Atmospheric CO2.

By Pat Hackett

How much has CO2 risen in our atmosphere due to anthropogenic (the result of human activity) causes? This question is quite straightforward to arrive at a reasonable estimate but it is interesting to see the attempts to arrive at quite meaningless and far off estimates. This flawed method here is one by T.V. Segalstad who ignores the effects of fluxes of carbon between the oceans, biosphere and atmosphere when looking at carbon isotopes in the atmosphere.

However first some basic facts:- 

Changes in CO2 from preindustrial times to 2014.

Pre industrial CO2 levels had been relatively stable for several hundred years at around 280ppm and have risen since then to around 400ppm. Accurate measurements for over 50 years form sites such as Mauna Loa show the increases since 1956. (figure 1)

Figure 1:- Increase in CO2.

Figure 1 shows the net annual variation in CO2 due to exchange of CO2 between the atmosphere and mainly the biosphere which, over a single year, is much greater than the annual but steady increase in CO2 due to anthropogenic emissions. This annual cyclic variation can be attributed mainly to the growth and decay of organic matter in the Northern Hemisphere.

Unless volcanic activity has increased by something in the order of 50 fold, waiting for the industrial revolution to start doing so, it is reasonable to assume that the steady increase has been due to anthropogenic causes. 120ppm out of 400ppm represents 30% due to anthropogenic causes

.

How can a reasonable estimate of around 30% be changed to a range of estimates from somewhere between 0 and 4%? You may stumble across statements like this in some web sites.

Here is a link that deals with the following issue:- The Amount of Non-Fossil-Fuel CO2 in the Atmosphere-

http://www.co2web.info/hawaii.pdf

 and thus T V Segalstad arrives at the following conclusion:-

"At least 96% of the current atmospheric CO2 comes from non-fossil-fuel sources."

Does this address the same question as:-

How much has CO2 risen in our atmosphere due to anthropogenic causes?

T V Segalstad would like you to think so and numerous other web sites/blogs by the same author and others use the confusion to make further flawed conclusions. For example:-

“Hence for the atmospheric CO2 budget marine degassing and juvenile degassing from e.g. volcanic sources must be much more important, and burning of fossil-fuel and biogenic materials much less important, than hitherto assumed”.

This later cautiously worded conclusion follows on from a misinterpretation of the first conclusion.  The first conclusion (At least 96% of the current atmospheric CO2 comes from non-fossil-fuel sources.) in the above article may or may not be accurate. That is not the issue that I take up here, however it may appear to lead to the (false) conclusion that our atmosphere has only risen by 4% due to anthropogenic causes.

The flawed argument.

First an analogy.

A bank note analogy:-

Imagine you deposited £100 notes in your bank and went back a week later to withdraw your money and the cashier apologized and said only £4 of your original notes were left in your branch of the bank so you can only withdraw £4.

Surely this is not the mistake the author makes with the distractions of using the science of carbon isotopes ratios? Yes the analogy is incredibly quite similar and yet with this mistake, and a few others on the way, other false conclusions regarding the half life of CO2 in the atmosphere and the % contribution of CO2 to the greenhouse effect are then obtained. The confusion and false conclusions are carried forward to another article by the same author, and can be read in the following link.

http://www.co2web.info/

Pre industrial global carbon reservoirs.

These are given in figure 2 below. The main point here is that the reservoirs in the biosphere and the oceans are much greater than the atmospheric reservoir.

Figure 2:- Global carbon reservoirs.

The short term carbon cycle.

The short term carbon cycle deals with the movement of carbon between the atmosphere, the ocean and the biosphere. (The long term carbon cycle concerns the movement of carbon from volcanic activity as a source and the sinking of carbon by both weathering of rocks and the smaller but significant burial of organic carbon).

Figure 3:-  Pre industrial carbon.

Exchange of carbon between the atmosphere and the biosphere and oceans is continual and daily which is many times greater than the additional rate of CO2 from fossil fuels over a single year.  This exchange is partly indicated by the net annual cyclic variations that you can observe in figure1 above. However in relatively equilibrium conditions (without the burning of fossil fuels) the net flow is on average zero. Although this is never exactly the case, the approximation to this in pre-industrial times would have been much closer to this as it is in post-industrial times.

Figure 4:- carbon 2014.

When comparing the reservoirs of carbon from pre-industrial to present day levels, figures 3 and 4, it is clear that the atmosphere has gained considerable carbon (in the form of CO2). During this time there has been considerable exchange of carbon into and out of the atmosphere, to and from the biosphere and the oceans, as is always the case. However there will also be a net movement of carbon into the biosphere and the oceans during this time due to the higher CO2 pressure in the atmosphere.

Which molecules stay in the atmosphere?

There is a slight difference in the ratio of carbon isotopes from fossil fuels compared with that from the other sources. However since the ocean and biosphere reservoirs are much bigger than the atmosphere reservoir, this difference in ratio will be much diluted with the continual interchange of carbon between these reservoirs. (This is useful for genuine scientific research in gaining further knowledge about the short term carbon cycle. An explanation of using C13:C12 isotope ratios can be read here ).

The claim “At least 96% of the current atmospheric CO2 comes from non-fossil-fuel sources” merely focuses on which molecules (identified from the ratio of carbon isotopes) are presently in the atmosphere and not how these ratios changed over time.

The C13/C12 ratio has been falling at a slower rate than would be the case if there was no exchange between the atmosphere and in particular the ocean. This should come as no surprise when the exchange is considered but it is this that Segastald has ignored.

For the purpose of deciding “How much has CO2 risen in our atmosphere due to anthropogenic causes”, it should be clear that focusing on which molecules are presently in the atmosphere does in fact not address that question (This is similar to the analogy with the bank notes described above). However, the false claim makes out that it does, with the pseudo science of playing with the data of carbon isotopes. Then with the use of that false connection, further false conclusions are made about the lifetime of CO2 in the atmosphere.

Where has the extra CO2 come from?

T V Segalstad suggests that the increase in CO2 as shown in figure 1 above has come more from “marine degassing and juvenile degassing from e.g. volcanic sources” and not from burning of fossil fuels.

Marine degassing.

If the extra CO2 has come from increasing marine degassing then the oceans must have been warming at a faster rate than claimed in many reports from climate scientists. I don’t think the author would particularly likely you to reach this conclusion, but otherwise how would the oceans start to have a net movement of CO2 into the atmosphere and what could have caused this warming? It further leaves the question where has all the anthropogenic emissions gone? This degassing, however, is not consistent with the levels of ocean pH that has been falling but rather it would require the reverse. It seems that this degassing of CO2 from the oceans is not a reasonable explanation that fits with the evidence.

Volcanic sources.

I think it is beyond all statistical belief to think that volcanic activity has been increasing at the rate equivalent to the rates and timing of anthropogenic production since the industrial revolution. Furthermore the increase in lighter carbon in the atmosphere would require this new coincidental volcanic activity to be coming from the mantle. (The mantle is believed to have a slightly larger percentage of lighter carbon).  However this grasping at straws is not uncommon.

DOES LUNAR SURFACE COOLING RATE REFUTE THEORY OF GREENHOUSE EFFECT?

The temperature at night time on the earth does not fall as rapidly as it would otherwise do if there was no greenhouse effect.The surface of the moon cools rapidly at night fall.

Tuesday 12 07 2014 Alberto Miatello describes in simple terms why he believes that lunar surface cooling rate refutes the theory of the greenhouse effect (GHE). This was published in Principia Scientific where you can read this article. It seems that a few simple yet astonishingly serious errors have been made here playing with data.

http://www.principia-scientific.org/why-lunar-heating-cooling-disproves-the-greenhouse-effect-theory-on-earth.html?utm_campaign=Newsletter_July_14_2014&utm_medium=email&utm_source=newsletter

Here are two of his main arguments:-

Point 1:-

 “The highest temperature ever recorded (in the Death Valley, California, USA) was just 56°- 57°C, a meager highpoint when compared to the Moon’s equator where the temperature normally reaches 117°C (390K) . That is more than double the value, although – as we know – the quantity of solar irradiance is the same: 1367 W/m² in both places.”

Point2:-

“we have observed that on the Moon it takes 14.75 terrestrial days = 354 hours (!), at the lunar equator, to “cool off” from the highest temperature (117°C = 390K) to reach the lowest i.e.

 -173°C = 100K”

Somehow the writer implies that this information somehow refutes the greenhouse theory as stated in the title. However in support of his claim he focuses on criticizing a comment that apparently appeared in a “skeptical science blog” which he quotes as saying

“when the sun ‘goes down’ on the moon, the temperature drops almost immediately, and plunges in several hours down to minus 110 degrees C (-166F).”

He doesn’t succeed in disproving this either.

Let us look at both of the points above.

It takes 14.75 terrestrial days to cool from maximum temperature?

Really? The moon has the same face towards the Earth as it rotates. This means that a night or day on the moon is 14.75 terrestrial days.

http://www.universetoday.com/20524/how-long-is-a-day-on-the-moon/

How long would it take for a substance to cool from its maximum value to its minimum value? Exactly the time it takes to cool from its maximum value to its minimum value and assuming the moon’s surface heats and cools approximately symmetrically this will be half a moon day.
Has the second point actually said anything? Not really. This second point says nothing about the initial rate of cooling after the sun “goes down” which is more than likely similar to that quoted by the skeptical science blog. This would be greater than the extremely slow rate towards the end of the cooling period.
The writer then works out a meaningless average rate of cooling which to no surprise ends up less than the average rate of cooling on Earth..simply because the Earth has shorter days.

It should now come as no surprise that it takes 14.75 terrestrial days for the surface of the moon to warm from its minimum to its maximum temperature.

How fast does the surface of the moon cool?

In fact most of the cooling takes place not in 14.75 days but in the time the moon is eclipsed by the Earth. In that time the surface of the moon cools by 190C!

It looks like the skeptical science blog was quite accurate but Miatello has gotten this badly wrong as he works out a meaningless average rate.

Enhanced Lunar Thermal Radiation During a Lunar Eclipse

 The temperature doubles!:-

The doubling is that on the centigrade scale not the Kelvin scale. If the temperature difference was 0.1C to 1 C, would that represent a 10 fold difference? The temperature in Death Valley is 330K.

330K to 390K is not double. Notice Miatello omits the 330K but not the 390K !

A planet with an ocean and an atmosphere.

The Earth of course transports heat, reducing the magnitudes of both maximums and minimums, and this is perfectly consistent with a GHE theory that can increase the average air temperature.

Sea Level and Ice Melt

Both present sea level rises and ice melt are well documented but it has been claimed (by some) that this information has been misleading or scaremongering. Is this claim justified?

Predicted sea level rise.

Here is “my prediction” (figure 1) of sea level rise by the year 2100.Useless isn’t it?

Figure 1 A prediction of sea level rise.

I am using the estimate for the average depth of the oceans to be 14 000 feet (http://oceanservice.noaa.gov/facts/oceandepth.html) I think you will agree that my graph above (figure 1) is quite useless, unless my intent was to say don’t worry sea level is hardly going to rise. From the graph you may be hard pressed to say the increase was somewhere between 0 and 2%. That is somewhere between 0 and 280 feet; somewhere between no ice melting and all the ice on Earth melting. This is not the way to present data and so here (figure2) is the data presented in a way that is meaningful:-

Figure 2 Present rates of sea level rise. (July 2014  Nasa)

For updates:-  http://climate.nasa.gov/vital-signs/sea-level/

Using this information you can easily work out that if this present trend continues, without further acceleration, the sea level will rise by about 27 cm by year 2100. (This is at the lower end of the recent IPCC report 2013).

Presentation of data.

I think you will agree that the NASA presentation of data is far more useful than the kind of presentation depicted in figure 1. Most people are not really interested in the average depth of the ocean or have any natural “feel” for the significance of this. However sea level rise above what we experience is easily understood. Surely if one were to argue that the data should be presented as in figure 1, looking at the whole depth of the ocean, then it would get little support. However this is the type of claim being made here by  E. Calvin Beisner and J.C. Keister posting on WUWT.

Lying with Statistics: The National Climate Assessment Falsely Hypes Ice Loss in Greenland and Antarctica

Ice melt.

Unlike sea level, people in general don’t have an intuitive feel for either the total amount of land ice (on Greenland, Antarctica and mountain glaciers), or the amount of ice that is melting.  Thus claims that information on ice melt being hyped up may be believed by the casual reader, whereas if we use the same reasoning to sea level rise the claim would be easily spotted as unjustified. The Land ice melt information from NASA is given below. (figure 3)

Figure 3 Land Ice

Choice of presentation.

The data should be presented in such a way that it useful. Claiming that this sort of information as given in figure 3 is “lying with statistics” where information (which shows ice anomaly) is easily obtained, should really be compared to the proposed presentation as given in the form of figure 1 (which shows absolute values). This later form of presentation, exemplified by figure 1, can lead the reader to believing there is nothing to be concerned about whether there is or isn’t a case for concern.

I think if the National Climate Assessment or NASA presented their data in the way suggested by  E. Calvin Beisner and J.C. Keister it would be quite rightly criticized. It seems that the claim of “playing with Statistics” could be more appropriately aimed at the writers of this claim. These writers would seem to prefer the data to be presented in a way that no useful information could be obtained; no way of seeing if the data was consistent with other data; and no indication of whether there was need for concern or not.

Intent to Deceive

Manipulating data can be done in such a way, that although technically correct, it can then be displayed to appear to say something that is quite false. Here I will look at a blatant attempt to deceive by such a practice.

C3 headlines set out to show that there was no significant global warming but merely shows there is an insignificant decline in the rate of warming.

First of all the information before it has been manipulated.
This concerns the global surface air temperature and CO2 levels over the last 35 years.

Figure 1 Met Office data.

The latter part of this graph (red box) shows the global temperatures changes over the last 35 years of about a 0.5 C rise. Can this be manipulated to imply a temperature drop of about 0.04C per century over this same period?  Here is one such attempt by a site that in fact does this…

http://www.c3headlines.com/2014/07/state-of-the-art-satellite-technology-provides-proof-co2s-almost-non-existent-global-warming-influence.html#commentsd

…. and then incredibly goes on to say:-

“The political agenda of "global warming" is so important to government-sponsored scientists that massive fabrication of temperature warming is required to convince policymakers and the media”.

Figure 2 copied below from this site above uses similar data to figure 1, but presents it in such a way to make this implication described above.

Figure 2. Satellite data manipulated.

Both the vertical axes have been presented in such a way as to hide any useful information and encourage the reader to make false inferences. Look no changes in the temperature and massive changes in CO2 (“statistically significant, ZERO”) and trend/century = -0.04C.

6 Month temperature anomaly change.

This of course is a measure of the rate of change of temperature. We can see from figure 1 that the rate of change of temperature is greater in the first half of this period of time but there is a lot of natural variation superimposed on this. The rate of temperature therefore has marginally declined but statistically by an insignificant amount.

If the temperature had risen linearly without variations how would a 6 month anomaly graph appear?

Figure 3 above shows how a 6 month anomaly graph would appear if there was no natural variability and the fraudulent implication would be easily recognized. However the natural variation possibly and hopefully distracts the reader from observing this fraud.  Why 6 months. A 6 month anomaly maintains the natural variability while keeping the familiar scale and still keeps a small enough offset value to give maximum deception.

The cumulative Atmospheric CO2 level.

It is common among climate “skeptics” to play down the amount of CO2 that has accumulated over this time. However in figure 2 the technique is to play up the CO2 level; to make it appear as large as possible to compare with the deceptive downplay of temperature changes.

The technique is to get CO2 increases to go from the bottom left of your screen to the top right of your screen. This is easily achieved now by assuming a starting value of zero and adjusting the independent CO2 scale accordingly.

Comparing a rate of change to absolute values.

There is nothing wrong with using this technique to show that two variables are related when this makes it clearer. For example one might speculate that the rate of loss of ice during a de-glaciation part of a cycle is related to the insolation received in the northern hemisphere during the well known Milankovitch cycles. However to use a rate of change or any other manipulation of data to obscure a relation or to attempt to show that variables are not connected is not in any way useful unless it is your intent to deceive.

This article set out to show that there was no significant warming but merely showed an insignificant decline in the rate of warming.

Carbon dioxide, temperature and natural variation.

Carbon dioxide can be both a cause of increasing temperature and an effect of increasing temperature.

The temperature over the last century has been increasing due to an increase in CO2 mainly from the consumption of fossil fuels. We can also see from paleo climate records that increasing temperatures can lead to carbon dioxide being released from the oceans and acting as a feedback. If the oceans warm then CO2 is released and this CO2 causes further warming.

Climate contrarians would like to suggest that the CO2 in our atmosphere has built up from the oceans warming and equally has no effect on warming. If true this would beg the following questions:- Where has the carbon dioxide from fossil fuel burning gone and what has caused the warming?  The contrarians don’t have coherent arguments for these questions though and instead try to find evidence to spread doubt on global warming being caused by increasing greenhouse gases.

Here I will describe some mathematical techniques that involve playing with data to try to convince you that CO2 lags temperature even in today’s changing atmosphere and temperatures due to the burning of fossil fuels. This in the hope that: - readers will falsely infer that CO2 in our atmosphere has built up from the oceans warming and equally has no effect on warming.

First here are graphs showing changes in temperature and CO2:-

                                               Figure 1 changes in CO2 over last 50 years.

                                      Figure 2. Changes in temperature over the last 160 years

In figure 1 the trend in increasing CO2 can be readily seen and also the seasonal variation that affects the CO2 in our atmosphere. This is numerically consistent with the amount of CO2 emitted from humans with about half being taken up by the biosphere and the oceans due to the increased partial pressure of CO2. This is in spite of oceans temperatures rising that would diminish this uptake.  Interestingly the trend seems to have small random variations due to natural variations of a secondary nature.

In figure 2 the trend in increasing temperature is also clearly seen along with variations due to natural variations. These natural variations include small changes in solar radiation, changes in ocean circulation such as the El Nino S.O. , and changes in aerosols from volcanic eruptions blocking sunlight. (There is also a period after 1940 of cooling.  This coincides with the anthropogenic release of aerosols, due to the increase of burning “dirty” coal.)

The CO2 trend is the main cause of the trend in the temperature, and the seasonal changes in plant growth in the Northern hemisphere is the cause the yearly cyclic variation seen in figure 1.

The cyclic 11 year cycle of solar activity with a slight decreasing trend cannot account for the warming trend being of the wrong magnitude and lately of the wrong sign but it CAN account for some of these variations.

If mathematically the trend is removed and the seasonal cycle is removed then the variations can be seen clearer. However if this is done we obscure any connections about the trend in CO2 and trend in temperature. There are good mathematical ways of removing the trend and the seasonal cycles but Ole Humlum crudely achieves this by “showing monthly values (in the graphs) of DIFF12. This is the difference between the average of the last 12 month and the average for the previous 12 months for each data series. This is shown here in figure 3

                                                 Figure 3 DIFF12 CO2 and temperature.

Ole Humlum produced this graph to falsely conclude that CO2 lags temperature in today’s atmosphere and Anthony Watts at WUWT falsely conclude that this is evidence that suggests that man made CO2 is not the driver ofglobal warming.

What does a “Diff12” do to data?

In short it smoothes out variation to some extent and then differentiates as in normal calculus.

1. As in normal calculus differentiation this will turn a linear trend to a horizontal line offset from the origin.

2. A sinusoidal cycle over twelve months will disappear.

3. Other variations will be differentiated as in normal calculus.

What can we observe from these graphs?

1. The blue graph will have the seasonal cycles removed and the average value which is just slightly positive will be the trend of the rising temperature over this time period expressed in degrees C per year. (This is the trend that is caused by the trend in CO2).

2. The blue graph also has variations (other than the seasonal cycle) which represent natural variation changes per year. (This is likely the rate of change of variations due to mainly to the ENSO cycles).

3. The green graph shows the rate of change of CO2 again with seasonal cycles removed. It shows if the last 12 month period had more or less CO2 than the previous 12 months.

4. The green graph shows (assuming no errors in data handling by Humlum) that these variations in CO2 lag the variations in the temperature.

(We can further see more clearly:- that the rate of CO2 build up is increasing  slightly and the rate of temperature build up has been roughly constant. The rate that temperature is increasing is fairly constant is clearly seen here because any peaks in temperature that are above the trend line in figure 1 are less likely to be deceptively used as a starting point.)

Speculation:-

There is absolutely nothing wrong with adjusting the data in this way as long as conclusions do not ignore the alterations that have been done but rather take into account what has been done. If this has been done accurately, one may speculate for example that some natural variation (ENSO)is causing the sea to warm at a different rate and the ENSO is also affecting  the short term variations of CO2.

(One may also speculate that the natural variation is causing the sea to warm at a different rate and this change in warming then affects the rate at which CO2 is absorbed into the oceans. This would imply some direct evidence of a positive CO2 feedback.... I think a speculation that Humlum or WUWT would resist).

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However this later speculation is unlikely to be the case.
a). TheCarbon Cycle Response to ENSO has been discussed by Jones et al 2001 and this supports the former speculation.

“"Climatic changes over land during El Nino events lead to decreased gross primary productivity and increased plant and soil respiration, and hence the terrestrial biosphere becomes a source of CO2 to the atmosphere. Conversely, during El Nino events, the ocean becomes a sink of CO2 because of reduction of equatorial Pacific outgassing as a result of decreased upwelling of carbon-rich deep water. During La Nina events the opposite occurs; the land becomes a sink and the ocean a source of CO2."

b). In addition to the land becoming a carbon sink during La Nina as described by Jones, Behrenfield et al suggest that oceanic phytoplankton would increase during La Nina also, due to the upwelling off nutrients. This would work in the same direction as suggested by Jones i.e. CO2 decreasing during La Nina years.

What can we conclude from Humlum's graph?

We can conclude the CO2 variations are not directly the driver of the natural variability in sea temperature changes. (If you want to see clearly the correlation between CO2 and the rise in temperature you must replace the trend that has been obscured.)

We cannot conclude however that the trend in CO2 is caused by the temperature as implied by Humlum.

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 The short term variations in SST are not the cause of the short term variations in CO2 but rather both of these variations have some other common causes including ENSO. Further these correlations can be explained and of course having nothing to do with the correlation in the trends.