Carbon dioxide rise, swing and spread (seasonal fluctuations) are addressed in this study. Actual CO 2 concentrations were used rather than dry values. The dry values are artificially higher because water vapor must be removed in order for the NDIR instrument to work and is not factored back into the reported numbers. Articles addressing these observations express opinions that are divergent and often conflicting. This investigation resolves many of those inconsistencies. The data were obtained from many measuring stations at various latitudes since 1972 and then graphical compared to changes in sea temperatures, fossil fuel emissions, humidity, and seasonal ice and snow changes. In analyzing the data, various parameters were addressed including: variability, R squared curve values, correlations between curves, residence times, absorption percentages, and Troposphere effects. Mass balance calculations were also made to corroborate viability. The CO2 “rise” over a 33 - year period from a slight ocean temperature increase (0.7°F) contributed 2.3 percent of the total rise while fossil fuel emissions contributed 1.5 percent. The overwhelming majority (60 ppmv, 96%+) was caused by other factors including ocean and land biology as well potential errors in fundamental hypotheses. With respect to “spread” (seasonal CO2 fluctuations) at the Polar Circles, graphical analysis with high correlations supported by mass balance calculations confirm that ice and snow are the primary cause and explain why the concentrations are the highest at these cold locations. The global variations in “swing” remain uncertain.
Charles Keeling meticulously studied carbon dioxide variations from the Mauna Loa Observatory in Hawaii and penned the famous “Keeling Curve”. This curve formed the foundation for essentially all atmospheric CO2 studies, both the yearly rise and the seasonal oscillations. Keeling unequivocally discovered that the average CO2 concentration1 has been rising over the last 100 years and that it fluctuates with the season with the Northern Hemisphere (NH) exhibiting the largest change.
There are three basic types of CO2 observations. The “rise” is the most publicized and well known. It is the amount of CO2 that increases every year. The monthly fluctuations or how the concentration changes with the seasons is the “spread”. The third type is the “swing”. It is similar to spread but measures the high and low differences between latitudes. Essentially, rise uses the same month and same latitude but different years; spread uses the same latitude and same year but different months; and swing uses the same month and same year but different latitudes.
The rise has been the subject of many scientific studies and forms the foundation for the global warming theory. Many believe that the “rise” is caused by burning fossil fuels [
Other scientific papers postulate that the yearly spread or seasonal oscillations are caused by a combination of fossil fuel emissions and bio respiration as moderated by a stronger than expected NH sink [
Scientific studies of the “swing” are typically discussed as subsets of rise or spread investigations.
The IPCC (Intergovernmental Panel on Climate Change, a division of the UN) lists the largest atmospheric CO2 exchanges, i.e. the total of emissions (sources) and absorptions (sinks). Included in this list are oceans at 182 GtC/yr, land plant biology at 102 GtC/yr and land soils at 100 GtC/yr. Fossil Fuel emissions sit at 5 GtC/yr. [
There is a close inverse relationship between seasonal changes in sea temperatures and seasonal changes in the carbon dioxide concentrations. That is, when sea temperatures fall the atmospheric CO2 concentration increases, and when temperatures increase CO2 goes down. The same inverse relationship occurs with air temperature, i.e. a rising temperature and a falling CO2. Some scientists used the inverse land/air temperature relationship as a proxy for a biological connection, i.e. as the temperature goes up, land plants grow and consume CO2 by photosynthesis (sink).
None of these studies have adequately answered the question as to why the North and South Polar Regions each have the highest CO2 concentration, or how a lack of land bio-masses within 1000 kilometers of either pole could cause such a high concentration. This study addresses all three types of observations: rise, swing and spread, as well as the potential causes for each. It also provides an explanation for why these cold regions record the highest CO2 concentrations.
According to the NOAA’s (National Oceanic and Atmospheric Administration, a division of the US Department of Commerce) description of the laboratory test [
The CO2 test procedure reports an artificial or dry concentration―not the actual concentration. Since the water vaper in the air can constitute about 3% of the air in equatorial waters, removing it increases the dry CO2 concentration by 12 to 15 ppm. This is because a cubic meter of any gas contains the same number of molecules (Avogadro’s number) at the same temperature and pressure regardless of the kind of molecules present. If 3 percent of water molecules are added or removed, it will change the percentage of the other gases by the same ratio, i.e. 3 percent. The equatorial regions contain a significant amount of water vapor while the Polar Regions contain very little. In these colder regions the removal of the water has very little effect on the actual CO2 concentration.
The explanation for reporting the dry CO2 concentration and not the actual CO2 concentration is that humidity varies between day and night and between high and low altitudes. This would result in a variable concentration and make comparisons difficult. In addition, if the CO2 data are reported as anomalies (comparative change) then the anomalies in the dry CO2 concentration would be very close to the anomalies in the actual CO2 concentrations. That is, the change (anomaly) in the dry CO2 concentration from the previous day, month or year would be very similar to the change (anomaly) in the actual CO2 concentration from the same previous day, month or year. Both of these explanations are technically correct. However, just because something is difficult to accurately track does not mean that there is a valid reason to disregard it.
Plots of dry CO2 anomalies compared with actual CO2 anomalies show that the two are indeed exceptionally close. Therefore if anomalies are the only thing being considered, then there is a valid reason for using dry CO2 concentrations as a proxy for actual CO2 concentrations.
Scientists have become so accustomed to the “Keeling Curve”, that many have missed the distinction between dry and actual. This can result in some errors and confusion.
A particular problem occurs with entropy. At the Poles, the dry CO2 concentration is essentially equal to the actual concentrations. But with each drop in latitude, there is a corresponding increase in water vapor, and the difference between dry and actual becomes higher and higher. This difference ranges from 0 - 2 ppm in the Polar Regions and increases to 13 - 15 ppm at the equatorial regions. With respect to entropy, this is a significant issue. For example, in August 2014 the North Pole (Alert 82˚N) had a dry CO2 concentration of approximately 389 ppmv. At the equator (Christmas Island 1.87˚N) for the same time the dry concentration was 397 ppm. This suggests an August mass flow driving force (∆8 ppm) toward the North Pole. It further infers that CO2 may be accumulating in the lower latitudes; and some have suggested that it is the result of fossil fuel burning. But the actual CO2 concentration at Christmas Island was 382 and not 397. This shows that the mass flow driving force is in the opposite direction―from the North Pole to the equator and does not support an equatorial accumulation.
Actual CO2 concentrations can be calculated at the time of sampling by measuring the temperature and relative humidity. Humidity measurements can also be ascertained during laboratory testing by recording the amount of water in the water trap per unit of sample volume.
Unfortunately, neither of these humidity measurements were reported. The humidity can be estimated by determining the average humidity at a location near the CO2 sampling station.
explain the spike in humidity at 30 degrees. There is an inverse spike of CO2 near 30 degrees, i.e. a dip in CO2 that mirrors the increase in specific humidity. Like sea and air temperatures, the inverse relationship between atmospheric CO2 and ocean humidity is consistent and its cause uncertain.
In this investigation the average specific humidity at each measuring station was used. It is recognized that using averages is less accurate than using actual numbers. The average humidity does not reflect that the water vapor content has been rising each year [
One study [
In the Polar Regions the dry CO2 and the actual CO2 concentrations are nearly the same. This is illustrated by
with
In summary, the actual CO2 concentrations are similar to the dry concentrations but shifted downward. The amount of downward shift increases with decreasing latitudes in both hemispheres. The use of anomalies masks the downward shift.
All of the figures and tables shown/discussed hereinafter are based on actual CO2 concentrations and not dry concentrations unless otherwise indicated.
The 2011 monthly variations in the Northern Hemisphere (NH) were more erratic than those in the Southern Hemisphere (SH). At −90˚S the spread was about 2.5 ppmv with fluctuations grouped into three 4-month segments. That is, the high concentrations lasted about 4 months, the lows for 4 months, and the transitions at 4 months. The NH had a spread at Barrows almost 8 times greater at 20 ppmv. The highs lasted 6 months, the low lasted 1 month, and the transitions spanned 5 months.
The NH comparison is different from the SH in that Barrows, Alaska is located at 71˚N and not 90˚N, and requires a latitude adjustment. There were some differences with the 2011 observations between latitudes, particularly around 30 degrees. The spread in the Southern Hemisphere (SH) ranged from about 0.8 ppmv at the equator to 4.5 ppmv at −30˚S whereas the spread in the Northern Hemisphere (NH) ranged from 0.8 at the equator to 20.8 ppmv at Barrows, Alaska. The observed spreads were many times larger in the north.
The 2011 swings were also different. The minimum swing occurred in February- March in the SH at about 8.4 ppmv. In the north, the minimum swing was 8 times less occurring in August at 1 ppmv. The maximum swing occurred in October in the SH at about 11 ppmv while it occurred in April in the NH at 19.8 ppmv. In the SH the driving force (delta concentration) varied from ~11 ppmv (Oct) to ~8.4 ppmv (March). The NH, on the other hand, had a driving force of 19.8 ppmv (April) to 1 ppm (Aug). This shows a maximum difference in push-pull force of 19 ppmv in the north and 2.7 ppmv in the south.
The vectors were additive (accelerates flow) anytime there were decreasing CO2 concentrations, and subtractive, (inhibits flow) during times of increasing concentration.
This is illustrated in the above graph when the concentration was dropping, i.e. May and August it took 3 months to complete the drop. When the concentration was increasing, i.e. September to December it took 3.5 months to accomplish the same spread. The lower CO2 concentrations from lower latitudes likely rob (inhibit) a portion of the CO2 from building at the higher latitudes between Sept to Dec thereby slowing the accretion and adding (assists) in the other direction. There are other one-year cyclic systems that may have a faster rise/drop direction and could be additional factors in explaining the observations. It is possible that ice melts or freezes more quickly in one direction than the other. The heat of fusion (freezing/melting) traveling into a point may be different from heat radiating outward. It is possible that sea temperatures rise or fall faster in one direction. Perhaps the ozone layer is preferentially weaker or stronger during the year and this process affects temperatures, ice formation or melting, soil desiccation, and/or CO2 absorption/ejection. Or it may be a combination of all of these factors and others.
Whatever the actual causes, the mathematical vector analysis assists engineers in exploring the potential causes and effects.
The CO2 concentration profiles displayed in
The January rise plotted in
The January swing exhibited ~16 ppmv in 1986 that increased to ~20 ppmv in 2014. The swing increased about 4 ppmv in 28 years or 0.14 ppmv/yr. The swings varied greatly (1 - 20 ppmv) between months in the NH as shown in
The spread is not shown in
The January rise plotted in
The following
The swings were not presented in the
There may be some discrepancies between
Station | Lat. | Ave CO2 (ppmv) | Max Spread (ppmv) | Max Spread (Percent) | Ave Rise/yr (ppmv) | Ave Rise/yr (Percent) |
---|---|---|---|---|---|---|
South Pole | −90˚S | 369 | 3.02 | 0.81% | 1.66 | 0.45% |
Palmer Station | −64˚S | 365 | 3.68 | 1.00% | 1.69 | 0.46% |
Ushuaia, Argentina | −54.8˚S | 371 | 4.12 | 1.11% | 1.79 | 0.48% |
Cape Grim | −41˚S | 363 | 3.51 | 0.96% | 1.68 | 0.46% |
Pacific Ocean | −30˚S | 358 | 4.08 | 1.14% | 1.57 | 0.44% |
Easter Island | −27˚S | 366 | 4.49 | 1.23% | 1.86 | 0.51% |
Pacific Ocean | −25˚S | 357 | 3.95 | 1.11% | 1.66 | 0.46% |
Pacific Ocean | −20˚S | 356 | 2.75 | 0.77% | 1.64 | 0.46% |
Somoa | −14.3˚S | 358 | 3.01 | 0.84% | 1.55 | 0.43% |
Pacific Ocean | −10˚S | 357 | 1.32 | 0.37% | 1.59 | 0.44% |
Pacific Ocean | 0˚ | 359 | 1.37 | 0.38% | 1.5 | 0.41% |
Christmas Island | 1.87˚N | 358 | 2.28 | 0.63% | 1.64 | 0.46% |
Pacific Ocean | 10˚N | 360 | 6 | 1.67% | 1.73 | 0.48% |
Barbados | 13.1˚N | 365 | 7.29 | 1.99% | 1.69 | 0.47% |
Pacific Ocean | 15˚N | 360 | 6.19 | 1.71% | 1.66 | 0.46% |
Mauna Loa | 19.5˚N | 365 | 6.22 | 1.7% | 1.69 | 0.46% |
Pacific Ocean | 25˚N | 366 | 15.1 | 4.1% | 1.68 | 0.45% |
Midway | 28.2˚N | 368 | 14.1 | 3.8% | 1.75 | 0.47% |
Azores | 38.7˚N | 368 | 16 | 4.4% | 1.70 | 0.46% |
Cold Bay, Alaska | 55.2˚N | 373 | 20.2 | 5.4% | 1.7 | 0.46% |
Barrows, Alaska | 71.3˚N | 376 | 20.8 | 5.5% | 1.6 | 0.43% |
Alert, Canada | 82.4˚N | 376 | 20.193 | 5.4% | 1.77 | 0.47% |
uses a larger number of sampling stations than the figures, but many of the sampling stations did not have data going back to 1976.
Figures 10-16 graph the rise and spread changes in terms of percent. The February data were used to compute the rise for the SH and the April data was used in the NH. The yearly rise for all latitudes showed a similar slope. With respect to spread, the maximum and minimum months of October & February (winter-summer) were used for the Southern Hemisphere and April & August (winter-summer) were used for the Northern Hemisphere.
These dates were selected because many of the sites did not have sufficient data for earlier years. Percent’s were used to show relative changes.
These figures illustrate that the relative changes in the Northern Hemisphere were very similar to the relative changes in the Southern Hemisphere. For example, the 28 year rise in CO2 in the Southern Hemisphere changed from 343 ppmv to 393 (∆50) while the NH changed from 349 ppmv to 401 (∆52). All of these figures show that the rise was exceptionally smooth exhibiting an R squared statistical variation at 99+ percent while the spread was highly variable with an R squared varying from near zero to a high of 30%. Percentages were used to show relative changes and the side by side comparisons at equivalent latitudes in opposite hemispheres. This provided a means for measuring relative effects from one hemisphere to the other.
The results are shown in
R squared is a number that indicates the proportion of variance in dependent variables along the same curve. A high R squared indicates that there is a strong relationship. For example an R square of 1 is a perfect match, meaning that all data points fall on the curve line. There are some caveats that must be considered. R squared does not mean
SH Location | Percent Change | NH Location | Percent Change |
---|---|---|---|
N Pole (−90˚S) | 15% | Alert, Canada (82˚N) | 15% |
Cape Grim (−41˚S) | 15% | Azores, Port (38.7˚N) | 15.5% |
Samoa (−14˚S) | 15.8% | Mauna Loa (19.5˚N) | 15.5% |
Average SH | 15.3% | Average NH | 15.3% |
that the independent variables are the cause of the changes in the dependent variables. It may also have a potential bias problem if there are applicable variables omitted. A high or low R squared does not prove/disprove causation in fact. On the other hand, the R squared value is a factor that can be considered in proving causation. It is generally easier to use R squared as a means for disproving a relationship.
Correlation is similar to R squared but deals with different curves. Correlation measures the variance between two curves. It is the average of the summation of each percent deviation between curves at each data point. R squared is how data points fall on a curve and correlation is how two curves match up with each other. A correlation of 100% means that the two curves fall on top of each other. Correlation does not prove causation in fact, but is relevant in proving causation. A poor correlation is strong evidence disproving causation
Variability and lack of variability are meaningful even in the absence of other factors. High variability suggests that it is probably responsive to large changes. For example, adding 50% of the total to a mixture will show a significant change, whereas adding 0.1 percent may not. Therefore the magnitude of change (Magnitude Factor) will have an effect on the variability. This can be illustrated by the spread (seasonal change) of 4 ppm in the SH and 20 ppm in the NH. This represents about 1 percent (4/400 ppm) change in the South and 5 (20/400) percent change in the North in one year. The yearly rise, on the other hand, is less than 0.5% in both hemispheres. The rise is 2 to 10 times less than spread and reasonably suggests that the larger magnitude would trigger a greater response―and the observational data showed that it did.
Another factor is time (Time Factor). Included in this time factor is the speed in which the product is released, the time it takes a product to mix, and the product’s life expectancy. Each affects variability. These time factors may affect the short term and long term variability differently. For example, a product that quickly dies out may have large effects on short term variability but little effect on the long term variability. These time factors may also work in different directions (subtractive) and/or in the same directions (additive).
Release speed, mixing time and product life are independent time variables and are difficult to continuously measure and estimate. Residence time is a combined measurement of product life and mixing time, particularly in the absorption and de-absorption situations. Release time is more independent and more unrelated to residence time. Residence time is an estimate/computation of how long the product stays (in this case) in the atmosphere. The higher the residence time the longer the product will accumulate and the less variable it will become. Carbon dioxide moves into several atmospheric levels (troposphere, stratosphere, and mesosphere) so the volume that must be affected is extremely large. Water vapor on the other hand is mostly limited to the troposphere. This means that the travel distance for CO2 is larger than water vapor. It may mean that time smooths changes inCO2 far more than water vapor. Carbon dioxide has a long residence time (most studies put it in the 50 - 100 years) while water vapor has short residence times, i.e. weeks to a few months.
The lack of aberrations in the rise data suggests that it has been smoothed by immense volumes (Magnitude Factor) and/or spread over vast distances with a long lifespan (Time Factor). Small fluctuations from sudden environmental phenomena do not appear, i.e. volcanoes, winds, hurricanes, monsoons, ocean currents, etc. The “release time” does not appear to be a consideration because the seasonal concentration fluctuations line up with the months and were not shifted significantly. This suggests that the release time is very short―days to a couple of weeks. The changes in volumes (Magnitude Factor) are generally identified in
One study [
The 33 year residence time has been selected for investigation using the Andrews model. With this model, an operative percent for each year is calculated based on the integration or summation of the carbon dioxide concentrations over the last 33 years. In this model the current year has the highest effective percentage (6.4%) and diminishing in accordance with a second order polynomial equation to a zero influence on the 33rd year.
All of the figures and Tables in this article deal with CO2 concentrations. Concentration is a ratio of the volume of CO2 to the volume of the air. Most scientific studies focused on the top half, i.e. volume of CO23 and do not discuss the bottom half, i.e. volume of the air, or they base their analysis on a cubic meter of volume. For a cubic meter of volume, 1ppmv is the same at the equator as it is at the Poles for the same pressure and temperature. However, when considering the total amount of CO2 in each Troposphere zone, the volume of the each zone is a component. The earth’s circumference and therefore the Troposphere volume varies dramatically depending upon the latitude. In order to compare the effect of releasing tonnes of additional CO2 into the atmosphere at a particular location there must be a consideration of the volume of the atmosphere at that location. Because of the earth’s spin, there are also changes in the troposphere height (7 km at the Poles and 20 km at the equator). As an illustration, the Troposphere volume of the Arctic Circle (90˚N - 66.5˚N) is about ~9.7 times less than the volume of the Troposphere at the equatorial region for the same latitude range (0˚N to 23.4˚N― Tropic of Cancer). Many scientific studies, particularly relating to fossil fuel emissions, appear to equate GtC with ppmv of CO2 [
The Troposphere effect is substantial, but only in the short term, i.e. less than 1year. When CO2 is released at a particular location, it has an immediate effect at that location. However, over time it is mixed by winds, etc. and the effect diminishes. The vertical mixing in the Troposphere takes about 1 month (less at the polar areas) and the time it takes to mix around the earth is about 1 year. Mixing times can be extremely hard to mathematically simulate because of the differences in winds, pressures, temperatures, and absorptions. Globally, the mixing time is estimated to be about 1 year with the SH being faster and the NH being slower. As such, the Troposphere effect will be less and less significant with the passage of time. It would have large effects on “spread” or seasonal (monthly) fluctuations, but very small effects on rise over multiple years. It would also have an effect on short term “swing” (within a year), but less if it relates to changes over multiple years. It is recognized that CO2 travels to the stratosphere and mesosphere, however the mixing time in these higher spheres is more than 1 year and were not considered when applying the short term Troposphere effect.
Studies have reported connections between rising ocean temperatures and rising CO2 concentration [
99.88%. The global sea surface temperature, on the other hand, was more variable with an R squared of 75% using the same 2nd power polynomial curve. This figure illustrates that both curves appeared to be related as far as the long term upward slope but inversely related as to curvature at the center. As discussed earlier, the CO2 rise data closely fits a 33 year residence time.
The near surface sea temperature releases CO2 in various amounts at various locations. This CO2 does not enter the atmosphere unimpeded nor is there instantaneous mixing. The CO2 released at the ocean surface in any particular year undergoes many absorption/ejection cycles, biological actions, scrubbing by rains, etc. as it enters the mixing phase in the atmosphere. It should be subjected to the same time smoothing (33 years) as the CO2.
1) Mass Flow Analysis
A mass flow analysis by itself cannot prove causation, but can often be used to disprove it. That is, even if the mass flow calculations show that the temperature increase can cause the observed rise, it does not prove that it did.
There are varying causation hierarchies. If the calculation shows that the product cannot be produced by the occurrence/process, then there is no causation. If the mass flow calculations show that an occurrence/process produces more than the amount needed, then it “can” cause the effect. If the calculations prove that occurrence/process “can” produce a significant portion, but not all, then it may be considered to have a partial causal connection.
2) Mass Flow Calculations
This calculation is directed to whether a 0.7˚ Fahrenheit increase in ocean temperature can cause enough CO2 to be released to increase the atmospheric concentration by ~60 ppmv over a 33 year period (1981-2014). According to IPCC each 1 ppmv of atmospheric CO2 equates to 2.21 GtC [
The fact that there was 64% more than needed indicates that a portion of the CO2 released must have been absorbed. The question as to how much is not easily computed. If the atmosphere is considered as a whole, then all of the up CO2 flux was 197 GtC/yr [
Either, the assumptions were incorrect, more than the top 1000 meters of ocean water were involved, the absorption percentage was less than 98.48%, or there were other sources adding to the atmospheric carbon. The obvious answer is all of the above, but “other sources” is the most probable. Other sources include fossil fuel emissions, CO2 released by fresh water lakes and rivers, changes in land and marine biomasses, soil desiccation, volcanic emissions, chemical processes, etc. There may also be a fundamental error in way the carbon flux was estimated, i.e. it is possible that the massive fluxes were back-calculated from an accurate knowledge of the CO2 accumulation, and not from any precise measurements of actual ocean/biomass breathing. Attempts to estimate this exceedingly complex process would not be verifiable. There may also a potential problem associated with comparing actual CO2 concentrations with a temperature “anomaly”.
Before analyzing the “other sources”, there are some unrelated observations from
The slight temperature rise of 0.7˚F over 33 years is overwhelmed by the seasonal ocean temperature fluctuations. For example the ocean temperature changed 10˚F at Cape Grim (
In summary, the exceptionally close curve match indicates that the ocean temperature rise matches the CO2 rise. The mass flow calculations support the rise, but an absorption factor would need to be applied. After a 98.45% absorption factor is applied, the ocean temperature effect on CO2 rise is very small, i.e. 2.3% of the total.
The topic of CO2 associated with fossil fuel burning has been the subject of most Climate Change publications. CO2 emissions from fossil fuel burning have been increasing since the 1950’s.
from the fossil fuel combustion goes directly into the atmosphere unimpeded and mixes within a year. That is not the case. There are many absorption/ejection cycles, biological actions, scrubbing by rains, etc. as the CO2 enters the mixing phase in the atmosphere. With respect to long term rise, the CO2 emissions curve should be integrated over the same 33 year period as the global CO2 rise. Both curves show an R squared value above 99% indicating that the data supporting each curve is exceptionally consistent.
An engineering mass/volume analysis can be performed based on the IPCC’s statement of 5 GtC/yr. This amounts to 165 GtC over 33 years. The amount needed was 128 GtC. Hence there was 37 GtC more than required, i.e. 29% too much. Applying a 98.48% absorption factor to the emission release provides a net of 1.94 GtC or only 1.5% of the total amount needed.
Proof that Absorption Percent is High. There are seasonal observations that support a large absorption percent. The CO2 concentrations at the stations located above, below and to the west of the United States were plotted on one Y axis and US CO2 emissions tonnage was plotted on the other Y axis. A comparison between the three stations showed no influence by or from the emissions. This is discussed more fully in section E subsection c hereinafter and graphically shown in
The Troposphere effect, as discussed hereinbefore, supports a large absorption percent. According to the IPCC the fossil fuel emissions were 5 GtC/yr [
only in the zone between 30˚N to 60˚N. The fossil fuel emissions (4.5 GtC) are not released in one moth, but over 12 months at approximately 0.375 GtC/month. This is shown by the bottom dotted line. This line assumes that there is no accumulation between months from the release. The vertical dotted line is the middle of the fossil fuel zone. Where it intersects the bottom dotted line is at concentration of 10 ppmv. That is, the average concentration in the fossil fuel zone would go up by 10 ppmv because of the release of 0.375 GtC in one month. The actual observations from stations at those latitudes and compared to others stations showed no measurable effect from the emissions. Hence, a very large absorption must be occurring. In addition, a one month mixing period in that zone is too fast. The second dotted line is a 3-month mixing period where a portion of the CO2 released in the two prior months are added. But it is seriously decayed by a polynomial reduction, i.e. 50% of the previous month and 10% of the month before that are added. This is more realistic and shows that the release of CO2 would increase the concentration in the fossil fuel zone by approximately 30 ppmv. This supports a very high absorption percentage.
In summary: 1) the graphic correlation set forth in
There are many other causes that contribute to the CO2 rise. A few of these include the following:
1) Animal Biology
Biology is the second biggest contributor of CO2 emissions/absorption after the ocean. Biology is also the most difficult to predict. Plants play the major role in consuming CO2 (sinks) but non-plant biomass plays the major role in releasing CO2 (sources) both by respiration and by detritus (decay). Surprisingly, the largest by weight in the non-plant kingdom are the small. Bacterial biomass may constitute as much as 350 - 550 billion tonnes and equals 60% to 100% of all the carbon in all the plants [
Both bacterial and insect density are temperature related. An increase in global temperature over the last 33 years translates into an increase in bacterial and insect density. Hence, this is a viable candidate for the majority of the CO2 rise. Unfortunately biology is massive, complex, and impossible to catalog accurately. Therefore, a mass calculation cannot be performed accurately.
2) Land Soil
The land soil contains 2 - 4 times more carbon than the atmosphere [
3) Volcanic/Tectonic Events
The IPCC believed that CO2 emissions from volcanoes or tectonic events were too small to be considered and did not show that source on their carbon cycle analysis [
4) Chemical Processes
The ejection of acidic gases from volcanoes and production of commercial acids have resulted in these acids accumulating in the air, soil and oceans. The acids enter the water cycle and decrease the ocean pH. These acids react with carbonates (marble, limestone, marine animal shells, etc.) and produce CO2. The size of this chemical process is not known, but with SO2 being one of the dominate gases emitted by volcanoes, it will produce at least as much SO2 as CO2. The global commercial sulfuric acid production is estimated at 230 million tons/year. Although most of these acids are neutralized prior to entering the water cycle, it is likely that a significant amount finds its way into the ocean. In addition some of the sulfur from the neutralized acid is eventually re-oxidized to form SO2 which in turn is converted to sulfuric acid in the atmosphere.
In sum, the “other sources” are viable and could account for the 128 GtC required to increase the concentration by 60 ppmv over the last 33 years.
The causes for changes in the CO2 concentration between latitudes, i.e. swing, have been investigated, but a satisfactory explanation has not been established. The changes in swing in the NH, as shown in
There appeared to be a connection between “rise” and “swing” in the NH. That is, the percent rise and the percent increase in spread with latitude over many years appeared similar. An increase in spread as it applies to latitude translates into an increase in swing. One mechanism considered was that the slow accumulation of CO2 each year (rise) causes a temporary increase in the amount of CO2 absorbed by snow melt. When the snow melt evaporates, it releases slightly more CO2 into the air. However, the swing change (increase) in the NH was ~17.5% between 1986-2014 while the rise in the NH was 15.3% (
The major differences between the NH and the SH is that the north is land-locked whereas the ocean swirls around Antarctica. The land biomass in the north exceeds the land biomass in the south, but the marine biomass is greater in the south. Fossil fuel emissions are 90% higher in the north. The temperature fluctuations are higher in the north and cooler in the south. Significant snowfall change exists outside the Arctic Circle but not outside the Antarctic Circle. This study could not find a strong connection of these factors as it relates to swing.
In sum, the causes for changes in the swing remain elusive.
This section addresses causation of the monthly fluctuations.
Biology is one of the most powerful and misunderstood forces controlling environmental conditions on this planet. The plants and animals are only a part of what biology has created. All of the oxygen in the atmosphere is attributed to biological actions. Most of the iron oxide we mine is the result of biology. Marble, limestone, and many other minerals would not exist but for biology. Because of this power, consideration of biology must be included in any analysis. Unfortunately, biology has creative ways of disregarding attempts to restrain it by mathematical formulas.
Keeling and others have observed that the CO2 seasonal cycle mirrored the growing season (May-September) when land plant photosynthesis was in full swing and the dormant season (November-April) when land plant respiration was active. Observations showed that photosynthetic drawdown appeared to occur more in North America while respiration dominated in Eurasia. The studies reported a strong inverse relationship between CO2 concentrations and annually averaged Northern hemisphere land temperatures. The average land & air temperatures could be used as a proxy to predict the biological activity, i.e. warmer periods equated to more plant growth and colder periods reflected more respiration. Proxies are valuable in explaining general biological phenomena as well as paleoecology.
One study [
It is a ratio in reflectance between visible light and near infrared. This reflectivity can be observed by satellites for a global analysis or by drones for a closer and more accurate measurement. The NDIV parameter is indeed a more accurate and valuable proxy in measuring photosynthesis (not as much on respiration) than land temperatures alone. There are many models that have been proposed for estimating leaf phenology [
However, NDIV has some limitations. The instruments cannot measure signals through clouds, and it detects canopy leaf surface area and not volume. The signal is also degraded by changes in soil reflectance, leaf optical properties, leaf orientation, viewing angle, backscattering, forward scattering, changes in humidity, and numerous other factors [
Current scientific studies support a biological connection as a predominate cause for the seasonal CO2 fluctuations. But none of these studies have explained how higher CO2 concentrations occurring at the Polar Regions can exist where there is very little land biomass. This study adds to the biological connection.
Twice as much carbon dioxide can dissolve in cold water [
A plausible explanation for this inverse relationship is that the rising/falling sea temperature does cause CO2 to be released/absorbed as Henry’s law predicts, but an off-setting phenomena must be occurring simultaneously. In this regard the sea temperature would be acting both as a source/sink and as a proxy.
A proxy is an observation/characteristic that changes in the same way that some other observation/characteristic behaves. For example, the oxygen 18 isotope contained in glacial ice cores is used to infer historical temperatures existing at the time the ice formed. The oxygen18 isotope does not cause temperature changes but it can be used to predict such changes. In this example oxygen 18 acted as a proxy.
Can ocean seasonal temperature variations be acting as a proxy?
1) Proxy―Biological Connection
The land/air temperature and CO2 relationship is inverse. Scientists used this inverse relationship as a proxy to connect CO2 from biology with land/air temperatures. This is discussed in section E subsection a. The relationship between sea temperature and phytoplankton activity may have viability, i.e. the higher temperatures increase
phytoplankton activity which in turn consumes CO2. Unfortunately, there is insufficient published data available to plot this correlation. This needs to be the subject of further scientific investigation. Until such a study is completed, this potential explanation remains unknown.
2) Proxy―Rain Connection
There is a general relationship between increasing ocean temperatures and increasing ocean rainfall [
3) Proxy―Ocean Humidity Connection
Humidity (
4) Delay Times
Delay or lag times may provide an explanation. If the sea water temperatures and CO2 concentrations are off by 6 months then the sea temperature and CO2 concentration curves are in sync. A delay or lag time is a scientifically valid mechanism. If ocean water ejects CO2 as the solubility laws project, then there would be delay with the CO2 mixing in the atmosphere. However, connecting this delay to exactly six months seems unlikely. Until a study is completed on this issue, this explanation is unknown― but questionable.
In summary, until there are plausible reasons based on sound engineering principles why atmospheric CO2 fluctuations and sea temperature fluctuations should have an inverse relationship, it should be considered scientifically viable but uncertain.
Comparison of Azores CO2 data with Midway (same latitude) over several years of relative ratios, anomalies differences, slopes, shapes, and other curve properties showed no detectible correlation with emissions. The same comparisons were done with global emissions with the same results.
A comparison was also made based on the assumption that the 1.6 ppmv yearly rise was caused entirely from CO2 emissions. This also showed no detectible correlation. A relative comparison with stations in the Southern Hemisphere, including Eastern Island (−27˚S), showed no detectible correlation.
In summary, the lack of a graphical relationship between emissions and CO2 concentrations, the fact that the Azores curve showed no measurable response to the US emissions when compared over multiple years and multiple stations, and the lack of scientific studies to the contrary, supports the conclusion that there is no likely connection between fossil fuel emissions and seasonal fluctuations.
The published studies have not adequately addressed why the highest CO2 concentrations occur at the highest latitudes, i.e. North and South Poles. There is very little biological activity at these latitudes and sea temperatures work in the opposite direction.
On the other hand, there are scientific studies connecting CO2 ejection during sea ice formation [
1) Snow Area
Snow is produced in large quantities and spread out over vast areas in the NH. The 2011 change in snow coverage averaged about 25 × 106 square km, but varied from 49 × 106 to 2 × 106 square km. Significant snow does not exist outside Antarctica due to the Southern Oceans, and as such, snow cover does not change significantly.
There is insufficient evidence that snow produces CO2 directly. However, there are valid engineering principles, which show that snow does have an indirect effect. When snow covers the ground it inhibits the soil moisture from absorbing/releasing CO2. Inhibiting absorption has the same effect as producing CO2 relative to concentration. In addition, when snow thaws the fresh snow melt quickly absorbs CO2. This snow melt then enters the ground, i.e. tundra. Therefore, snow has a significant causal connection the CO2 seasonal cycle.
2) Mass Balance
This computation is directed to whether ice formation and snow can cause enough CO2 to be released to effect a change in the atmospheric concentration. The analysis is directed to the NH because that is where the greatest fluctuation occurs. The IPCC [
The fact that it produced more than needed also suggests that there is some of the CO2 absorbed. However the absorption rate applicable to the world (98.45%) rate should not apply to the Arctic Circle. For example, this area is primarily covered by land or ice throughout the year. That restricts the ocean area available for absorption. There is no significant biomass in this area available for photosynthesis. Since these two sources/sinks are responsible for 98% of the CO2 flux, these factors will substantially reduce the amount of absorption. What absorption percentage applies is not known, but more likely than not it would be substantially less than 50%.
3) Southern Hemisphere Ice
The SH has about twice the amount of surface sea ice change each year compared to the NH. The amount was approximately 11.88 × 106 square meters in 2011. The change in sea ice was similar for each of the years and is representative. The depth of the sea ice in the SH, however, is thinner (between 1 to 1.5 meters thick) than in the NH, making the ice volume change slightly higher in the NH. The CO2 spread in the SH is very different. It is 2.5 - 3 ppmv versus 20 in the north. The volume of ice change should have produced a larger CO2 seasonal spread than observed. One explanation is that the sea ice is immediately adjacent to a large CO2 sink, i.e. the southern ocean, whereas the Arctic Circle is mostly land-locked. The southern ocean is cooler than the northern oceans and this increases it ability to absorb CO2. The release of CO2 from the ice is therefore likely absorbed by the cooler Southern Ocean.
4) Ice Boundary.
The greatest CO2 fluctuation (spread) is not at the South Pole, but closer to where the ice sheets are formed (see
5) Sea Ice & Snow Curves.
The final analysis is whether there is a good correlation between seasonal sea ice/snow and CO2 concentration. The sea ice and snow areas used in this analysis are based on 2011 data. However, as can be seen in
A geographic adjustment is applied because the snow cover extended to 30˚N latitude in the NH. At that distance, the snow would have no measurable effect on polar
fluctuations. It is also recognized that because of the Troposphere Effect, the snow at the lower latitudes would have a negligible effect. As such, the snow is divided into three groups according to the location.
The snow in group 1 (60˚N to 90˚N) will have a small effect on the CO2 in the Arctic Circle. The ice formation would have the most effect. The snow arrives earlier (mid- August) and melts later (May).
The snow in group 2 (45˚N - 60˚N) typically arrives in mid-September and continues until March. The melting process begins in March and ends in May. The snow in this group would have very little effect on the CO2 concentration in the Arctic Circle because of the mass flow vectors shown in
Snow group 3 (35˚N - 45˚N) is the furthest away from the Polar Regions. In this group the snowfall began in October and continued until January. The spring melt started in February and lasted until May. The snow in this group would have no effect on the polar regions since the group 3 distance is considerable, the troposphere volume is much higher, and the concentration flux in the northern direction would impede flow in that direction (see vector analysis in
The snow effect in this analysis only considers the freezing/absorption effects.
These figures show a correlation above 90%. A 90% correlation is exceptional and supports a good relationship. Each of the stations in the Northern Hemisphere have a sea ice & snow scale of 0 to 20 million square kilometers. The CO2 concentration may be different between stations to reflect the differences between latitudes, but the same scale of 30 ppmv was used. For example, the sea ice & snow scale in
There were a few discrepancies between the curves, which is reflected by the 90% correlation.
The lag time between the ice release of CO2 (freezing) and the concentration rise is not known, nor is the lag time known between ice melt absorbing CO2 and the drop in concentration. The small area in the Arctic Circle would likely make any time lag less
than a month. A two week time shift would affect the curves and likely increase the correlation percent. In addition, there are variables that have not been included. The Polar Cell circulates air vertically by lifting the air at 55 - 60 degree latitude and dropping it near the poles.
This would have the effect of accelerating the concentration drop while inhibiting the concentration rise. Incorporating a time lag factor and a wind factor into the curves would likely improve the correlation percent.
Each of the stations in the Southern Hemisphere used a sea ice scale of 0 to 25 million square kilometers. A slightly higher sea ice scale was used in the south because of the higher sea ice surface areas. The CO2 concentration used a scale of 6 ppmv because of the narrower spread. These same scales were used on each of the stations in the SH.
The concentrations may change between stations and between years to reflect the differences, but the same scale was applied to all. The curves were remarkably similar to those in the Northern Hemisphere except the lows and highs were flipped to reflect the season differences. The results were similar with different oceans.
The South Pole had a lower correlation (82.7% in 2014) than any of the other stations presented in the table. This was unexpected. One explanation is that the South Pole is located a considerable distance from the freezing sea ice boundary.
In sum, ice (and a small percentage of snow) is the only mechanism that can explain why the CO2 concentrations are the highest in the Polar Regions; the calculations show that such is capable of causing the 20 ppmv fluctuation in that region; and that the CO2-Sea Ice curves show a remarkable correlation. It is believed that in the remainder of the world (below 50 degrees in the north and below 40 degrees in the south) the fluctuations are governed by biological and oceanic actions.
Station | Lat. | Year | Correlation Percent | Ave % Correlation |
---|---|---|---|---|
Northern Hemisphere | ||||
Alert, Canada | 82˚N | 2014 | 94.3 | |
Alert, Canada | 82˚N | 2011 | 92.5 | |
Alert, Canada | 82˚N | 2007 | 92.0 | |
Alert Canada | 82˚N | 2000 | 90.7 | 92.4% |
Barrows, Alaska | 71˚N | 2014 | 91.9 | |
Barrows, Alaska | 71˚N | 2011 | 84.2 | |
Barrows, Alaska | 71˚N | 2007 | 91.4 | |
Barrows, Alaska | 71˚N | 2000 | 91 | 89.6% |
Iceland | 63˚N | 2014 | 87.4 | |
Iceland | 63˚N | 2011 | 90.4 | |
Iceland | 63˚N | 2007 | 92.6 | |
Iceland | 63˚N | 2000 | 91.8 | 90.6% |
Cold Bay, Alaska | 55˚N | 2014 | 92.1 | |
Cold Bay, Alaska | 55˚N | 2011 | 86.9 | |
Cold Bay, Alaska | 55˚N | 2007 | 88.8 | |
Cold Bay, Alaska | 55˚N | 2001 | 90.8 | 89.7% |
Southern Hemisphere | ||||
Palmer Station | −64˚S | 2014 | 93.6 | |
Palmer Station | −64˚S | 2011 | 93.3 | |
Palmer Station | −64˚S | 1997 | 90.2 | 92.4 |
Ushuaia, Argentina | −54.8˚S | 2014 | 88.1 | |
Ushuaia, Argentina | −54.8˚S | 2011 | 90.4 | |
Ushuaia, Argentina | −54.8˚S | 2007 | 87.3 | 88.6 |
Cape Grim, Australia | −41˚S | 2014 | 97.7 | |
Cape Grim, Australia | −41˚S | 2011 | 89.6 | |
Cape Grim, Australia | −41˚S | 2005 | 91.9 | |
Cape Grim, Australia | −41˚S | 2001 | 92.5 | 92.9 |
A Non Dispersive Infrared Analyzer (NDIR) has been used by most testing agencies to measure the atmospheric CO2 concentrations. This device only works when all of the water vapor is removed. This results in a “dry” value, which can be 10 to 15 ppmv higher than the actual value. The actual concentrations are similar to the dry values but shifted lower with the downward shift becoming larger as the latitude decreases. This downward shift can only be seen with the actual concentrations as anomalies almost entirely mask the difference. This investigation uses actual CO2 concentrations calculated from the dry values by adding water vapor back into the air using the average monthly specific humidity at each station.
Observations of the CO2 rise, swing and spread (fluctuations) were measured at many stations over multiple latitudes in both Hemispheres since 1972. Graphical analysis was done comparing CO2 concentrations with sea temperatures, fossil fuel emissions, humidity, and sea ice and snow. Various assessment techniques were used to interpret the curves and data including: R squared, correlation percent, variability, residence time, absorption percent, etc. The Troposphere effect was considered for short term observations.
Based on the observations and analysis, several conclusions were made on the causes for the CO2 “rise” (increases each year) and “spread” (seasonal fluctuations).
Several causes for the CO2 “rise” were investigated. The first one addressed was whether an increase in the ocean temperature of 0.7˚F over the last 33 years could have caused the 60 ppmv increase (128 GtC). A curve comparison (
Various causes for the CO2 “spread” (seasonal fluctuations) were investigated. The most important cause from a global standpoint is associated with biology. This has been the subject of many scientific studies as being the predominate cause for the seasonal CO2 fluctuations. This investigation agrees with those studies. However, other potential causes were considered.
Plots of sea temperature changes with CO2 concentrations showed that there was a very high inverse correlation. That is, as the temperature went up, the short term concentration went down and vice versa. This inverse relationship negates sea temperatures as the direct cause. However, it could be acting as a proxy. The types of proxy relationships include marine biology, i.e. as sea temperatures rise, phytoplankton activity increases, which causes the CO2 concentration to decline. Another proxy relationship may be rain. Rain increases with increasing temperature & humidity. The more rain, the more CO2 is scrubbed from the atmosphere, causing the CO2 concentration to drop. In addition to a proxy explanation, a six month delay between sea temperature and CO2 changes could make the two consistent. This study did not find nor investigate observational evidence to support either a proxy or a six month delay time. Based on all of these factors, a connection between changing sea temperatures and CO2 seasonal fluctuations remains uncertain.
Graphical analysis between CO2 and US fossil fuel emissions from observation stations north, south and to the west of the United States did not show a detectible connection. The Troposphere Effect coupled with actual observations negates a relationship. The fact that the NH changed at the same percentage as the SH, does not support a connection. And the lack of scientific studies connecting CO2 emissions to the seasonal fluctuations supports the conclusion that fossil fuel emissions do not cause or contribute, in any measurable way, to seasonal fluctuations. None of the potential causes discussed above provided any explanation as to why the Polar Regions have the highest CO2 concentrations.
When sea ice freezes, it ejects all of the CO2 that is contained in the water. Mathematical computations confirm that the CO2 ejected from the changes in sea ice volume was sufficient to cause a 20 degree fluctuation in the CO2 concentration in the Polar Circles. Graphical analysis at several different latitudes in the polar and near Polar Regions, for multiple years, showed a 90% correlation. Sea ice also provides a reasonable explanation as to why the highest concentration of CO2 occurs in the Polar Area. The remainder of the world (below 50 degrees in the north and below 40 degrees in the south) the fluctuations are believed to be controlled primarily by biological actions.
Nelson, M.D. and Nelson, D.B. (2016) Oceans, Ice & Snow and CO2 Rise, Swing and Seasonal Fluctuation. International Journal of Geosciences, 7, 1232-1282. http://dx.doi.org/10.4236/ijg.2016.710092