Yes., within other interglacial periods of the last 500,000 years do have a increase in co2 with them as the worlds warm and the oceans release co2. But only of 300-320 from 210-250 within the peaks of the ice ages to the peak of the interglacial periods.
For your other question above: Yes, but 50/1 is the ability as a whole to take up co2. But with a warming ocean that can take up less and releases a higher percentage of that.. Wouldn't it mean more Atmospheric co2. Remember the extra co2 we're adding is not a big number and so most of the co2 is in fact being removed, but what we're seeing as a increase is just the imbalance.
Before the IPCC announced that atm CO2 remained for ~100 years, research said atm CO2 was recycled every ~10 years. If the shorter term is correct that doesn't leave much time for an imbalance to accumulate.
As far as ice cores to approximate temps and CO2 level- I think they are useful but it is very problematic to compare them to actual direct measurements. The treering data used in preparing the Hockey Stick is a case in point. The proxies were only sensible to the 60's so the later data was discarded, leaving people with the impression that the figures were much more reliable than they are.
What I was stating is that you have a level of co2 being absorbed into the oceans, which maybe 50/1 rate, but the imbalance comes from, 1# more being put into the Atmosphere over a short time scale, which adds a good 100 ppm that other wise would be within the earth within oil shale, ect and 2# warming oceans cause this to slow down even more...Which increases our imbalance. Case and point the co2 may not have a very long time within the Atmosphere, but remember the carbon cycle is a "cycle" it's not only gets absorbed, but goes back into the Atmosphere and so as the oceans warm the oceans ability lowers to absorb carbon becomes less and it releases more of it. If the oceans got colder then the opposite would happen...Yes over time this would balance its self out and likely within a hundred or so years if we switched over to things like Nuclear, which has very little co2 output would start going down.
The climate system is not use to 390 ppm at least not the one that we have grown to love.
This shows that only 3 periods of the last 650 thousand years where the only times to get above 300 ppm. What these periods are the interglacial I was talking about above with the oceans ability to hold onto the co2 as they warm becomes less and releases it. I happen to find the increase of co2 very interesting because we're at a very high level that likely no human being has ever seen in the history of man. The fact that the peaks of co2 in the Atmosphere throughout the last million years happen ever warming of some sort is because of this. Co2 yes warms the planet, but it was very likely solar forcing that caused these other periods; not unlike the Holocene that we love now. But co2 also has the ability to warm if there is enough of it too and cause a warmer period then it might otherwise be.
The climate forcing of co2 is quite low when you think about it. Yes it might warm our planet some, but 4-5c like some believe is not going to happen in 90 years. Warming in the last 20 years has been around .14c to .17c per decade, which is pretty slow.
Decade Annual Rate of Increase (Atmospheric CO2)
2000 – 2009 1.92 ppm
1990 – 1999 1.52 ppm
1980 – 1989 1.61 ppm
1970 – 1979 1.22 ppm
1960 – 1969 0.86 ppm
So lets say F(x)=1.92(x)+389ppm
So this tells us if things remain the same each year will hit 400 ppm around 5.5 years and we will get to 450ppm around 32 years or 2042...Doubling at 89 years from the 280 ppm in 1800 at 560 ppm, which will be 2099. Of course this is more likely to get to this level much faster as this is increasing in its rate.
So a
linear increase would cause doubling by 2099. But the truth is a doubling don't have the effect that the hypers believe because co2 has a far lower warming effect on earth...More like 1-1.5c warming by 2100 for that doubling. Which would be good for plant growth and good for humans. More growable lands within Russia, Canada for one. The forcing is has got to be below 2.5 as far as I can see, which is why warming as been so much slower then they expected it to be. They where thinking 3.5-4.5 like forcing for people like Hansen. Also you have lower solar output too.
I agree with you about the ice cores...
