A number of readily accessed, readily scanned, and easily comprehended Climate Change Power Point Lectures are available which point to the urgent need to reduce atmospheric CO2 from the current ~390 ppm to ~300 ppm.
Thus that by NASA's Dr Hansen entitled “Global warming 20 years later: tipping points near” (2008) (address to National Press Club, and House Select Committee on Energy Independence & Global warming, Washington DC [44 pages]: http://www.columbia.edu/~jeh1/2008/TippingPointsNear_20080623.pdf )
spells out that 300-325 ppm atmospheric CO2 concentration is needed for restoration of sea ice, QUOTES: "Target CO2: <350 ppm To preserve creation, the planet on which civilization developed" and "Arctic Sea Ice Criterion. 1. Restore Planetary Energy Balance -> CO2: 385 ppm -> 325-355 ppm. 2. Restore Sea Ice: Aim for - 0.5 W/m2, CO2: 385 -> 300-325 ppm. Range based on uncertainty in present planetary energy imbalance (between 0.5 and 1 W/m2)".
These excellent power point lectures on climate change are accessible via the links provided below.
Professor Barry Brook (Sir Hubert Wilkins Chair of Climate Change, University of Adelaide, Adelaide, South Australia), “Mitigation and Adaptation Strategies” (2008), an outline of paleoclimate history, climatic disruption and mitigation and adaptation strategies [40 pages]: http://www.lga.sa.gov.au/webdata/resources/files/Professor_Barry_Brook_-_2008_Climate_Change_Summit_-_PowerPoint_Presentation.pdf .
Dr Andrew Glikson (Earth and paleoclimate scientist, School of Archaeology and Anthropology & Research School of Earth Science, Australian National University (ANU), Canberra, Australia), "Human evolution and the atmosphere: return of the Pliocene?" (2008), illustrating the global temperature, methane and CO2 levels in the generally cooling period since the Pliocene (3 Mya, million years ago) during which time the genus Homo evolved to yield Homo sapiens (us) about 100,000 years ago. However, massive man-made greenhouse gas (GHG) pollution in the industrial era (post-1750) has pushed atmospheric CO2 concentration outside the range of 180-300 ppm obtaining during the final evolution of Homo sapiens from his immediate precursors over the last 600,000 years [46 pages]: http://sites.google.com/site/yarravalleyclimateactiongroup/dr-andrew-glikson-human-evolution-and-the-atmosphere-return-to-the-pliocene .
Dr James Hansen (top US climate scientist; Director, NASA Goddard Institute for Space Studies; Adjunct Professor, Columbia University, New York; member of the prestigious US National Academy of Sciences; 2007 Award for Scientific Freedom and Responsibility of the prestigious American Association for the Advancement of Science), “Global warming 20 years later: tipping points near” (2008) - address to National Press Club, and House Select Committee on Energy Independence & Global warming, Washington DC [44 pages]: http://www.columbia.edu/~jeh1/2008/TippingPointsNear_20080623.pdf .
Dr James Hansen (top US climate scientist; Director, NASA Goddard Institute for Space Studies; Adjunct Professor, Columbia University, New York), “Climate threat to the planet. Implications for energy policy and intergenerational justice”, Bjerknes Lecture, American Biophysical Union, San Francisco, California, 17 December, 2008 [39 pages]: http://www.columbia.edu/~jeh1/ .
[For a series of other incisive writings by Dr James Hansen see: http://www.columbia.edu/~jeh1/ , most notably Dr James Hansen, “Carbon Tax and 100% Dividend vs. Tax and Trade”, Committee on Ways & Means, US House of Representatives, February 2009: http://www.columbia.edu/~jeh1/mailings/2009/20090226_WaysAndMeans.pdf ].
Professor John Holdren (Professor of Environmental Policy and Professor of Earth and Planetary Sciences, Harvard University; Director, Woods Hole Research Center; former president, American Association for the Advancement of Science, AAAS; President Barack Obama’s chief science adviser), “The Science of Climate Disruption” (2008) – a summary of the basis of man-made global warming and the climatic disruption that has already occurred [32 pages]: http://www.usclimateaction.org/userfiles/JohnHoldren.pdf .
Dr Graeme Pearman (former CSIRO Climate director; GP Consulting; interim director, MSI; Monash University Sustainability Group), “Climate change: the evidence, science and current projections” (2008) [37 pages]: http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0011/126569/graeme-pearman-monash-university-namoi-climate-change-forums.pdf .
Dr Peter Seligman (Bionic Ear engineer, Cochlear and Monash University, Melbourne, Australia), “Bang for Buck in CO2 abatement” (2008) discusses where you can invest your money most effectively to reduce your Greenhouse Gas (GHG) emissions; some of our favourite solutions do not bear up under his analysis [43 pages]: http://sites.google.com/site/yarravalleyclimateactiongroup/dr-peter-seligman-the-bang-for-buck-approach-to-co2-abatement .
David Spratt and Phillip Sutton, Climate Emergency Network, “A Safe Climate Future”, (2008), based on the book “Climate Code Red. The case for emergency action” by David Spratt and Phillip Sutton (Scribe, Melbourne, 2008: http://www.climatecodered.net/ ), a powerful summary of the latest climate science results by 2 leading non-scientist climate activists heavily informed by top climate scientists such as NASA’s Dr James Hansen who indeed endorsed “Climate Code Red” as “a compelling case … we face a climate emergency” [95 pages]: http://www.climateemergencynetwork.org/images/stories/cen/ccr_pp.pdf .
All of the above are referred to by Dr Gideon Polya (biochemist, teacher, La Trobe University and U3A, Melbourne), “Global Warming, Climate Emergency Course” (2009), detailed course notes for an 8 x 2 hour course for the Yarra Valley University of the Third Age (U3A) on global warming, the present climatic disruption and what we can do about it [Semester 2, St. Andrew’s Hall, Rosanna, Melbourne, 1.30-3.30 pm, each Tuesday, 7 July 2009 onwards; one semester course attendance cost A$15 for non-U3A members, A$7.50 for members of another U3A branch; downloading lecture notes: FREE ] – 52 pages of carefully documented notes: http://sites.google.com/site/yarravalleyclimateactiongroup/global-warming--global-emergency-course .