If the CO2 content is not well mixed, how come the entire atmosphere records the activities of the Northern boreal and temperate forests? CO2 decreasing in spring/early summer, increasing in the autumn and winter. Furthermore this signal spreads progressively southward with its amplitude gradually diminishing This is a definite indication of CO2 values varying globally without them being identical everywhere.

Will it? How can you be so sure of this? What if CO2 concentrations start to fall, before humans have managed to control themselves?

As with anything in the future, we can never be absolutely sure, but our understanding of the carbon cycle is that to get atmospheric concentrations to start decreasing would require getting anthropogenic emission to zero, or pretty close to zero. I can't think of an explanation for why it would start dropping if we didn't get emissions close to zero. On the other hand, there are carbon cycle feedbacks that mean that nature could become a net source. In this case, it is possible that we could stop emitting and atmospheric CO2 could continue increasing. However, this is regarded (as I understand it) as unlikely unless we were to emit an awful lot more than we already have (thousands of GtC).

Dung. I don't know anyone who has ever believed that CO2 is well mixed employing your type of definition (at all points on the planet at all times). After all it has long been known that the yearly temporal and spacial pattern of CO2 exists and Hawaii was deliberately chosen to be well away from human influences - in other words away from local inhomogenieties. My understanding (which could be wrong) is that the Earth's wind systems are efficient at eliminating these inhomogenieties, but that new ones are constantly forming. What this means is that a single molecule of CO2 can become mixed and end up anywhere in the atmosphere. I believe this conclusion was reached by the study of the spread of C14 after atmospheric nuclear tests.

Dung. Don't blame me for how other people use their terminology. C14 became evenly distributed throughout the atmosphere, therefore you can say it is well mixed. It implies that CO2 moves around the entire atmosphere. Unfortunately "well mixed" has got confused with "homogeneous" which clearly CO2 is not. Nevertheless, given that the major sources, sinks and fluxes of CO2 are in the northern parts of the Northern Hemisphere, the variation in CO2 is remarkably even, suggesting mixing processes are important.
If scientists thought CO2 was well mixed = homogeneous, why would they go to the trouble and expense of mapping this parameter from space?

Dung. I should have added :- ( or perhaps : -o
😈

Many thanks to all (including aTTP) for your contributions. I've enjoyed reading them all, but the aTTP/RR discussion has intrigued me.

aTTP says (and for what little it's worth, me not being a scientist, I'm inclined to agree):

"As with anything in the future, we can never be absolutely sure, but our understanding of the carbon cycle is that to get atmospheric concentrations to start decreasing would require getting anthropogenic emission to zero, or pretty close to zero. I can't think of an explanation for why it would start dropping if we didn't get emissions close to zero. On the other hand, there are carbon cycle feedbacks that mean that nature could become a net source. In this case, it is possible that we could stop emitting and atmospheric CO2 could continue increasing. "

But that still leaves open my earlier question of why are global CO2 levels apparently rising at a record rate when mankind's emissions have apparently stabilised?

I now see 3 possible answers (or a combination of all 3):

1. Mankind's emissions have not stabilised after all, and we are wrongly assuming that reported CO2 emissions from states around the world reflect reality - i.e. we wrongly assume that there is no under-reporting going on;

2. Martin A's possible explanation: "It is known that:
- Global temperature has risen
- Rate of CO2 emission from the land and ocean increases with temperature."

3. There may be other things going on naturally in the environment that we don't yet understand.

Personally, I'm going with a mix of all 3 explanations.

Whatever the truth, it still leaves the question of what are the implications for policy by way of response.

Mark,

But that still leaves open my earlier question of why are global CO2 levels apparently rising at a record rate when mankind's emissions have apparently stabilised?

aTTP

Thank you. I've bookmarked it and will read it at my leisure later. Comments to follow in due course, if I have any that may be relevant.

Life on Earth seems to prefer 400ppm to 300ppm, contrary to what Climate Scientists have been fearmongering about.

If they have been so wrong about 400ppm, why should anyone worry about 500ppm?

Once there is no Carbon Tax, or threat of Carbon Tax, there will be no need for Creative Carbon Tax Accountancy, or fraud as it is normally known. Mauna Loa etc can carry on measuring actual ppm, and nobody will bother to use computer models to "guesstimate" production of Carbon dioxide for economic gain.

I'm reasonably certain that the isotopic composition of atmospheric CO2 has not changed significantly in recent years - because otherwise we would have heard about it and there would have been multiple attempts to explain it, all pointing to human culpability. That being so, the various fluxes are probably the same, just their magnitude has changed. If the human flux of CO2 has stabilized (probably true; a huge amount of worldwide effort goes into those estimates), then some other, more "natural" pathway must have changed. If the Earth has greened, numerous fluxes will have altered. So a related question to Mark's is - why aren't we seeing the effect of the Earth's greening in the atmosphere, or are we but not identifying it?

A thought has just occurred. There's always war going on somewhere in the world. I assume that aircraft buzzing around dropping bombs (and possibly the act of bombing too) are emitting CO2. Buildings on fire, tanks burned, oil wells destroyed - all must emit CO2.

Is this accounted for in any way when countries provide their accounting of CO2 emissions to UNFCCC (or whoever is responsible for tallying it)?

Mark you are not challenging Gwendolyn's sinecure are you? After all, barrel bombs drop out of the sky by themselves. Assad is not going to assume that carbon footprint!

Mar 20, 2017 at 8:07 AM | Mark Hodgson

The biggest industrial expansion was during WW2. Quite a few bombs were dropped, lots of oil and coal was burned and large quantities ended up in the sea unburnt. Fire Brigades all over the World were quite busy.

Where does WW2 feature in graphs and statistics for CO2 and Global Warming? The coldest winter in living memory was 1947, followed by 1963.

The idea of tanks and warplanes being assessed prior to purchase based on their Green-ness and Carbon Emissions, is such a stupid and pointless idea, that I expect the UN are working on it.

Depleted Uranium Armour Piercing Shells being replaced by Depleted Composting Toilet Sewage Effluent Sludge "splat" rounds, could be a way of fertilising Middle Eastern deserts, and getting rid of EU/US Green Crap at the same time.

CO2 is quite well mixed. The global fluctuation according to Jaxa varies only a very small range of ppm at any given time. One must look beyond the color coding and instead read the scale the colors relate to. ATTP is still stuck, as are so many climate extremists, on stupid. Demanding that his views on CO2 be accepted as well as his policy demands. The fact that not one meaningful prediction of climate doom has been borne out in reality is lost on the extremists. It is as if they look at the color codes on graphs and maps and conclude red means crisis.

Dung JAXA satellite results map would never have provided evidence that human activities are a major cause of atmospheric CO2 levels. Human contributions were always identified as small relative to "natural" sources. The trick was to claim these sources were new and could unbalance a previous equilibrium.
The correlation between estimated human emissions of CO2 and atmospheric increases is near perfect (exceptionally high degree of correlation (9.97... if I recall correctly)) that I have never questioned the link , although I cannot counter Ron Spencer's counter argument.

GC

The British government already messes with issues like fuel for military aircraft, vehicles and ships (to the detriment of performance) in the name of sustainable development courtesy of Oliver Letwin.

Mar 20, 2017 at 11:41 AM | Dung

Can you imagine how an EU Defence Force would have worked, with French and German manufacturers fakilng emissions standards for Heat Seeking Missiles and battle tanks, invading other countries for excess use of barbecues in summer, or saunas in winter?