Commentary: Underestimating natural forces

The climate change argument continues with one side proclaiming the issue is resolved and the more skeptical challenging the hyper-charged claims of imminent doom if we don’t radically alter our way of life immediately. It is unfortunate that the issue has been so highly politicized, especially by strident environmentalists claiming to hold the moral high-ground and demanding that all dissent be crushed, silenced, shamed into retreat.

A few weeks ago one letter writer suggested that volcanoes played a significant role in altering the climate, to be rebuffed by another writer stating emphatically that volcanic activity was an insignificant factor, pointing out that the Mt. Saint Helens eruption quoted by the previous writer emitted an insignificant amount of carbon dioxide (CO2) gas compared to that of human-generated (anthropogenic) emissions. I would say, not so fast, there are many other factors involved; natural forces cannot be dismissed out-of-hand as a significant contributor to our changing climate. I have argued in the past that much of the current observations of climate change is a consequence of natural forces and cycles and continue to assert as much now.

The eruption of Mt. Saint Helens was not a major contributor of CO2 emissions affecting climate as one writer pointed out but other volcanoes have in the past have had dramatic effects on the climate, especially when clusters of eruptions occur. New research (2016-2017) on Icelandic subglacial volcanoes which were not previously considered to any great degree are now being looked at as possible major emitters of CO2. The Katla volcano in Iceland emits 12-24 kilotons of CO2 per day, double that of previous estimates.

Another factor is the location of the volcano; eruptions occurring in the tropics near the equator pose a much greater threat to global climate than eruptions occurring in the temperate locales due to the planetary circulation system that carries their ash and gasses around the globe with negative effects. Mt. Pinatubo “reached 40 kilometers into the atmosphere and ejected 17 megatons of Sulfur Dioxide (SO2), circled the globe in three weeks and produced global cooling in the Northern Hemisphere by up to 0.6 degrees Centigrade during 1992-1993. It also contributed to an accelerated rate of ozone depletion during that same period.” (Geophysical Research Letters, Terri Cook, 8 November 2018). “Over the next 15 months scientists measured a drop in the average global temperature of about 21 degree F (0.6 degrees C).” (NASA Earth Observatory, Global Effects of Mount Pinatubo, 6/15/2001.)

The spectacular eruption of Krakatoa in the Sunda Strait in August, 1883 ejected about 20 cubic kilometers of debris almost 40 kilometers high into the atmosphere, with fine particles traveling west, circling the globe several times over the course of two years, cooling the atmosphere while producing globally spectacular sunsets. Krakatoa was several orders of magnitude greater than the eruption of Mt. Saint Helens, (listed as a VEI-5 on the Volcanic Explosivity Index, which ejected about 1 cubic kilometer of material) with Krakatoa being listed as a VEI-6. By comparison, Krakatoa was dwarfed by the 1815 eruption of Tambora, also located in Indonesia and was the largest volcanic eruption in the last 10,000 years. Its eruption was listed as a VEI-7 and it ejected over 150 cubic kilometers of material. The only volcanoes larger than Tambora are supervolcanic eruptions (VEI-8) which eject at least 1000 cubic kilometers of material. There are three known supervolcanoes: Yellowstone in Wyoming, Taupo in New Zealand and Toba in Indonesia. The last major eruption of a supervolcano took place before historical records exist, approximately 26,000 years ago.

Tambora’s effect on the climate was spectacular and deadly for the globe. It reduced global temperatures 0.7 – 1.3 degrees F which equals the impact of all man-made climate change to date. Of all the volcanic eruptions by volume since 1800, Tambora accounts for almost 2/3 of the total volume and includes 60 megatons of sulfur dioxide ejected into the stratosphere, which caused an average drop in northern hemisphere temperatures of 5.4 degrees F. The year 1815-16 was called “the year without a summer,” produced snow in New England in June, prolonged, frost throughout the summer in northern latitudes, overcast, gloomy skies in Europe and global famine, disease and civil disorder. (The gloomy weather also inspired Mary Shelley to write the horror novel Frankenstein while “summering” at Lake Geneva, Switzerland.) Tambora’s eruption had the explosive equivalent of an 800 megaton thermonuclear explosion. The largest man-made nuclear device was built by the former Soviet Union/Russia (the “Tsar Bomba”) during the Cold War and was rated at 50 megatons. The United States’ largest nuclear detonation conducted at the Pacific Test Site and was about 10 megatons. The Hiroshima bomb was rated at about 0.2 megatons. Tambora dwarfed them all and registered an estimated 9.5 on the earthquake Richter Scale, larger than any known and recorded earthquake.

Climate alarmists are quick to discount natural forces such as volcanic activity, preferring human causes as explanations to increases in CO2 and climate extremes. Our climate is complex and often violent. Atmospheric River storms, (ARK storms) such as the 1862 megaflood in California would be ascribed to manmade climate change today, although CO2 emissions were negligible at that time. That storm dumped 10 feet of rain and snow on the Central Valley and the Sierras in 43 days, creating an inland sea 300 miles long and 60 miles wide, bankrupting the new State of California. Geological records show such storms occurred nine other times in California between AD 212 and AD 1862 with a 50-50 chance of another such storm occurring before 2060. Keep your life-jacket handy.

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