WG1 glossary) defines radiative forcing as the change relative to the year 1750. This is also noted in footnote 2 of the SPM when the concept of radiative forcing is introduced. Using the logarithmic formula to account for the diminishing effect of additional CO2, =log(378/280)/log(360/280) in a spreadsheet, gives a 1.194 multiplier from 1995 to 2005, i.e. a 19.4% increase. This does not depend on the value of the climate sensitivity. The same result is obtained with any of Plimer’s 3 values (0.35◦C from figure 50, the 0.5◦C that he asserts without citation, or the 1.5◦C to 1.6◦C from the long-term historical data that he cites, e.g. item 104). ( value of 20% is obtained if the 1750 concentration is taken as 282 ppm.) — [also in TL list].
1 0 1 . p . 4 2 5 : I P C C d o e s n o t a c k n o w l e d g e t h a t C O 2 d e r i v e d f r o m h u m a n a c t i v i t y p r o d u c e s 0 . 1 of global warming.22 Using Plimer’s preferred (but unrealistically low) climate sensitivity of 0.5◦C, typing =1.44*0.5*LN(385/280)*1000 into a spreadsheet gives a warming of 229◦C, implying that without human and natural greenhouse gases, the temperature of the earth would be like that of the outer planets. Using the empirical (but still unrealistically low) estimate of 1.5◦C quoted by Plimer on page 426 would imply that without human and natural greenhouse gases, the temperature of the Earth would be below the physical limit of absolute zero. %
C O 2
atmosphere was higher than the pre-industrial revolution figure of 270 ppmv.2134 This is ‘cherry-picking’ from two different estimates of the Vostok dating. ccording to refer- ence 2134 (published in 1990), 140,000 years ago, the CO2 concentration was around 270 ppm, but the world was no longer in an ice age. ccording to more recent dating23, 140,000 years ago CO2 was below 200 ppm and significant warming did not begin until
about 500 years later
1 0 3 . p . 4 2 5 : T h e c u r r e n t C O 2 c o n t e n t o f t h e a t m o s p h e r e i s t h e l o w e s t i t h a s b e e n f o r t h o u s a n d of millions of years, .. which is clearly inconsistent with noting a current concentration around 385 ppm and many occasions noted by Plimer (e.g. on page 278) with CO2 around 180 ppm within the last million years. s
1 0 4 . p . 4 2 6 : T h e v a r i a t i o n i n C O 2 s h o w s t h a t a c l i m a t e s e n s i t i v i t y o f g r e a t e r t h a n 1 . 5 ◦ C h probably been a robust feature of the Earth’s climate system for over 420 million years. This is a repeat of the statement on p. 87 (citing the same reference, [Royer et al., 2007] as reference 2140) and contradicts his frequent undocumented assertion [items 69, 73, 120] that the climate sensitivity is 0.5◦C. a s
105. p. 430: If we drive a diesel car with an efficiency of 5.5 litres per 100 km then the daily greenhouse effect of one cow is equivalent to driving 10,000 km in this car. Well actually no — one cow (150 to 250 litres of methane gas per day) is the equivalent of 14 to 23 km driving — out by a factor of 400 or more. — [C ].
The summary in versions up to 1.5 incorrectly gave Plimer’s number as 1%. Using the dataset described on page 48.