Posts Tagged ‘Carbon dioxide in Earth’s atmosphere’

Carbon Cycle still has many uncertainties

June 20, 2013

How much of the increase in carbon dioxide concentration in the atmosphere is due to the use of fossil fuels is not as certain as many would like to believe. The role of the oceans both in the emission and the absorption of carbon dioxide is far from being understood or quantified. Emissions due to fossil fuel combustion are of the same magnitude as just the error band surrounding the emissions from the oceans and  from the emissions due to transpiration. The primary sources of carbon dioxide in the atmosphere are the oceans and transpiration. The assumption that these emissions are in balance with the absorption by the oceans and plant life is just an assumption based on an assumed equilibrium which is far from certain. I posted a few weeks ago

…. The general assumption is that about 40% of man-made carbon dioxide shows up as this increase with the remainder being absorbed by the enhanced action of sinks.


The justification for this conclusion is supported by measurements of the falling proportion of  13C  in the atmosphere which is taken to signal the appearance of CO2 from fossil fuel emissions. …… 

The correlation of changes in δ13C with ENSO events and the comparison with a simple model of a series of cascades suggest that the changes in δ13C in the atmosphere have little to do with the input of CO2 emissions from the continuous use of fossil fuels.

Even though the combustion of fossil fuels only contributes less than 4% of total carbon dioxide production (about 26Gt/year of 800+GT/year), it is usually assumed that the sinks available balance the natural sources and that the carbon dioxide concentration – without the effects of man – would be largely in equilibrium.  (Why carbon dioxide concentration should not vary naturally escapes me!). It seems rather illogical to me to claim that sinks can somehow distinguish the source of carbon dioxide in the atmosphere and preferentially choose to absorb natural emissions and reject anthropogenic emissions! Also, there is no sink where the absorption rate would not increase with concentration.

Carbon dioxide emission sources (GT CO2/year)

  • Transpiration 440
  • Release from oceans 330
  • Fossil fuel combustion 26
  • Changing land use 6
  • Volcanoes and weathering 1

Carbon dioxide is accumulating in the atmosphere by about 15 GT CO2/ year. The accuracy of the amounts of carbon dioxide emitted by transpiration and by the oceans is no better than about 2 – 3% and that error band (+/- 20GT/year)  is itself almost as large as the total amount of emissions from fossil fuels. ….. 

Two new papers – in completely different fields – highlight the uncertainty in carbon dioxide emissions from the oceans and from plant and animal life:

1. Interannual variability in sea surface temperature and fCO2 changes in the Cariaco Basin Y.M. Astor et al, Deep-Sea Res. II (2013),

The Hockey SchtickA new paper published in Deep-Sea Research finds the ocean is a net source of CO2 to the atmosphere, the opposite of claims by climate alarmists that the ocean removes CO2 from the atmosphere. According to the authors, “At the [research] site, the ocean is primarily a source of CO2 to the atmosphere, except during strong upwelling events.” The paper also notes, “Astor et al.(2005) observed the interactions between physical and biochemical parameters that lead to temporal [over time] variations in fCO2 [CO2 flux from the] sea, finding that even during periods of high production, the CO2 flux between the ocean and the atmosphere decreased but remained positive, i.e. CO2 escaped from the ocean to the atmosphere.” 

The paper corroborates prior work by SalbyHumlum et alFrölicher et alCho et alCalder et alFrancey et alAhlbeckPetterssonand others demonstrating that man-made CO2 is not the driver of atmospheric CO2. This new work confirms the primary source of atmospheric CO2 is out-gassing from the oceans, which is due to decreased solubility with increased temperature.

2. Michael S. Strickland, Dror Hawlena, Aspen Reese, Mark A. Bradford, and Oswald J. Schmitz. Trophic cascade alters ecosystem carbon exchangePNAS, 2013 DOI:10.1073/pnas.1305191110

EurekAlert: …. The study, conducted by researchers at the Yale School of Forestry & Environmental Studies, comes out this week in the Proceedings of the National Academy of Sciences. It looks at the relationship between grasshoppers and spiders—herbivores and predators in the study’s food chain—and how it affects the movement of carbon through a grassland ecosystem. Carbon, the basic building block of all organic tissue, moves through the food chain at varying speeds depending on whether it’s being consumed or being stored in the bodies of plants. However, this pathway is seldom looked at in terms of specific animal responses like fear from predation. …… 

….. The study found that the presence of spiders drove up the rate of carbon uptake by the plants by about 1.4 times more than when just grasshoppers were present and by 1.2 more times than when no animals were present. It was also revealed that the pattern of carbon storage in the plants changed when both herbivores and carnivores were present. The grasshoppers apparently were afraid of being eaten by the spiders and consumed less plant matter when the predators were around. The grasshoppers also shifted towards eating more herbs instead of grass under fearful scenarios.

At the same time, the grasses stored more carbon in their roots in a response to being disturbed at low levels when both herbivores and carnivores were present. In cases where only herbivores were present, the plants stored less carbon overall, likely due to the more intense eating habits of the herbivores that put pressure on plants to reduce their storage and breathe out carbon more. These stress impacts, then, caused both the plants and the herbivores to change their behaviors and change the composition of their local environment.

Carbon dioxide concentration was at 500+ ppm already in 1860

May 13, 2013

This has been around for some time, but I have only just come across it.

It could be that GS Callendar’s 1957 paper about Global warming  cherry picked supportive data points and ignored inconvenient data.

Reblogged from JunkScience

Did one of the fathers of manmade global warming cherry-pick his data for a 1957 study?

Here’s the original data.

Source: Slocum, G., Has the amount of carbon dioxide in the atmosphere changed significantly since the beginning of the twentieth century? Month. Weather Rev., 1955(October): p. 225-231.

Source: Slocum, G., Has the amount of carbon dioxide in the atmosphere changed significantly since the beginning of the twentieth century? Month. Weather Rev., 1955(October): p. 225-231. 

Here’s the cherry-picked version.

Callendar graph

Read the full story at Tallbloke’s blog.


slocum 1955 carbon dioxide Slocum, G., Has the amount of carbon dioxide in the atmosphere changed significantly since the beginning of the twentieth century? Month. Weather Rev., 1955(October): p. 225-231. 

Climate Change: Incorrect information on pre-industrial CO2

CO2: The Greatest Scientific Scandal of Our Time



Disconnect between man-made CO2 and atmospheric levels of CO2

April 28, 2013

The evidence grows that

  1. Temperature drives carbon dioxide, and 
  2. man made carbon dioxide is a minor contributor to carbon dioxide concentration in the atmosphere

Atmospheric verification of anthropogenic CO2emission trendsRoger J. Francey et al, Nature Climate Change 3, 520–524 (2013) doi:10.1038/nclimate1817

The Hockey Schtick reports:

A recent paper published in Nature Climate Change finds a disconnect between man-made CO2 and atmospheric levels of CO2, demonstrating that despite a sharp 25% increase in man-made CO2 emissions since 2003, the growth rate in atmospheric CO2 has slowed sharply since 2002/2003. The data shows that while the growth rate of man-made emissions was relatively stable from 1990-2003, the growth rate of atmospheric CO2 surged up to the record El Nino of 1997-1998. Conversely, growth in man-made emissions surged ~25% from 2003-2011, but the growth rate of atmospheric CO2 has flatlined since 1999 along with global temperatures. The data demonstrates temperature drives CO2 levels due to ocean outgassing, man-made CO2 does not drive temperature, and that man is not the primary cause of the rise in CO2 levels.

Global temperature dependence on CO2 concentration goes missing

September 12, 2012

That climate changes and will continue to change is obvious. That this is primarily due to solar effects via the oceans also seems obvious to me. It seems the height of arrogance when – like Canute attempting to hold back the tides – climate-politicians attempt to hold back the sun and its effects. The sun cannot be carbon-taxed into submission.

That CO2 concentration in the atmosphere has little impact on climate is the reality that climate-politicians continue to deny. That the effects of man-made carbon dioxide emissions are of even less significance is becoming increasingly obvious.

Over the last 16 years global temperatures have been pretty flat (actually the trend is very slightly downwards). During this same time  the atmospheric mean CO2 concentration has continued its increasing trend of between 1.5 and 2.5 ppm /year.

The data show no causality between CO2 concentration  and global mean temperature. How much or how little man-made emissions of CO2 contribute to the global mean concentration is still open to much question.

Global mean temperatures from

Global temperature anomaly hardcrut3vgl (via

The following plot of mean annual atmospheric CO2 concentrations is from NOAA data 



Carbon dioxide lags temperature

September 3, 2012

A new paper again confirming that the theory that carbon dioxide leads global temperature is misconceived.

” Changes in global atmospheric CO2 are lagging 9.5-10 months behind changes in global air surface temperature. CO2 released from use of fossil fuels have little influence on the observed changes in the amount of atmospheric CO2.” 

The phase relation between atmospheric carbon dioxide and global temperature

by Ole HumlumKjell StordahlJan-Erik Solheim, Global and Planetary Change


Using data series on atmospheric carbon dioxide and global temperatures we investigate the phase relation (leads/lags) between these for the period January 1980 to December 2011. Ice cores show atmospheric CO2variations to lag behind atmospheric temperature changes on a century to millennium scale, but modern temperature is expected to lag changes in atmospheric CO2, as the atmospheric temperature increase since about 1975 generally is assumed to be caused by the modern increase in CO2. In our analysis we use eight well-known datasets; 1) globally averaged well-mixed marine boundary layer CO2 data, 2) HadCRUT3 surface air temperature data, 3) GISS surface air temperature data, 4) NCDC surface air temperature data, 5) HadSST2 sea surface data, 6) UAH lower troposphere temperature data series, 7) CDIAC data on release of anthropogene CO2, and 8) GWP data on volcanic eruptions. Annual cycles are present in all datasets except 7) and 8), and to remove the influence of these we analyze 12-month averaged data. We find a high degree of co-variation between all data series except 7) and 8), but with changes in CO2 always lagging changes in temperature. The maximum positive correlation between CO2 and temperature is found for CO2 lagging 11–12 months in relation to global sea surface temperature, 9.5-10 months to global surface air temperature, and about 9 months to global lower troposphere temperature. The correlation between changes in ocean temperatures and atmospheric CO2 is high, but do not explain all observed changes.


► The overall global temperature change sequence of events appears to be from 1) the ocean surface to 2) the land surface to 3) the lower troposphere.

►Changes in global atmospheric CO2 are lagging about 11–12 months behind changes in global sea surface temperature.

► Changes in global atmospheric CO2 are lagging 9.5-10 months behind changes in global air surface temperature. Changes in global atmospheric CO2 are lagging about 9 months behind changes in global lower troposphere temperature.

► Changes in ocean temperatures appear to explain a substantial part of the observed changes in atmospheric CO2 since January 1980.

► CO2 released from use of fossil fuels have little influence on the observed changes in the amount of atmospheric CO2, and changes in atmospheric CO2 are not tracking changes in human emissions.

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