That indicates that the warming could have caused at most about 3 ppmv of the measured 95 ppmv CO2 increase.
(part 2 of 2)
30:00 this part started out okay.
It is true that it is the high-frequency transients that are damped by diffusion. But at 30:32 he said "low frequencies, long time scales... are strongly non-conservative" (and he said it again 2 minutes later). There's no basis for that.
36:00 "The human source is of order 5" [GtC]
That's what it was back in 1977. In 2014 it was about twice that. Ref: https://cdiac.ess-dive.lbl.gov/ftp/ndp030/global.1751_2014.ems
(But at 40:38 he shows a graph with approximately correct figures.)
36:25 "It's approximately balanced by native sinks, which absorb about as much -- the key word: approximately. Because native sources and sinks are two orders of magnitude stronger..." [that's a bit of an exaggeration!] "...even a minor imbalance can overshadow the human source."
That would be true were it not for the fact that powerful negative feedback mechanisms work to correct such imbalances.
37:00 "...human emission... accounts for only 4% of the total."
That's about right. But that's a lot!
37:20 "Global observations of surface flux... do not exist."
Actually, we do have some satellite measurements of that, now, though they're rough.https://www.nasa.gov/mission_pages/oco2/index.html
38:09 "Net emissions is just the sum of all sources minus the sum of all sinks. It determines the growth rate of global mean CO2."
40:00 "net global emission... varies between years dramatically... do I need to tell you that human emission doesn't do anything like this?"
Irrelevant. Transient perturbations like ENSO, major volcanoes, droughts, etc. cause fluctuations. How is that interesting or surprising?
40:54 "Net global emission evolves independently of the human contribution."
Completely wrong. The human signal is VERY apparent. If there were no human influence, you'd see net global emission fluctuating around zero: sometimes positive, and sometimes negative. But because of the large human input, net global emission has been positive every single year for at least sixty years.
42:40 "...accounting for nearly all of the history of net global emission."
Wrong. Temperature variation accounts for most of the small fluctuations in CO2 level, but almost none of the long-term trend over the 60 year measurement record.
45:00 "...human sources of methane are independent of human sources of CO2..."
Not really true. E.g., flaring natural gas prevents the emission of methane, and emits CO2, instead.
Additionally, methane released into the atmosphere has an average residence time of only about a decade, before it oxidizes into CO2 and water. So emitting methane now produces CO2 eventually.
45:15 "...unless you believe combustion stimulates bovine flatulence."
Cute. But, actually, energy from fossil fuels makes people much more prosperous than they otherwise could be, and prosperity enables people to afford luxuries... like cows.
45:42 "...surface properties account for most of the history of methane..."
Wrong. Just like with CO2, the fact that short-term fluctuations are largely explained by temperatures says nothing about the cause of the long-term trend.
46:42 "In blue is the induced component of CO2. It's determined entirely by surface properties."
...while showing a graph of MEASURED CO2 level (rising due to anthropogenic emissions)!
49:57 "Let there be no ambiguity... the black curve is just the integral of temperature, scaled by the observed sensitivity of CO2 emission."
Complete nonsense. He'd have you believe that the anthropogenic CO2 just vanishes from the atmosphere, and that CO2 level is increasing by more than 2 ppmv each year simply because global mean temperatures are now about 1°C warmer than they were during the Little Ice Age.
Why is nobody in that room laughing?
56:17 "To maintain equilibrium, the surface must therefore also transfer heat away mechanically, through conduction, and convection."
And evaporation. The water cycle is the most important mechanism which cools the surface of the earth. Evaporating water absorbs latent heat at the surface, and transports that heat from the surface to the mid-troposphere, where the water vapor condenses.
58:08 "...the mean is free of decadal variability... it follows that on those timescales the models have no predictive skill."
58:26 "Notice, this is the same timescale responsible for almost all the 20th century warming."
That's gibberish. Timescales aren't responsible for warming.
The fact that there are decadal scale fluctuations in temperature that exceed the long-term trend doesn't mean those fluctuations are "responsible for" the long term trend. It just means that there are many factors that affect measured temperatures.
59:00 He should be graphing CO2 on a log scale, because the warming effect of additional CO2 is logarithmically diminishing.
Even so, he's right that the GCMs (models) are not skillful.
1:03:00 "CO2 tracks the integral of temperature."
Complete nonsense. "Integral of temperature" is not even a meaningful quantity.
1. Dr. Murry Salby is one of several people who claim that the reason atmospheric CO2 levels are rising is not because
of mankind's CO2 emissions, but, rather, because the oceans are outgassing CO2, because of global warming.
They are wrong.
2. The most thorough examination of the cause of rising CO2 concentration which I've found is
this very clear and comprehensive analysis,
by Ferdinand Engelbeen. ↑