1. Defining the present climate: Why does it matter? What help exists? Pandora Hope (BMRC) and Ian Foster (DAWA) Acknowledgements: Colin Terry (Water Corp), Andrew Watkins (NCC), Jay Lawrimore (NCDC), Lynda Chambers (BMRC), Peter Powers (BMRC)

2. Outline ‘Standard’ meteorological climatology Observed Trends and Breakpoints Examples of the issues and responses in various sectors Available help

3. Defining the present climate 1961-1990 http://www.bom.gov.au/silo/products/cli_chg/

4. Defining the present climate 1961-1990 http://www.bom.gov.au/silo/products/cli_chg/

5. Trends – A reason to change the ‘baseline’ definition? Combined global land-surface air and sea surface temperatures (degrees Centigrade) 1861 to 1998, relative to 1961 to1990; University of East Anglia, UK http://www.grida.no/climate/vital/17.htm

6. http://lwf.ncdc.noaa.gov/oa/climate/research/trends.html

7. National Climatic Data Center http://lwf.ncdc.noaa.gov/oa/climate/research/trends.htm l

8. National Climate Centre, Australian Bureau of Meteorology http://www.bom.gov.au/silo/products/cli_chg/

9. Annual Temperature SWWA Created using “Diagnose”

10. Summer Temperature SWWA

11. Early Winter Temperature SWWA

12. http://www.grida.no/climate/vital/18.htm

13. National Climate Centre, Australian Bureau of Meteorology http://www.bom.gov.au/silo/products/cli_chg/

14. Seasonality of SWWA Rainfall Decrease

15. Early Winter SWWA Rainfall Break-point in time series at 1968/69 NB: IOCI in general uses a breakpoint of 1975/76, which is the breakpoint of the sea-level pressure data in the region

16. Changes to the ‘baseline’ WMO suggested 1971-2000, but this was not adopted Some agencies are using the full period, e.g. NCDC uses 1880-2004 Many sectors use the time-period most relevant to their purpose

17. Major System Impacts http://www.watercorporation.com.au/ Integrated water supply scheme – source development plan 2001 had 2nd worst inflow to Perth dams 8 year sequence of lowered streamflow to 2005

18. Changes to Streamflow Probability 177 GL is the mean over 1975-96

19. Response of Water Corp. Major desalination of seawater Recycling of treated wastewater Better management of dam catchments to improve inflows Trading for water from irrigation cooperatives

20. Salt risk and land-use NB: This is an example only. The data is from station data interpolated onto a grid (Jones and Weymouth 1997). There will be differences from maps produced using other methods of interpolation 1950-19791980-2004 < 900 mm 900-1100 mm > 1100 mm 900-1100 mm Forestry, Mining Isohyet limits from Colin Terry, maps plotted using NCC gridded rainfall data by Pandora Hope

21. System Response - Waterlogging Frequency

22. Wheat Yield Trend Source: ABS state averages

23. Agricultural Responses Fewer very wet years may have affected rates of salinity spread Sowing opportunities tend to occur later Decreased waterlogging in susceptible areas. This may have improved conditions for cropping in higher rainfall areas Technology changes have improved productivity despite generally drier years

24. Tools available http://www.bom.gov.au/silo/products/cli_chg/ Australian Rainman (QDNR, BoM et al) DIAGNOSE; CD or website (v. large): ftp://ftp.bom.gov.au/anon/home/bmrc/perm/append/install_v3/ MetAccess (CSIRO et al) Climate Calculator – Dept Ag Future projections – IOCI, CSIRO

25. Conclusions There have been strong trends in rainfall in Western Australia, causing sectors to re- examine the climate ‘baseline’ Impacts have been strong in some sectors, and variable in others There is a range of tools that can help define climatology, opportunities and risks.

26. Climate Calculator – DAWA Risk Charts

27. Agriculture - Altered rainfall pattern