As world leaders met for the United Nations climate talks in Madrid, a Facebook post labelled efforts to reduce carbon emissions as pointless, claiming carbon emitted from volcanic eruptions have undone all human reduction strategies.
The December 13, 2019 post by an Australian user quotes Australian geologist Ian Plimer who claimed the 2010 Eyjafjallajökull volcano eruption in Iceland “negated all human efforts” to control carbon emissions in the past five years, while the 1991 Mt. Pinatubo volcanic eruption in the Philippines “emitted more greenhouse gases into the atmosphere than the entire human race had emitted in all its years on earth”.
Accompanied by an image of the 2010 Icelandic volcano eruption, the post also claims there are around 200 active volcanoes on the planet “spewing out” volcanic ash every single day and that the planet had “COOLED by 0.7 degrees in the past century”.
The post has been shared more than 390 times and has attracted more than 130 comments and 180 reactions.
The world witnessed the second largest volcanic eruption in a century when Mount Pinatubo erupted in the Philippines in June 1991, according to the US Geological Survey. The eruption spewed magma and ash into the air and produced flows of gas and hot ash down the mountain side, forcing more than 15,000 people to be evacuated.
The Facebook post refers to Professor Ian Plimer and “his book” regarding volcanic eruptions and C02 emissions. Prof Plimer’s 2009 book, Heaven and Earth, argued that humans have had a limited impact on climate, writing that “volcanoes produce more CO2 than the world’s cars and industries combined”. In 2010, he stated that “over the past 250 years, humans have added just one part of CO2 in 10,000 to the atmosphere. One volcanic cough can do this in a day”.
Dr Alistair Grinham, a volcano and greenhouse gas emissions researcher from the University of Queensland, told AAP FactCheck the 1991 Mount Pinatubo eruption only produced an estimated 0.05 gigatonnes of CO2 emissions.
“(This) is less than one day of human emissions,” Dr Grinham said.
According to the United Nations’ Emissions Gap Report in 2018 (executive summary), humans emit more than 50 gigatonnes of carbon annually, while the average annual carbon contribution from volcanoes is approximately 0.64 gigatonnes, according to a 2013 volcanic emissions review by the Mineralogical Society of America.
The Eyjafjallajökull volcano eruption in Iceland began on March 20, 2010 and was observed to be active for 95 days until June 23, 2010. The volcano was estimated to have produced a maximum of 30,000 tonnes of CO2 everyday it was active, or 0.00003 gigatonnes, according to a research report from The Macaulay Land Use Research Institute, now the James Hutton Institute, based in Scotland.
The same report said the most recent human carbon emissions figures at the time had contributed 29.2 gigatonnes of carbon dioxide to the atmosphere, meaning over the 95 day eruption period, the Icelandic volcano put about 0.00285 gigatonnes of CO2 into the atmosphere – 10,000 times less than the human emissions at the time.
Another estimate in a media report put Eyjafjallajoekull’s eruption emissions at 150,000 to 300,000 tonnes of CO2 per day. This would mean the volcano produced between 0.014 gigatonnes to 0.029 gigatonnes of carbon over the 95 day eruption period – at least 1000 times less than the annual human emissions at around that time.
Dr Grinham told AAP FactCheck the Icelandic volcano eruption was even smaller than the Philippines volcano and would not have contributed the equivalent of five years of human emissions.
“The 1991 Mount Pinatubo is one of the largest eruptions in recent times and was certainly larger than the Eyjafjallajökull 2010 eruptions,” he said.
For the claim the volcanic ash from the Eyjafjallajökull eruption had “totally erased every single effort” to reduce carbon in the atmosphere, Dr Grinham said: “The ash cloud following large eruptions events can lead to ‘global dimming’ which reduces the direct irradiance to Earth and can mask the rate of global warming. However, this dimming is a transient effect and will not offset the warming due to greenhouse gas emissions.”
Steven Sherwood, a professor of physical meteorology and atmospheric climate dynamics at the University of New South Wales, was quoted in a 2010 ABC report saying that satellite images showed the Eyjafjallajökull plume was “not thick or expansive enough to significantly affect climate”.
Claims of volcanic eruptions emitting more CO2 and negating mitigation efforts have been used previously, including a September 2019 post which falsely claimed Bali’s Mount Agung eruption had produced “more greenhouse gas in a few minutes than all of humanity since the beginning of time”.
The post also claims there are “around 200 active volcanoes on the planet” spewing out volcanic ash at any one time every day. There are about 1,500 potentially active volcanoes worldwide, according to the US Geological Survey, the scientific body which researches the earth and biological data.
According to the Mineralogical Society of America review, (page 340) there are around 150 volcanoes actively emitting C02 gasses on Earth.
The post ends by claiming the reason why people are calling it “climate change” instead of “global warming” is because “the planet has COOLED by 0.7 degrees in the past century”.
NASA’s Global Climate Change: Vital Signs of the Planet project which provides information about the Earth’s climate and environmental changes, states that for 2018, the annual global surface temperature was 0.8C above the average temperature for 1951 to 1980.
Data from the National Oceanic and Atmospheric Administration (NOAA) shows a rise in global land and ocean temperatures over the past century, while November 2019 was the second-hottest November in the 140-year global climate record.
Based on the evidence, AAP FactCheck found the Facebook post to be false. The 1991 Mount Pinatubo and 2010 Eyjafjallajökull eruptions did not put more carbon dioxide into the atmosphere than came from human emissions, according to a volcano and greenhouse gas emissions expert.
There are around 150 volcanoes actively emitting C02 gasses worldwide, not 200 as stated in the post.
A NASA report showed that in 2018 global surface temperature relative to 1951-1980 average temperatures had increased by 0.8C over the past century rather than cooling 0.7C during the same period as the post claimed.
False – The primary claim of the content is factually inaccurate.
First published December 17, 2019, 17:02 AEDT
* Update: This article was edited on December 18, 2019, at 16:54 AEDT to add a link to the UN COP 25 climate talks page in the first paragraph and to correct the date of the post in the second paragraph. (NOTE: Global time difference for the Archive.is web archive service means the archived Facebook post link appears as December 12, not December 13 as in the original Australian presentation.)
The 12th paragraph was added to add detail of a second reported estimate of the Iceland volcano’s 2010 carbon emissions.
The 21st paragraph was edited to clarify that the NASA Global Climate Change temperature increase was the anomaly for 2018, not over the past century.
The final paragraph was added to include details of global temperature rise as recorded by the NOAA.