June 15 2021 — 30 years ago, the volcano exploded in the second-largest volcanic eruption on Earth in the 20th century. Follow us on Twitter: @INTEL_TODAY
About 15 million tons of sulfur dioxide were injected into the stratosphere in Pinatubo’s 1991 eruptions, and dispersal of this gas cloud around the world caused global temperatures to drop temporarily (1991 through 1993) by about 1°F (0.5°C).
Pinatubo injected about 15 million tons of sulfur dioxide into the stratosphere, where it reacted with water to form a hazy layer of aerosol particles composed primarily of sulfuric acid droplets. Over the course of the next two years strong stratospheric winds spread these aerosol particles around the globe.
Unlike the lower atmosphere (or troposphere, which extends from the surface to roughly 10 km), the stratosphere does not have rain clouds as a mechanism to quickly wash out pollutants.
Therefore, a heavy influx of aerosol pollutants, like the plume from Mount Pinatubo, will remain in the stratosphere for years until the processes of chemical reactions and atmospheric circulation can filter them out. In the case of Mount Pinatubo, the result was a measurable cooling of the Earth’s surface for a period of almost two years.
Because they scatter and absorb incoming sunlight, aerosol particles exert a cooling effect on the Earth’s surface. The Pinatubo eruption increased aerosol optical depth in the stratosphere by a factor of 10 to 100 times normal levels measured prior to the eruption. (“Aerosol optical depth” is a measure of how much light airborne particles prevent from passing through a column of atmosphere.)
Consequently, over the next 15 months, scientists measured a drop in the average global temperature of about 1 degree F (0.6 degrees C). [NASA Langley Research Center]
Global Trends (The Strategic Futures Group — National Intelligence Council — March 2021)
The last issue of Global Trends (The Strategic Futures Group — National Intelligence Council — March 2021) has several long sections on Global Warming.
One of them — Calls for Geoengineering — caught my attention.
“As warming gets closer to exceeding the Paris Agreement goals, it is increasingly likely that states and nonstate actors will more aggressively research, test, and possibly deploy geoengineering measures—deliberate large-scale interventions in the earth’s natural systems— to try to counteract climate change.
Current research is largely focused on solar radiation management (SRM), an effort to cool the planet by reflecting the suns energy back into space. Stratospheric aerosol injection (SAI), a form of SRM that sprays particles in the stratosphere to cause global dimming, has attracted funding by those who fear the worst of climate change.
Proponents argue that the needed energy transformation will happen too slowly and that SAI can buy the planet time because it is technologically feasible and less expensive than mitigation.”
Current research is almost entirely in computer models with academia, nongovernmental organizations, and private companies playing a leading role. However, there will be increased calls for countries to begin engaging in the dialogue and possibly take leadership to develop international agreements that could help set research standards, ensure transparency in live tests, determine the legal framework around if, how, and when to deploy SRM technologies, and monitor the effects.
The possibly catastrophic unintended side effects are not well understood, and some scientists fear that SRM, while keeping temperatures down, would create unexpected and devastating changes in weather systems and rainfall patterns.
Countries and nonstate actors deploying it alone will increase the risk of conflict and blowback, especially when others blame them for a disaster they believe was caused by geoengineering.
The readers familiar wit this blog certainly noticed the word “blowback” which is straight from the CIA lexicon.
A recent analysis finds that cooling the Earth enough to eliminate roughly half of warming, rather than all of it, generally would not make tropical cyclones more intense or worsen water availability, extreme temperatures or extreme rain.
The conclusion of that paper published in Nature Climate change — Halving warming with idealized solar geoengineering moderates key climate hazards — reads:
“It would be premature to conclude from this study that no region would experience greater aggregate climate risks in a real-world deployment of SG [Sun Geoengineering] that halved anthropogenic warming, as we analysed an idealized scenario and a limited set of climate variables.
Our results do not, however, support the common claims that SG would inevitably lead to significant harms to some regions, nor the claims that SG’s benefits and harms always have a strongly unequal distribution.”
As Al Pacino would say: “I am over-fucking-whelmed.”
Can a volcanic eruption change the course of History?
The 1783-1784 Laki eruptions had widespread effects and long-lasting consequences.
In the months after the eruption, a strange haze covered the sky above Europe, making breathing difficult. As the ash and gases from the eruption entered the high layers of the atmosphere, they absorbed moisture and sunlight, changing the climate for years to come.
From 1783 to 1785 accounts from both Japan and America describe terrible droughts, exceptional cold winters, and disastrous floods. In Europe, the exceptionally hot summer of 1783 was followed by long and harsh winters.
The resulting crop failures may have triggered one of the most famous insurrections of starving people in history, the French Revolution of 1789-1799. [FORBES]
Darkness by Lord Byron
“Darkness” is a poem written by Lord Byron in July 1816 on the theme of an apocalyptic end of the world.
That year was known as the Year Without a Summer, because Mount Tambora had erupted in the Dutch East Indies the previous year, casting enough sulphur into the atmosphere to reduce global temperatures and cause abnormal weather across much of north-east America and northern Europe. [Wikipedia]
I had a dream, which was not all a dream.
The bright sun was extinguish’d, and the stars
Did wander darkling in the eternal space,
Rayless, and pathless, and the icy earth
Swung blind and blackening in the moonless air;
Morn came and went—and came, and brought no day
Remembering Mount Pinatubo 25 Years Ago: Mitigating a Crisis — USGS
30 Years Ago — Remembering Mount Pinatubo (June 15 1991)