1. CE 401 Climate Change Science and Engineering evolution of climate change since the industrial revolution 9 February 2012 http://www.skepticalscience.com/global-cooling-mid- 20th-century-advanced.htm http://www.hillsdale.edu/news/imprimis/archive/iss ue.asp?year=2007&month=08 www.realclimate.org http://solar-center.stanford.edu/sun-on- earth/glob-warm.html http://hockeyschtick.blogspot.co m /2010/09/is-sun-causing-global- warming.html http://www.pbs.org/wgbh/warming/debate/singer.html

2. where are we in the syllabus: latest version always on website 

3. the global picture

4. Global CO 2 distribution in ppm 380 parts / million 372 ppm

5. last decade is the warmest decade on record increase in past 25 years is ~ 0.2°C/decade why the leveling off/cooling in the 50’s? – CO 2 record is very smooth – no big bumps and wiggles NASA Global Temperature Record 1880 - 2008 source: GISS, 2010

7. NASA Global SURFACE Temperature Record 1880 - 2008 source: GISS, 2010

8. surface temps are different than temps above the earth surface – where do satellites measure huge discussions about “where” to measure temp – stratosphere shows a cooling

9. altitude dependent weighting functions for satellite temp sensitivity

10. stratosphere mid troposphere lower troposphere actual surface temperature anomaly vs time 1960 – 2006 as obsv by satellite

11. What are some of the problems with these graphs of surface temperature vs time? There are lots of problems with these graphs!! name some

12. where is temperature data collected (geographic distribution) how is temperature collected? (same method everywhere?) what affects the reading of the thermometer? (surroundings) consistency of measurement method over a period of years

13. urban heat island effect California surface weather stations Robinson et al (2007): Surface temperature trends 1940-1996 from 107 measuring stations in 49 CA counties. Trends combined for counties of similar population. The “X” show the stations used by NASA GISS for their estimate of global surface temperatures. original source: F. Singer, Hot Talk, Cold Science, 1997 California weather stations

14. how would you go about quantifying the urban heat island effect? where are the urban areas?

17. source, J Geophys Res.,2003 current locations of global thermometers

18. NOAA  2010 tied 2005 as the hottest year on record

19. look at other data sets

20. sea surface temperature 1850 - 2004 source: IPCC 2007 what are potential problems with this graph? red = observations models

21. red: reconstructed sea level fields since 1870 (Church and White, 2006) blue: coastal tide measurements since 1950 (Holgate/Woodworth 2004) black: satellite altimetry (Leudiette et al, 2004) sea level change 1880 - 2004 source: IPCC 2007

22. Figure 5.1 0-700m layer. shading = 90% confidence. Global ocean heat content source: IPCC 2007

23. total column water vapor in %/decade monthly averages 1988 – 2004 over ocean

24. Snow cover and Arctic sea ice are decreasing (area vs time) Spring snow cover in millions of square km 1920 - present Arctic sea ice area decreased by 2.7% per decade 1979 - 2005 source: IPCC, 2007 glaciers are retreating

25. Glaciers and frozen ground are receding area of seasonally frozen ground in NH has decreased by 7% from 1901 to 2002 increased Glacier retreat since the early 1990s source: IPCC 2007

26. Palmer Drought Severity Index 1900 - 2002 source: IPCC, 2007

28. observations of measured change – IPCC 2007

29. detection of significant change is a statistical problem: finding a small signal in a sea of poorly understood noise the instrumental record is short --> rely on proxy measurements changes have obviously occurred over the past 100 years that are not human related if an observed change in the record is judged unlikely to have occurred due to natural processes --> implicates human factors (???) assignment of attribution to a human cause requires consideration and elimination of all plausible non-human mechanisms can’t eliminate all plausible mechanisms cause and effect are usually approached with a series of controlled experiments, but this cannot be done in this case experiment is not systematic - too many parameters are being changed at one time

30. Global Mean Temperatures Annual mean Smoothed series 5-95 decadal error bars source: IPCC = Intergovernmental Panel on Climate Change, 2007 11 of the past 12 years are the hottest on record

31. Hansen et al, 2001 – on class website now

32. % time during year when temps were below 10 th percentile for cold nights or above the 90 th percentile for warm nights: black 1901-1950, blue 1951-1978, orange 1979-2003