By Dr. John Happs

Climate alarmists have attempted to dismiss the role of volcanism as a major source of global carbon dioxide whilst arguing that anthropogenic carbon dioxide is the main source and key driver of global climate change.

Volcanism, as the possible prime source of global carbon dioxide should be given closer attention since increasing numbers of research papers are highlighting the important contribution that volcanoes make in providing this life-giving gas.

Although we occasionally hear about recent well known volcanic eruptions that have interrupted aircraft schedules and encouraged people to vacate areas close to erupting volcanoes, I suspect that few people would be able to relate to few, if any, of the relatively recent eruptions such as Mount Pinatubo, El Chichon, Mount St Helens, Krakatoa or Tambora.

These examples represent modest eruptions that have disrupted lives yet there are several super-volcanoes that will inevitably erupt and cause considerable damage to infrastructure, climate and life on Earth. Super-volcano locations include the Yellowstone Caldera in North America, the Long Valley Caldera in California, the Valles Caldera in New Mexico, the Toba Caldera in Sumatra, the Taupo Caldera in New Zealand and the Aira Caldera in Japan.

Consider the many volcanoes that are currently erupting:

Geological evidence indicates that we are currently living in a volcanically quiescent period – but for how much longer? Perhaps we need to reflect on the number of active and dormant volcanoes around Indonesia alone:

Even in this current period of relatively low volcanic activity, surface and sub-surface volcanoes contribute a significant amount of life-giving carbon dioxide to the atmosphere. For instance, Iceland’s Eyjafjoell volcano releases up to 300,000 tonnes of carbon dioxide each day and this equates to the daily emissions from a medium-sized European economy.


Mount Ruapehu in New Zealand emits over 2,000 tonnes of carbon dioxide each day. That is 730,000 tonnes per year from this one quietly effusing volcano. The sum total of carbon dioxide emitted from volcanoes worldwide totally eclipses the trivial emissions from human activity.


Few people would be aware of past volcanic catastrophes that almost wiped out all life on Earth. The Permian-Triassic mass extinction that occurred around 250 million years ago eliminated over 95% of marine species and more than 70% of terrestrial vertebrates. This event can be traced back to the Siberian Traps eruption of flood basalts, covering 2 million square kilometres with the eruption lasting for more than a million years.


The Earth has experienced 5 major extinctions during the Ordovician/Silurian; the late Devonian; the Permian; the Triassic-Jurassic and the Cretaceous-Tertiary. These extreme events have been linked with asteroid strikes, massive volcanic eruptions and global cooling through the ejection of particulate material into the atmosphere and the blocking of solar radiation.

We have little hard data on the quantities of carbon dioxide emitted from the more than 80% of volcanoes that are sub-surface and it is estimated that in just a million square kilometres of the Pacific Ocean floor there are around 4,000 submarine volcanoes.

Christopher Monckton opines that:

There are thought to be some 3.5 million subsea volcanoes on Earth. So few of these volcanoes have ever been visited that we do not even know how many of them are active, let alone how much variability in their output contributes to ocean temperature change.”


Adding these sub-surface volcanoes to the more than 1,500 on land gives some idea of their potential carbon dioxide contribution.


Submarine volcanoes are poorly understood because of their inaccessibility as Dr. David Ferguson observes:

The majority of Earth’s volcanic activity occurs underwater, mostly at depths of several kilometres in the deep ocean but, in contrast to terrestrial volcanoes, even detecting that an eruption has occurred on the seafloor is extremely challenging. Consequently, there remains much for scientists to learn about submarine volcanism and its effects on the marine environment.”


How much carbon dioxide is released at these sites is unknown and generally ignored by the political/ideological Intergovernmental Panel on Climate Change (IPCC) but it is potentially a very large amount. Dr. Ian Plimer comments:

One hot spring can release far more CO2 than one 1000 mW coal-fired power station, yet they are neither seen nor measured. Submarine volcanic gas does not even figure in calculations of the sources and sinks of atmospheric CO2 in the IPCC climate models.”

(Plimer, I. (2009). Heaven and Earth: The Missing Science. Connor Court Publishing. P208.)

Researchers at Leeds University have shown that even non-erupting volcanoes, such as Iceland’s non-erupting Katla sub-glacial volcano, can release large quantities of carbon dioxide into the oceans and atmosphere.


Cardellini et al. (2011) point out that:

It has long been recognized that Earth degassing may represent a not-trivial contribution to the global CO2 budget.”

(Geophysical Research Abstracts Vol. 13, EGU2011-7778-1)

Koepenick et al. (1996) agree, saying:

The relatively large CO2 fluxes measures for alkaline volcanoes such as Oldoinyo Lengai or Etna may indicate that midplate volcanoes represent a large, yet relatively unknown natural source of CO2.”

(Journal of Geophysical research. Vol.101. No B6, pp 13,819-13,830)

Dr. David Lund from the Department of Marine Sciences at the University of Connecticut and his colleagues studied hydrothermal activity along the mid-ocean ridge system. They suggest that the release of hot molten rock, or magma, from beneath the Earth’s crust plays a significant role in the Earth’s climate, attributed to the release of heat and carbon dioxide into the deep ocean.


The potentially huge supplies of surface and sub-surface volcanic carbon dioxide are typically ignored by climate alarmists. They would rather focus on the trivial input of anthropogenic carbon dioxide.

Dr. John Happs M.Sc.1st Class; D.Phil. John has an academic background in the geosciences with special interests in climate, and paleoclimate. He has been a science educator at several universities in Australia and overseas and was President of the Western Australian Skeptics for 25 years.


  1. It seems to me that volcanoes and hydrothermal vents have been around forever. There has been no massive increase in volcanic activity, so a sudden increase over a very short term in itself would suggest an alternative explanation.
    What is this rubbish about?

    1. That appears to be a rather partisan comment, Vince.
      Partisan, ADJECTIVE: prejudiced in favour of a particular cause.
      ‘What is this rubbish about?’ You wouldn’t call that an expression reflecting a scientific approach, would you?
      Yes, we can presume that volcanoes and hydrothermal vents have been around for geological time-scales but we can’t assume that there ‘has been no massive increase in volcanic activity’, simply because we don’t have the data. That’s the point of ‘this rubbish’, surely?
      If we re-read the last paragraph (and exclude the emotive term ‘trivial’) we see that those wishing to alarm us, and that they do, focus on, at base, the make-work (my belief) avenue of anthropogenic carbon dioxide, and only that.
      Can you imagine a conventional science-trained research team asking their superiors for funding for exploration of non-anthropogenic causes of the ‘heating emergency’? I can imagine they would be immediately branded as outliers, people who are acting ridiculously, contrary to received opinion, and a group who should be eased aside and out. Ostracised. If you can’t, I suspect a partisan, unscientific, perspective.
      Cancel culture is abroad, and vital.

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