1. EARTH’S CLIMATE PAST and FUTURE SECOND EDITION CHAPTER 17 Climatic Changes Since the 1800s WILLIAM F. RUDDIMAN © 2008 W. H. Freeman and Company

2. Major Concepts: warming planet! Sea level change since 1880 –Source of records –Corrections for isostatic effects –17 cm rise; 4 cm thermal expansion, 5 cm mountain glaciers, 2 cm Gr +AA Surface temperatures since 1900 –Complications: reliability of early measurements, urban heat island effect 100-3000 m ocean temperature change since 1945 –Heat stored is 10X more than in the atmosphere and provides evidence of persistent warming Mountain glaciers –99% retreated between 1900 and 1980, average retreat over a mile Ground temperature profiles show clear warming –Record integrates century-scale warming that has diffused into ground Satellite measurements –Arctic sea ice retreating –Greenland thinning, Antarctica more stable –Tropospheric warming agrees with ground measurements Natural variability since 1800’s? –Pacific decadal oscillation –North Atlantic Oscillation

4. What correction needs to be made for most of these records?

9. Corrected record

10. Ground T recording stations

11. Corrected for heat island effect

13. Mountain glaciers

14. Important study from 2005!

15. Once collect temperature profile, model required temperature change at surface with diffusion models

16. Satellite measurements of Arctic sea ice

17. Satellite measurements of NH snow cover

18. Satellite measurements of growing season in Alaska

19. Satellite measurements of ice sheet thickness important part of climate monitoring

20. NOAA NCDC http://www.ncdc.noaa.gov/faqs/climfaq14. htmlhttp://www.ncdc.noaa.gov/faqs/climfaq14. html

21. Table 17-1 (in cm) Ocean thermal expansion+4 Mountain glaciers+5 Greenland and Ant. Ice+2 All factors+11 Observed sea level rise+17

22. Short term oscillations? El Nino

23. Short term oscillations? Pacific Decadal Oscillation

24. Short term oscillations? North Atlantic Oscillation