1. Climate and weather Climate is the general or average weather conditions of a certain region. American Heritage Science Dictionary (2002) Climate is what you expect; weather is what you get. Heinlein: Notebooks of Lazarus Long (1978) Climate is the distribution of weather. AMSTAT News (June 2010)

2. Intergovernmental Panel on Climate Change Products Assessments Special reports Climate data Structure Three working groups Science Effects Mitigation Task forces Data and scenarios Greenhouse gas inventories

3. IPCC working group I Bureau: 8 members 2 co-chairs 6 vice chairs Fifth Assessment Report WG I 14 chapters 1500 pages 1000 nominations from 63 countries 29 coordinating lead authors 179 lead authors (2 statisticians–Claudia Tebaldi, David Stephenson) Assessment of existing research One statistician– Francis Zwiers

4. The assessment process

5. Confidence (qualitative – measure of validity of a finding, based on type, amount, quality and consistency of evidence) Uncertainty treatment and language in the IPCC report Likelihood (quantitative – measure of uncertainty in a finding, expressed probabilistically, based on statistical analysis of observations and/or model output and expert judgment)

6. Temperature measurements

7. IPCC on global temperaure

8. What is global annual mean temperature? Mean daily temperature e.g. average of min and max daily Mean annual temperature Average of daily means Mean global temperature Average over all locations

9. Measuring temperature

11. Stockholm data issues Location was moved twice (1875, 1960) Calibration (1826: 0 reads as +0.75; 1858,1915; annual thereafter)

12. Homogenization miscalibrated thermometer urbanization screen painted white?summertime correction

13. Heat island effect Country 21-24° City 32-38°

14. Some more data This is one day over central Europe. Over 160 years about 20 000 000 observations. And this is a small subset of the data!

15. Northern hemisphere temperatures

16. Global Historical Climatology Network

17. Historical SST data issues Ocean surface temperatureOcean surface temperature record Data from buoys, ships, satellites, floats

18. Ocean temperatures ICOADS 2°x2° since 1800

19. Comparison with other estimates

20. Sources of uncertainty Measuring local temperature Global temperature Number of stations Ocean temperature

21. The fit of models Climate is the distribution of weather To reasonably estimate a distribution (from data or from models) need a relatively long stretch of data–WMO suggests at least 30 years How well does the CMIP5 experiment used in the recent assessment work for describing global mean temperature?

22. Comparing models to data

23. Comparing global climate models to data

24. 30-year distributions

25. Comparing location and spread Shift function Δ(X ) X+Δ(X) ~ Y Location-scale is straight line Location horizontal

26. Sea level rise

27. Olympia hit with high tide and a storm

28. Measuring tides Connected to sea in bottom of well. Eliminates wave action and enables measurement under ice. A GPS measures station altitude.

29. Tides in Olympia

30. Tide gauges globally

31. Measurements

32. Why do sea levels rise? Water expands when heated Glacial and other land ice melt Measurement errors: Glacial readjustment Satellite drift Instrument drift

33. Available data for sea level projections Temperature projections from global climate models Use to project global sea level Tide gauge series from Seattle Use to project Seattle sea level rise Short tide gauge series from Olympia Use to relate to Seattle projections

34. Downscaling Find a statistical relationship between global sea level change and local sea level change In the case of Olympia need to also find one between Olympia and Seattle Apply this relationship to global sea levels estimated from projected temperatures Uncertainties?

35. Simultaneous confidence bands 2100 CI (38-56) w/res (52-80) AR5 (33-68)

36. Predicting 2075 Olympia sea level rise

38. Comparing the scenarios

39. How long will sea level rise stay below...

40. Various consequences 15 cm (0.5 ft) marine seawater infiltrate stormwater pipes at two highest tides. Temporary flooding. 30 cm (1 ft) stormwater pipes inundated. Larger and longer flooding. 75 cm (2.5 ft) Budd inlet overflows its banks. Wastewater contamination.