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GEOSS support for IPCC assessments: A workshop on the data needs of the climate impacts, adaptation and vulnerability research community, 1-4 February 2011, Room C1, WMO Building, Geneva.
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GEOSS support for IPCC assessments: A workshop on the data needs of the climate impacts, adaptation and vulnerability research community,1-4 February 2011, Room C1, WMO Building, Geneva （Lead Authors for the 4th Assessment Report of the IPCC, WG II, Chapter 3 “Freshwater resources and their management”） SESSION 3: WATER RESOURCES Past assessments and data sources Critical issues: gaps, shortcomings, coverage, scale and currency Taikan Oki Institute of Industrial Science, The University of Tokyo
WGIII WGII WGI (Richard H. Moss, et al., Nature, 2010)
AR4 Ch3: Key Uncertainties Quantitative projections of changes in hydrological characteristics for a drainage basin. Precipitation is not reliably simulated in present climate models. However, it is well established: precipitation variability increases useful conclusions are possible for snow-dominated basins Sea-level rise will extend areas of salinisation of groundwater and estuaries, resulting in a decrease in freshwater availability in coastal areas
AR4 Ch3: Demands improve the understanding of sources of uncertainty in order to improve the credibility of projections. scale mismatch between the large-scale climatic models and the catchment scale (down scaling) Impacts of changes in climate variability need to be integrated into impact modelling efforts. Improvements in coupling climate models with the land-use change, including vegetation change and anthropogenic activity such as irrigation
AR4 Ch3: Shortcomings Impacts on water quality and ground water Economic aspects of climate change impacts and adaptation options related to water resources Research into human-dimension indicators of climate change impacts on freshwater Impacts of climate change on aquatic ecosystems (temp., flow regimes, water levels, and ice cover) Detection and attribution of observed changes in freshwater resources, with particular reference to characteristics of extremes
AR4 Ch3: Observational Network Progress in research depends on improvements in data availability, calling for enhancement of monitoring endeavors worldwide, addressing the challenges posed by projected climate change to freshwater resources, and reversing the tendency of shrinking observation networks. Broadening access to available observation data is a prerequisite to improving understanding of the ongoing changes.
Global Can we attribute observed changes of global mean precipitation either over globe or land? Land only • Very short period, but we are measuring the drastic change?! • Large descripancies among GCMs areal and uniform observation is relevant for evaluation (Nohara et al., JHM, 2006)
AR4 Ch3: Data needs Relatively short hydrometric records can underplay the full extent of natural variability and confound detection studies, while long-term river flow reconstruction can place recent trends and extremes in a broader context. Data on water use, water quality, and sediment transport are even less readily available.
No “detection and attribution of climate change impacts” on freshwater resources, but “current vulnerability”
Limited number of quantitative messages on the future projections.
Total Water Withdrawal (106m3/y)in 2050 (difference to Year 2000) (2055-2000) A1b (Shen, et. al, 2008, HSJ)
Change in water stress index for 2050 (difference) 2055-2000 A1b A2 < -0.2 -0.2 ~ -0.1 -0.1 ~ 0.1 0.1 ~ 0.2 0.2 ~ 0.4 0.4 ~ 0.6 > 0.6 B1 MultiGCM/GSWP2
Change in water stress index for 2050 (ratio) 2055/2000 A1b A2 < 0.5 0.5 - 0.9 0.9 - 1.5 1.5 - 2.0 2.0 - 3.0 3.0 - 4.0 4.0 - 5.0 B1 > 5.0 MultiGCM/GSWP2
Social changes as well as climate changes should be considered.
Number of people underserious water stress Rws in 2055 (A2) Rws= (W-S)/Q Awc= Q/C (m3/y/c) (Oki and Kanae, Science, 2006)
Number of people could be fine, but economical value should also be quantified.
Impact Assessments with CC and SC More frequent with Climate Change Same magnitude of hazard will cause different damage How will it change with ΔT or GHG level?(mitigation) Additional Damage by CC How will it be changed by investments in adaptation? Current relationship rare &severe hazard Probability of Non-Exceedance
-mi -ad -mi +ad Climate change cost = mitigation cost + adaptation cost + residual damages +mi +ad +mi -ad (De Bruin et al. 2009)
Knowledge Gap? (De Bruin et al. 2009) Additional Cost (Damage) by Climate Change ($$) ?? Experts in disaster risk management is relevant for climate change policy studies!! Investment in Adaptation ($$)
One of new issues in AR5/WGII/Ch3 assessing the integrated impacts of climate change on water resources management through: hydrological changes, temperature rise, increments of CO2 concentration, sea level rise, and mitigation and adaptation measures, including the expansion of renewable energy consumption, together with non-climatic (socio-economic) changes.
Earth Observation (from space) for detections of long term trends and changes for early warning system: ( adaptation) Contribute for risk management. Numerical weather forecasts highly depend on satellite information. Precipitation obs. from space can contribute for issuing alerts in data poor regions. for seasonal predictions: ( adaptation) Utilize current states as for the initial conditions in predictions: SST, soil moisture, snow cover, vegetation cover, … for calibration, validation, and improvements of physically based numerical models future
Required data for “water” Historical record: stream flow, GW level, water use, … Field campaign data for model developments Atmospheric forcing: P, Rs↓, Rl ↓, T, q, u, ps, pCO2, … Detailed topography (in the future as well?!) and geology, … Land use/land cover, vegetation type/fraction, soil type, … Population, GDP, technology, … (from RCPs/SSPs) Irrigation efficiency, cropland area, irrigated area, crop type, crop calendar, agricultural skills, fertilizer input, … Reservoirs: location, capacity, operation rule, … Medium size reservoirs, small ponds/tank, rain harvesting, … Water related disaster database Floods, droughts, storm surge, land slides, …
For researchers outside GEO/IPCC Don’t Compare AO-GCM outputs with observations in daily, monthly, or even in annual time scale. (e.g., P on July 1st, 2008 by AO-GCM & Obs.) Use GCM outputs as if they are from in-situ observation: biases, different PDFs, … but Do Think how we can extract valuable information from GCM outputs signs of trends could be different among GCM estimates Business Chance in providing value-added data
Reminders • Detection and attribution of long-term trend in hydro-climatological “impacts” are as relevant as applying GCM predictions for the future. • Let’s consider social changes provided from SSPs (shared socio-economic pathways) in impact assessments. • with autonomous and planned adaptation • Hazard-damage relationships with adaptation measures should be investigated & developed. • Preferably with quantitative economic value ($$)
AR4 Chapter 3 Executive Summary The impacts of climate change on freshwater systems and their management are mainly due to the observed and projected increases in temperature, sea level and precipitation variability (very high confidence). Semi-arid and arid areas are particularly exposed to the impacts of climate change on freshwater (high confidence).
AR4 Chapter 3 Executive Summary Higher water temperatures, increased precipitation intensity, and longer periods of low flows exacerbate many forms of water pollution, with impacts on ecosystems, human health, water system reliability and operating costs (high confidence). Climate change affects the function and operation of existing water infrastructure as well as water management practices (very high confidence).
AR4 Chapter 3 Executive Summary Adaptation procedures and risk management practices for the water sector are being developed in some countries and regions (e.g., Caribbean, Canada, Australia, Netherlands, UK, USA, Germany) that have recognised projected hydrological changes with related uncertainties (very high confidence). The negative impacts of climate change on freshwater systems outweigh its benefits (high confidence).
