The Shocking Truth: The Scientific American Poll on Climate Change

There is simply no other explanation than nature absorbs about 1/2 of what man generates.

That might be true if man were the only generator of CO2. Consider this alternative hypothesis.

The earth gradually warms because of a more active sun. That temperature rise affects some of the natural processes that absorb or desorb CO2. Higher water temperatures at the sea surface near the equator could well increase the rate at which CO2 is released from the sea while warmer sea temperatures at near the poles cause less CO2 to be absorbed by the ocean.

That has been proposed as a mechanism to explain why CO2 peaks in ice cores follow temperature peaks by many hundreds of years. Dissolved CO2 is transported from cold waters near the poles to equatorial waters by very slow deep water currents that take hundreds of years to go the distance.

In such a case CO2 levels are not the driver of global temperature but the result of fluctuating global temperatures, and imbalance in CO2 absorption/desorption rates would be the norm for much of the time.

There could be other mechanisms at play here that also affect CO2 absorption and desorption. Perhaps higher temperatures cause CO2 to be released by clathrate structures (hydrates) in the seafloor sediments or in similar clathrates on land in cold regions. This greater release of CO2 could greater than the sea and the flora can absorb, so the CO2 levels go up in the atmosphere.

Over the longer run, you are right, the oceans will absorb and release CO2 according to their temperature. However the effect is small. Consider the changes in sea surface temperatures http://www.drroyspencer.com/2010/07/global-sea-surface-temperature-update-the-cooling-continues/. We would be seeing a large drop in CO2 because a cooler sea surface would absorb the CO2. To some extent it is true

there is a small downward blip in CO2 in 2008 with cooler SST when adjusted for seasonal variations. But note that the biggest seasonal factor is vegetation not SST. The northern hemisphere has a lot of land area with vegetation absorbing CO2 from spring through fall. Not so in the SH.

It appears that there is a small effect on the amplitude of the annual change in CO2. The 2008 amplitude (difference between high and low of the annual CO2 levels) centered around 2008. You can see the effect if you put a ruler connecting the highest annual CO2 peaks and repeat that for the lowest CO2 minimums.

The deep water ocean currents take hundreds of years to transfer CO2 from the downwelling surfaces near the poles to the upwelling surfaces near the equator. We could be now seeing the effect of enhanced CO2 absorption during the little ice age. The amount of desorption occurring at the upwelling surfaces depends on how much CO2 is upwelling as well as the temperature.

In other words, waters that contain greater amounts of dissolved CO2 than average are now surfacing. The surface temperatures at the downwelling areas are warmer now than what they were when the present upwelling currents received their load of CO2 hundreds of years ago.

The temperatures at the downwelling and upwelling areas are probably what control the mechanism I mentioned. Since the temperature in the plot shown in your link is for global sea temperatures, I don’t know for sure what the upwelling and downwelling temperatures are.

Yes, a very good point, the ocean buries the CO2 or releases it depending on the polar temperatures and particular the melt and refreeze. It is the refreezing itself that causes the downwelling since the remaining water becomes more saline and heavier and sinks to the bottom. But one mitigating factor is that the ocean turnover rate is very slow and so the sequestration of CO2 is very slow (or that's what the catastrophists would like us to believe). Second, the global SST which I linked to is much more important to the immediate absorption of CO2. But again, not so important that it has any kind of overwhelming effect.

The 2008 dip is very real but pales in comparison to the annual rise and fall of CO2. That implies that vegetation is much more important than SST over the short run. That suggests fossil fuels are too (over the short run). Your sequester/release mechanism is viable over the long run but would require extremely rich-in-CO2 upwelling areas to be a factor in the short run. I do not recall reading anything about such areas in the present oceans, but I have not read a lot in that area.

If the sea surface temperature changes due to whatever cause (sun variability, El Nino/La Nina phenomena, etc.), the difference between the absorbed and desorbed amounts of CO2 will change. Those differences will affect CO2 concentrations in the atmosphere.

Assume for a moment, the downwelling surface water temperature is 0 degrees C and the upwelling surface water temperature is 30 degrees C. By my rough calculations of the slopes of the absorption curve, if both SSTs are heated by a degree due to solar heating, then absorption drops by about 3.7%, while desorption increases by about 2.6%. If the downwelling sea surface temperature remains relatively constant because, as you say, it is a phenomena driven by the freezing of water and increased salinity, and if the geographical area where the downwelling resulting from this phenomena stays the same, then the amount of CO2 absorbed stays about the same, while the amount desorbed at the equator increases by about 2.6% if temperature there goes up by one degree C.

Downwelling might be caused by the fact that cold water is denser than warm water. I haven't compared salinity driven downwelling to temperature driven downwelling so I'm not positive which driving force is greater.

The point is that substantial changes in the difference between the amount of absorbed and desorbed CO2 can be caused by changes in the SST. Remember too that it takes hundreds of years, perhaps over a thousand years, for CO2 absorbed at the poles to be released at the equator. If so, temperature conditions at the poles a thousand years ago may determine how much CO2 is in the upwelling currents.

An article on this can be found here Link. It is not peer reviewed, so some caution may be needed. However, I have seen some poor papers in other areas of science get published because peer review on those papers was apparently poor or perhaps submitted to reviewers favorable to one side of a scientific controversy or perhaps to reviewers who do not have access to the data to rigorously check claims.

I suspect the annual cycles in CO2 correspond with the growing season or seasonal output of CO2. The great bulk of CO2 resides in the oceans, some 93% of it. The amount of difference between oceanic absorption and desorption is not insignificant, and the growth of CO2 in the atmosphere may well be controlled by it.

I'm going to bed. zzzz

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