptual models) have to be in place in good time so they can be employed, refined and made more quantifiable closer to the time of impact, when the social changes are easier to predict than now.

Water resources as an endangered species

Agriculture Industrial / urban / natural contamination Conflicts: ecology groundwater protection Climate: quantity (spring water!) Quality (change in redox, input of nutrients, physical conditions, hygiene, etc...)

AgricultureU-Chem

EcoGWPEco, Surf,

W+T

ContaminationIng, Sandec,

U-Chem, U-Mik

ContaminationW+T, WRQ

ClimateSiam

ClimateSurf, W+T, Eco

ClimateW+T

Some questions addressed by:QP: Wave 21, WRQCCES: Record

Record

Wave 21

WRQ

3 points to discuss • 'WRQ' maps: CH climate • Natural analogues • Lakes: integrated models coupling: climate, physics, water quality & biology

3 points to discuss • 'WRQ' maps: CH climate • Natural analogues • Lakes: integrated models coupling: climate, physics, water quality & biology

Vertical “space-for-time” or “space-for-space” analogueUsing altitudinal shifts as a proxy for climate warming

.

-5 0 5 10 15 20 250

1000

2000

3000

4000

c) September 2000-5 0 5 10 15 20 25

Air temperature (°C)

b) August 20000

1000

2000

3000

4000

-5 0 5 10 15 20 25

a) July 2000

Livingstone, Lotter & Kettle (2005)

Decrease in surface air temperature with increasing altitude in Switzerland(based on data from 40 meteorological stations)

6.1 K km-1 5.6 K km-1 5.1 K km-1

.

050010001500200025003000Altitude distribution of 107 lakes in the Canton of Berne, Switzerland

Data from Guthruf, Guthruf-Seiler & Zeh (1999)

Choose ~4-5 lakes covering an altitudinal gradient, e.g.

Hagelseewli 2339 m a.s.l. / 19 m / 25x103 m2

Seebergsee 1831 m a.s.l. / 15 m / 58x103 m2

Hinterburgseeli 1514 m a.s.l. / 11 m / 45x103 m2

(Schwarzsee 1046 m a.s.l. / 10 m / 455x103 m2 )

Burgseewli 613 m a.s.l. / 19 m / 53x103 m2

Impact of climate change on water quality

Lakes- Impacts of increased water temperatures in the epilimnion- Cyanobacterial blooms (potentially toxic)- Impacts of a longer stratification period and a shorter period of circulation on oxygen and nutrient concentrations- Impacts of shifts in the timing of physical and biological events - match/mismatch

Rivers- Impacts of increased water temperatures on fish habitat- Impacts of a reduction in residual water flow on biota- Impacts of an increased proportion of waste water during dry periods- Cooling problems for large industrial complexes

Groundwater- Impacts of a sinking groundwater table on geogenic contamination (e.g., summer of 2003)- Increase in nutrient concentrations (e.g. nitrate)- Changing redox conditions due to higher temperatures- “WRQ maps” for climate change in Switzerland

International cooperation

For example, cooperating internationally in deploying high-resolution ‘clever’ monitoring involvement on a global scale, e.g. within the expanding international network GLEON...

The Global Lake Ecological Observatory Network

(GLEON)• A grassroots network of– ecologists, engineers, information technology experts

– institutions and programs– instruments– data

• Linked by a common cyberinfrastructure• With a goal of understanding lake dynamics at local, regional, continental, and global scales

Yuan Yang Lake, Taiwan ; photo by Matt Van de Bogert

gleon.org

the eawag workshop on climate and water preliminary summary of results and implications for bundling...

Documents