http://www.pbs.org/wgbh/warming/debate/singer.html
http://www.skepticalscience.com/global-cooling-mid-20thcentury-advanced.htm
CE 401 http://www.hillsdale.edu/news/imprimis/archive/issue.asp
?year=2007&month=08
HW6
geologic past and evolution of climate change since the industrial revolution
3 February 2011 http://hockeyschtick.blogspot.
com
/2010/09/is-sun-causingglobal-warming.html
http://www.skepticalscience.co
m/solar-activity-sunspots-global-wa rming.htm
http://solar-center.stanford.edu/sun-on-eart h/glob-warm.html
www.realclimate.org
Robinson paper for HW6 http://www.independent.org/newsroom/article.asp?id=1945 couple of pdf’s on the HW website on solar stuff – read the Robinson article to page 8 and figure out what their arguments are, and then look around for support or nonsupport

HW 6 now due next Thursday quiz from last time:
• nearly everyone like the ppt style; more emphasis on the myriad of graphs of what is really important; I have been replacing the ppt on the web with the actual class one
• HW: some of the problems have not been clear as to what is expected and that has caused frustration ; do examples in class
• class interaction – I need to just keep pushing for more
• general thoughts – class will be graded on a curve; go over math more before HW;
TA office hours to twice/week; other resources
– use web

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

interesting new web site: http://carbontracker.noaa.gov.

360
N
2
O
CO
2
200
CH
4
The atmospheric concentration of CO
2
, N
2
O, and CH
4 now exceeds by far the natural range of the last 650,000 years - current changes have occurred all in a few hundreds of years
time (thousands of years before present)
note

Current level is higher than any time in past
600,000 years.
150,000 years ago to present

this graph  dramatic evidence that CO
2 drives climate: more CO
2
 higher temperatures. YES?
Here is Al Gore on this graph: “Here is an important point. If my classmate from 6 th grade were to see this, he would ask, “Did they ever fit together?”. The answer from the scientist would be, “Yes, they do fit together.” It’s a complicated relationship, but the most important part of it is this: When there is more CO
2 in the atmosphere, the temperature increases because more heat from the sun is trapped inside. There is not a single part of this graph – no fact, no date, or number – that is controversial in any way or is disputed by anyone.”
What is cause and effect? The implication here, honestly stated by Gore, but implied , is more CO
2
, higher T
Yet, many scientists think the opposite: large changes in CO
2 were a result of the warming, not the cause. Changes in temperature in this graph were driven not primarily by CO the Earth.
2 changes, but by changes in the orbit and axis of
Caillon et al, 2003, Science 299, 1728  CO
2
lags behind temperature changes by about
800 years + 200 years (why 800 years?)
Some climate scientists now doubt the order.
Richard Muller (Physics for Future Presidents, 2008) 
“The fairest statement that can be made is that the issue is unsettled”. “Many people see the plot and come away believing that CO
2 has been established as the main driver for past climate change. That is very likely a correct conclusion for small (1 ° C) changes attributed to the present
CO
2 increase, but not clear for the dramatic temperature variations of ancient data shown in the plot”

10 ° C
10 ° C
5 ° C
150 source: Jouzel et al. 1994
0
note how stable temperature has been for the last 10,000 yrs

Mann et al, 1998

2
2

Conclusions from the Climate Record preindustrial to 650k years ago (no human influence)
• temperatures have varied by approximately 7 ° C
• highest observed CO
2 is about 300 ppmv (current 385 ppmv)
• highest observed methane is about 0.7 ppmv (current 1.7 ppmv)
• temperature, CO
2 and methane follow each other closely in time
• changes have generally occurred over long time periods
• past 10K years have been remarkably stable in temperature
• this period marked the development of civilization
• most “equable” climate of the past many millions of years
• rapid (decadal) changes in surface temps of 5-6 ° C have occurred in the past

Global CO
2 distribution in ppm
WHY
380 parts / million
372 ppm

continuing now to the present
– the rest of the diagram shown earlier hockey stick plot

hockey stick:
• published in 1998
• NH remarkably constant showing cool years 1000-1900 with significant global warming occurred
• 2001 IPCC report included it – 5 times in the summary volume alone
• prominently featured in Al Gore’s film
• showed the modern fossil fuel era was unprecedented in increased temperature
• just like the CO
2 rise plot  patently obvious that humans were causing warming
• Canadian gov’t sent a copy to every household in Canada
• every politician in DC was familiar with it
• 14 th century COLD period appears nowhere in the plot (it was European only?), but that cold period is well established
• the graph is wrong – the analysis has proved to be faulty and really only represents western US, not the northern hemisphere
• US National Academy of Sciences was asked by Congress to review  confirmation of error
• does it matter that the hockey stick plot was wrong?
• yes, it reinforces misconceptions
• to a scientist, it is wrong, but it is just another step in the process
• IPCC consensus did not depend on the hockey stick graph of temperature vs time
• it is embarrassing for sure
• scientists usually reach the truth, but sometimes it takes a while

US surface temperature record

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

NASA Global Temperature Record 1880 - 2008 source: GISS, 2010
• 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

IPCC 2007

During the 1950s and 1960s, average global temperatures leveled off, as increases in aerosols from fossil fuels and other sources cooled the planet.
I will put the IPCC technical summary and frequently asked questions/answers onto the class website today