CO2 Emissions from Submarine Volcanic Activity and ‘Capture and Storage’ of CO2 in Carbonate Bearing Sediments

By Jacob Rebek
7 December 2018

CO2 emissions from volcanic activity are orders of magnitude greater than those caused by humans burning fossil fuels.

Submarine volcanic activity is orders of magnitude greater than subaerial volcanic activity but it was ‘out of sight and out of mind’ until results of studies of sea/ocean floor commenced in 1950’s. Geologists are aware of importance of submarine volcanic activity in global CO2 ‘supply and demand’ balance. However, climate scientists contributing to IPCC reports are still ignoring the importance of CO2 emissions from submarine volcanic activity.

Marie Tharp and Bruce Heezen created the first accurate map of the sea/ocean floor, a project they started in the 1950’s. This map was published in 1980, but is still relevant today. In addition to volcanic activity along mid-sea/oceanic ridges, there is volcanic activity elsewhere on sea/ocean floor (including islands if the volcanic cone is high enough) and along some of the margins of sea/oceans.

Even with the latest sea/ocean floor exploration technology, it is difficult to make systematic measurements of CO2 emissions from submarine volcanic activity. Below an alternative way for estimating CO2 emissions from submarine volcanic activity is discussed.

Geologic science commenced with study of sedimentary strata (notably limestone and chalk strata) and fossils in United Kingdom, including the White Cliffs of Dover. Litho-stratigraphic studies made great progress – notably due to drilling for oil and gas – so that now all sedimentary strata accumulated in all seas/oceans throughout geologic history are now reasonably well known.

Carbonate bearing strata represent a significant proportion of all sedimentary strata.

Algae called coccoliths absorbed CO2 from seawater and made their calcium carbonate shells which accumulated on sea floor.

Throughout geologic history, CO2 was being stored in carbonate bearing sedimentary strata – notably in limestones (which consist of calcium carbonate containing 56% CaO and 44% CO2), dolomites (which consist of calcium magnesium carbonate containing 30% CaO, 22% MgO and 48% CO2), marls (a mixture of calcium carbonate and silicate grains), in fine grained dolomitic sediments (a mixture of calcium magnesium carbonate and silicate grains) and in sandstones with limestone and dolomite grains.

In a zone extending from the Alps through the mountains of central Asia to China, the overall thickness of limestone and dolomite beds is several thousand metres, representing very large quantities of CO2 that was extracted by organisms from sea/ocean water and incorporated in the sediment on sea/ocean floor in Mesozoic period over a period of about 200 million years. Increased CO2 emissions from submarine volcanic activity are considered to be the main reason for accumulation of great thickness of carbonate bearing sediments in Mesozoic period.

In addition to activity of organisms extracting CO2 from sea/ocean water, activity of plants described as photosynthesis which extracts CO2 from air or water and burial of dead plants in sedimentary strata is operating on large scale.

In other words, – photosynthesis is the second natural process for ‘capture and storage’ of CO2 in sedimentary strata process and is responsible for formation of fossil fuel deposits.

To appreciate the scale of this second very important natural process, one needs to take into account the fact that economic fossil fuel deposits represent only a fraction of total organic matter that has been ‘captured and stored’ in sediments.

In billions of years of geological history, very large volumes of sediments have accumulated on sea/ocean floor and have been added to Earth’s Crust and most of them contain concentrations of calcium and calcium magnesium carbonate as well as organic carbon.

Some of the sedimentary strata has been subjected to uplift that resulted on mountains and has been partly eroded and redeposited in seas/ oceans, however, a much larger proportion of sediments has been preserved on long term basis so that sedimentary strata represent a very effective ‘capture and store’ system for the CO2 that is being emitted in the course of volcanic activity.

In certain geologic periods, much greater thicknesses of carbonate bearing sediments and sediments containing relatively abundant organic matter (for example ‘oil shales’) have been deposited than in other periods. Sediments with higher content of carbonates are in most cases characterised by higher content of organic matter (for example ‘oil shales’ and oil deposits in Persian Gulf which are hosted in carbonate bearing sedimentary series).

Major changes in activity of organisms extracting CO2 from water and air were due to major changes in concentrations of CO2 in water and air which were largely due to major changes in rate of CO2 emissions from submarine volcanic activity.

In conclusion, in global CO2 ‘supply and demand’ equation, key factors are:

  • CO2 emissions from submarine volcanic activity
  • organisms extracting CO2 from water and air which are ‘captured and stored’ in sediments on sea/ocean floor.

Natural changes in global CO2 ‘supply and demand’ are orders of magnitude greater than CO2 emissions caused by humans burning fossil fuels.

If, hypothetically, all of the CO2 contained in atmosphere was dissolved on sea/ocean waters and then used up by organisms that are responsible for deposition of carbonate bearing sediments, only a few millimetres of limestone would be added to the very thick accumulation of sediments on sea/ocean floor.

Since CO2 emissions caused by humans burning fossil fuels represent only a fraction of total CO2 contained in atmosphere, only a slight increase in activity of organisms that are extracting CO2 from water and air would be sufficient to ‘capture and store’ all of the CO2 emissions caused by burning of fossil fuels.

Geological studies of climate and life on Earth lead to conclusion that changes are cyclical and that up till now a balance has been restored in every cycle.

Due to relatively very small quantity of CO2 emissions caused by burning of fossil fuels when compared with quantity of emissions from submarine volcanoes, the balance will also be restored in current cycle.

The sea/ocean waters contain 80 times more CO2 than atmosphere so that changes in concentrations of CO2 in atmosphere and climatic changes largely depend on processes in oceans and seas.

On geological timescale, there are is an overall trend of changes in climate and sea levels. Life on Earth undergoes evolution by adaptation to cyclical changes and to the overall trend of change, as first proposed by Charles Darwin.

Changes are natural and adaptation to changes is the essence of life. Therefore, the proclaimed need to prevent climate change does not make sense.

The conclusions are that:

    1. CO2 emissions from submarine volcanic activity are orders of magnitude greater than those caused by humans burning fossil fuels.
    2. Quantities of CO2 ‘captured and stored’ in sedimentary strata being accumulated on sea/ocean floor are orders of magnitude greater than quantities of CO2 emissions caused by humans burning fossil fuels.
    3. Cyclical changes due to natural processes are orders of magnitude greater than changes due to human activities.
    4. The impact of human activity on global climate and sea levels is insignificant if compared with cyclical changes due to natural processes that have been operating throughout geologic history.

Jacob Rebek
Geologist
90/5 Woodlands Ave.
Breakfast Point, NSW 2137
jrebek@bigpond.com

2 thoughts on “CO2 Emissions from Submarine Volcanic Activity and ‘Capture and Storage’ of CO2 in Carbonate Bearing Sediments”

  1. During the last 30 years the use of instruments in the world ocean has enabled the US NODC (National Oceanographic Data Centre) to issue in 2017 curves of the World Oceans the “vertical mean temperature anomaly 0-700m depth. They gave graphs at 3-month intervals of the 39-month average on the base period of 1955-2010.

    When these figures were plotted against yearly plots of the Carbon dioxide (CO2) levels in the atmosphere as measured at the Mauna Loa Observatory a dead straight line was obtained from 1990 to 2015.

    If a plot like that had been made from experimental evidence in the laboratory one would look for evidence of fiddling the figures. There is little doubt that the ocean temperatures and the level of CO2 in the atmosphere are linked. If you know one you will know the other. It seems that the oceanic temperature measurement organisation could very well be scrapped as measurement of CO2 levels is easy.

    The curves do show an interesting trend. It seems that the rate of warming of the oceans is increasing. The rate of warming is now 3 times that at the start of the measurements which were evidently very inaccurate. Looking for a reason for the warming it is found that the rate of oceanic circulation is slowing down. Possibly this is due to the under water melting of the Western and largely floating Antarctic ice. The reduction in salinity of the sea would reduce the amount of dense salty cold water falling to the ocean depths during the winter formation of the sea-ice-sheet and hence reduce the oceanic circulation. That the oceans are not being cooled down at the former rate helps to explain the increasing climate warming that is, mistakenly, blamed on the burning of fossil fuels. It would be putting the cart before the horse to suggest that CO2 level in the atmosphere is the cause of the ocean warming.

    Since the climate shift seems to reduce rainfall it would be desirable to have cheap electric power to desalinate water or take other steps to increase water supply. Using the cheapest fuels available means coal for sure and this will require nations to take the lead.

  2. Over the past 20 to 30 years diving buoys have been used to accurately measure the world ocean temperatures from the surface down to 700m deep. A graph of the 2017 NODC mean ocean temperature trend curve plotted against the atmospheric CO2 levels measured at Mauna Loa results is a straight line. This shows that the seawater temperature and CO2 levels are linked. If you know the one you know the other.
    There can be little doubt that the mean ocean temperature controls the CO2 levels and it has nothing to do with the CO2 released from fossil fuel burning.
    This political claim is deliberate and false with the intent, inter alia, to prevent improving the standard of living of the undeveloped countries. It is also strongly affecting the economy of those countries that have acted on the claim.
    The large CO2 emissions detailed in Jacob Rebek’s article may well greatly exceed our CO2 emissions but the volcanic activity heating seems to be minor compared with the warming from the Sun. The idea that we can control the climate by reducing our fuel use is ludicrous as highlighted by my plot.
    The CO2 levels have been increasing (and the ocean temperatures) over the last half a century. They reflect the high solar activity of the period. My plot of “Temperature versus CO2” also clearly shows that the warming rate has speeded up markedly. This is countering the cooling phase that must have started because of the reduction in the solar activity.
    Melting from underneath of the Western Antarctic ice lobe by warm Pacific waters is blamed for the observed slowing down of the oceanic water circulation. This is reducing the normal oceanic cooling and will probably mean the little ice age predicted for 2030-2040 by Nils-Axel Mörner (and others) will not be so deep and may only reduce the rate of the rising trend

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