I was struck by the correlation to the temperature curves. To think you could be measuring CO2 on a mountain in Hawaii and come up with global temperature about as good as the satellites or ground stations was unexpected to me. I was interested in the chicken or egg problem of which comes first, temperature or CO2.

I did something else in this “analysis.” I simply added up the fossil fuel CO2 emissions and added the CO2 contributions from land use to get a curve of anthropogenic CO2. I then divided, year by year, the atmospheric CO2 (from 1850 to 2006) by the anthropogenic CO2. I think Dr. Keeling did this and came up with about 55% as a constant. A constant rate of residual CO2, in view of an increasing CO2 load, always fascinated me. My chart shows 40% to 1877, a jump up to 70% and steady decline to 1899, constant 50% to 1938, and a drop to 40% by 1952, and then flat to 2006.

I think these two curves are trying to tell me they are related by blood, not marriage.

My bias is that what global warming trends there are are probably not caused by CO2 changes. I think my position is reasonable as the burden is on the “sky is falling” position to be convincing. I, for one, am not convinced. In knowing this, I try to be extra careful in judging the other side’s arguments and try to keep my head above the sand.

Any ideas on the usefulness of these curves or how they are related?

[Response: Good question. The abstract of the Le Quere paper states that the cause of the reduction in CO2 uptake by the southern oceans is a human-induced change in wind patterns (I would presume that is a change in the Antarctic vortex, caused by ozone depletion) rather than CO2 saturation. Also, their stated reduction in CO2 uptake (0.08 petagrams/yr/decade) is not huge (but is certainly meaningful!).

The global CO2 contration has not shown statistically significant acceleration since about mid-2000, so I'm not ready to say it's definite. But it's possible, and given the trends not only in wind patterns but in temperature as well, it seems highly likely that the southern oceans will saturate in the near future.]

Considering that we have had 8 years of global cooling, 1998 being the hottest year on record, I’m not sure why it matters? Really, that does shoot down the CO2 causes Global Warming theory doesn’t it?

the Grit

[Response: We have most definitely *not* had 8 years of global cooling. We had global cooling 1998 to 1999, because of the end of the extremely strong 1997-1998 el Nino. Trend analysis shows that since 1999, global temperature has risen at a rate of 3.8 +/- 1.7 deg.C/century (and yes, that result is statistically significant).

Also, 1998 was the hottest year on record according to HadCRU, but according to GISS, the hottest year was 2005. According to either, the difference between 1998 and 2005 is not statistically significant.]

I would venture to say that the CO2 level measured at a place like mauna loa is almost certainly affected by winds (not only local ones but worldwide, since these determine overall mixing) and is always measuring a level that is indicative of emissions that occurred several months (if not a year or more) in the past.

Rather than evenly mixing the emissions, certain persistent wind patterns might actually tend to concentrate CO2 emissions over certain areas.

This may account for at least part of the increase during El nino.

CO2 may be “fairly well-mixed”, as some say, but the mixing takes some time and new emissions are always being added to the mix which are not registered immediately, at any rate.

[Response: Interesting thought. I'd suggest that most of the "1st residuals" are global rather than local to Mauna Loa, because the residuals from Mauna Loa and South Pole station match each other very closely. They do deviate, but not by more than 1 ppmv, and usually less than that.]

(Pacific) Ocean surface temperature?

Projecting a linear trend based on the 1975-2005 data suggests that we won’t reach 450 ppmv until after 2050. Projecting a 2nd-order polynomial trend based on the same period suggests that we’ll reach that level before 2040.

When thinking about mitigation, that extra decade makes a big difference.

graph:
http://home.casema.nl/errenwijlens/co2/co2lt_en.gif

[Response: The 3-rate model is a mathematical model for CO2 since 1997. It involves no assumptions or models relating to the physical cause of CO2 changes; it's just an approximation to the numerical signal.

And correlation is not causation; it seems to me far more likely that the (weak) correlation between lower troposphere temperature and CO2 growth rate since 2000 is not because lower troposphere temperature causes an increase in CO2 growth rate, but because they share a common root cause.]

while it is true, that most of the increase in CO2 is due to anthro CO2 (but se http://www.agu.org/pubs/crossref/2007/2006GL029019.shtml) or Tamino’s blog “CO2 surge”,
don’t forget, that the world is oversaturated with CO2 and even if we stop emitting now, the world would still warm around 0.6 Celsius. So the future warming will be faster, than the previous, as the climate is far from equilibium under *current* CO2 levels…

Not the best data but:

http://www.eia.doe.gov/pub/international/iealf/tableh1co2.xls

If you look, from 1980-84 (and IIRC as fas back as 1970) there is a slightly flat or even declining amount of fossil fuel burnt. This is followed by a sharp rise up to 1988-1989, followed by a basically flat picture until 1994. After that there is a general rise with breaks in 1997-98 and 2000-01; the very biggest increases are in 2002-03 and 03-04 (end of series) corresponding with huge rises in Chinese emissions.

Total emissions have only gone up around 50% in the whole time frame, whith most of that increase being post-1994. It would be interesting to graph this data against the above graphs..

I suspect that the good news here is that the recent increase in the rate of CO2 increase is man-made, and not a natural feedback. The bad news is that China has just overttaken the US in total emissions and shows no sign of slowing down.

[Response: Thanks for the data link. I've plotted the CO2 growth rate vs emissions in the UPDATE to this post.]