Toba volcano super eruption destroyed the ozone layer and caused a human population bottleneck

Author(s):  
Sergey Osipov ◽  
Georgiy Stenchikov ◽  
Kostas Tsigaridis ◽  
Allegra LeGrande ◽  
Susanne Bauer ◽  
...  

<p>Volcanic eruptions trigger a broad spectrum of climatic responses. For example, the Mount Pinatubo eruption in 1991 forced an El Niño and global cooling, and the Tambora eruption in 1815 caused the "Year Without a Summer." Especially grand eruptions such as Toba around 74,000 years ago can push the Earth's climate into a volcanic winter state, significantly lowering the surface temperature and precipitation globally. Here we present a new, previously overlooked element of the volcanic effects spectrum: the radiative mechanism of stratospheric ozone depletion. We found that the volcanic plume of Toba enhanced the UV optical depth and suppressed the primary formation of stratospheric ozone from O<sub>2</sub> photolysis. Sulfate aerosols additionally reflect the photons needed to break the O<sub>2</sub> bond (λ < 242 nm), otherwise controlled by ozone absorption and Rayleigh scattering alone during volcanically quiescent conditions. Our NASA GISS ModelE simulations of the Toba eruption reveal up to 50% global ozone loss due to the overall photochemistry perturbations of the sulfate aerosols. We also consider and quantify the radiative effects of SO<sub>2</sub>, which partially compensated for the ozone loss by inhibiting the photolytic O<sub>3</sub> sink.</p><p>Our analysis shows that the magnitude of the ozone loss and UV-induced health-hazardous effects after the Toba eruption are similar to those in the aftermath of a potential nuclear conflict. These findings suggest a “Toba ozone catastrophe" as a likely contributor to the historic population decline in this period, consistent with a genetic bottleneck in human evolution.</p>


2021 ◽  
Author(s):  
Claire Lamotte ◽  
Jonathan Guth ◽  
Virginie Marécal ◽  
Giuseppe Salerno ◽  
Nicolas Theys ◽  
...  

<p><span>Volcanic eruptions are events that can eject several tons of material into the atmosphere. Among these emissions, sulfur dioxide is the main sulfurous volcanic gas. It can form sulfate aerosols that are harmful to health or, being highly soluble, it can condense in water particles and form acid rain. Thus, volcanic eruptions can have an environmental impact on a regional scale.</span></p><p><span>The Mediterranean region is very interesting from this point of view because it is a densely populated region with a strong anthropogenic activity, therefore polluted, in which Mount Etna is also located. Mount Etna is the largest passive SO<sub>2</sub> emitter in Europe, but it can also sporadically produce strong eruptive events. It is then likely that the additional input of sulfur compounds into the atmosphere by volcanic emissions may have effects on the regional atmospheric sulfur composition.</span></p><p><span>We are particularly investigating the eruption of Mount Etna on December 24, 2018 [Corradini et al, 2020]. This eruption took place along a 2 km long breach on the side of the volcano, thus at a lower altitude than its main crater. About 100 kt of SO<sub>2</sub> and 35 kt of ash were released in total, between December 24 and 30. With the exception of the 24th, the quantities of ash were always lower than the SO<sub>2.</sub></span></p><p><span>The availability of the TROPOMI SO<sub>2</sub><sub></sub></span><span>column </span><span>estimates, at fine </span><span>spatial</span><span> resolution </span><span>(7 km x 3.5 km at nadir) and </span><span>associated averaging kernels</span><span>,</span><span> during this eruptive period made it also an excellent case study. </span><span>It </span><span>allow</span><span>s</span><span> us to follow the evolution of SO<sub>2</sub> in the volcanic plume over several days.</span></p><p><span>Using the CNRM MOCAGE chemistry-transport model (CTM), we aim to quantify the impact of this volcanic eruption on atmospheric composition, sulfur deposition and air quality at the regional scale. The comparison of the model with the TROPOMI observation data allows us to assess the ability of the model to properly represent the plume. In spite of a particular meteorological situation, leading to a complex plume transport, MOCAGE shows a good agreement with TROPOMI observations. Thus, from the MOCAGE simulation, we can evaluate the impact of the eruption on the regional concentrations of SO<sub>2</sub> and sulfate aerosols, but also analyse the quantities of dry and wet deposition, and compare it to surface measurement stations.</span></p>



2020 ◽  
Author(s):  
Clarissa Kroll ◽  
Alon Azulay ◽  
Hauke Schmidt ◽  
Claudia Timmreck

<p><span>Stratospheric water vapor (SWV) is important not only for stratospheric ozone chemistry but also due to its influence on the atmospheric radiation budget.</span></p><p><span>After volcanic eruptions, SWV is known to increase due to two different mechanisms: First, water within the volcanic plume is directly injected into the stratosphere during the eruption itself. Second, the volcanic aerosols lead to a warming of the lower stratosphere including the tropopause layer. The increased temperature of the cold point allows an increased water vapor transit from the troposphere to the stratosphere. Not much is known about this process as it is obscured by internal variability and observations are scare.</span></p><p><span>To better understand the increased SWV entry via the indirect pathway after volcanic eruptions we employ a suite of large volcanically perturbed ensemble simulations of the MPI-ESM1.2-LR for five different eruptions strengths (2.5 Mt, 5 Mt, 10 Mt, 20 Mt and 40 Mt sulfur). Each ensemble consists of 100 realizations for a time period of 3 years.</span></p><p><span>Our work mainly focuses on the tropical tropopause layer (TTL) quantifying changes in relevant parameters such as the atmospheric temperature profile and the consequent increase in SWV. A maximum increase of up to 4 ppmm in the first two years after the eruption is found in the case of the 40 Mt eruption. Furthermore the large ensemble size additionally allows for an analysis of the statistical significance and influence of variability, showing that SWV increases can already be detected for the 2.5 Mt eruption in the ensemble mean, for single ensemble members the internal variability dominates the SWV entry up to an eruption strength of 10 Mt to 20 Mt depending on the season and time after the eruption. The study is complemented by investigations using the 1D radiative convective equilibrium model konrad to understand the radiative effects of the SWV increase.</span></p>



2013 ◽  
Vol 13 (19) ◽  
pp. 9713-9729 ◽  
Author(s):  
A. Stenke ◽  
C. R. Hoyle ◽  
B. Luo ◽  
E. Rozanov ◽  
J. Gröbner ◽  
...  

Abstract. Previous studies have highlighted the severity of detrimental effects for life on earth after an assumed regionally limited nuclear war. These effects are caused by climatic, chemical and radiative changes persisting for up to one decade. However, so far only a very limited number of climate model simulations have been performed, giving rise to the question how realistic previous computations have been. This study uses the coupled chemistry climate model (CCM) SOCOL, which belongs to a different family of CCMs than previously used, to investigate the consequences of such a hypothetical nuclear conflict. In accordance with previous studies, the present work assumes a scenario of a nuclear conflict between India and Pakistan, each applying 50 warheads with an individual blasting power of 15 kt ("Hiroshima size") against the major population centers, resulting in the emission of tiny soot particles, which are generated in the firestorms expected in the aftermath of the detonations. Substantial uncertainties related to the calculation of likely soot emissions, particularly concerning assumptions of target fuel loading and targeting of weapons, have been addressed by simulating several scenarios, with soot emissions ranging from 1 to 12 Tg. Their high absorptivity with respect to solar radiation leads to a rapid self-lofting of the soot particles into the strato- and mesosphere within a few days after emission, where they remain for several years. Consequently, the model suggests earth's surface temperatures to drop by several degrees Celsius due to the shielding of solar irradiance by the soot, indicating a major global cooling. In addition, there is a substantial reduction of precipitation lasting 5 to 10 yr after the conflict, depending on the magnitude of the initial soot release. Extreme cold spells associated with an increase in sea ice formation are found during Northern Hemisphere winter, which expose the continental land masses of North America and Eurasia to a cooling of several degrees. In the stratosphere, the strong heating leads to an acceleration of catalytic ozone loss and, consequently, to enhancements of UV radiation at the ground. In contrast to surface temperature and precipitation changes, which show a linear dependence to the soot burden, there is a saturation effect with respect to stratospheric ozone chemistry. Soot emissions of 5 Tg lead to an ozone column reduction of almost 50% in northern high latitudes, while emitting 12 Tg only increases ozone loss by a further 10%. In summary, this study, though using a different chemistry climate model, corroborates the previous investigations with respect to the atmospheric impacts. In addition to these persistent effects, the present study draws attention to episodically cold phases, which would likely add to the severity of human harm worldwide. The best insurance against such a catastrophic development would be the delegitimization of nuclear weapons.



2016 ◽  
Vol 12 (6) ◽  
pp. 1361-1374 ◽  
Author(s):  
Rudolf Brázdil ◽  
Ladislava Řezníčková ◽  
Hubert Valášek ◽  
Lukáš Dolák ◽  
Oldřich Kotyza

Abstract. The eruption of Mount Tambora in Indonesia in 1815 was one of the most powerful of its kind in recorded history. This contribution addresses climatic responses to it, the post-eruption weather, and its impacts on human life in the Czech Lands. The climatic effects are evaluated in terms of air temperature and precipitation on the basis of long-term homogenised series from the Prague-Klementinum and Brno meteorological stations, and mean Czech series in the short term (1810–1820) and long term (1800–2010). This analysis is complemented by other climatic and environmental data derived from rich documentary evidence. Czech documentary sources make no direct mention of the Tambora eruption, neither do they relate any particular weather phenomena to it, but they record an extremely wet summer for 1815 and an extremely cold summer for 1816 (the "Year Without a Summer") that contributed to bad grain harvests and widespread grain price increases in 1817. Possible reasons for the cold summers in the first decade of the 19th century reflected in the contemporary press included comets, sunspot activity, long-term cooling and finally – as late as 1817 – earthquakes with volcanic eruptions.



2013 ◽  
Vol 13 (5) ◽  
pp. 12089-12134
Author(s):  
A. Stenke ◽  
C. R. Hoyle ◽  
B. Luo ◽  
E. Rozanov ◽  
J. Gröbner ◽  
...  

Abstract. Previous studies have highlighted the severity of detrimental effects for life on Earth after an assumed regionally limited nuclear war. These effects are caused by climatic, chemical and radiative changes persisting for up to one decade. However, so far only a very limited number of climate model simulations have been performed, giving rise to the question how realistic previous computations have been. This study uses the coupled chemistry climate model (CCM) SOCOL, which belongs to a different family of CCMs than previously used, to investigate the consequences of such a hypothetical nuclear conflict. In accordance with previous studies, the present work assumes a scenario of a nuclear conflict between India and Pakistan, each applying 50 warheads with an individual blasting power of 15 kt ("Hiroshima size") against the major population centers, resulting in the emission of tiny soot particles, which are generated in the firestorms expected in the aftermath of the detonations. Substantial uncertainties related to the calculation of likely soot emissions, particularly concerning assumptions of target fuel loading and targeting of weapons, have been addressed by simulating several scenarios, with soot emissions ranging from 1 to 12 Tg. Their high absorptivity with respect to solar radiation leads to a tremendous self-lofting of the soot particles into the strato- and mesosphere, where they remain for several years. Consequently, the model suggests Earth's surface temperatures to drop by several degrees Celsius due to the shielding of solar irradiance by the soot, indicating a major global cooling. In addition, there is a substantial reduction of precipitation lasting 5 to 10 yr after the conflict, depending on the magnitude of the initial soot release. Extreme cold spells associated with massive sea ice formation are found during Northern Hemisphere winter, which expose the continental land masses of Northern America and Eurasia to chilling coldness. In the stratosphere, the strong heating leads to an acceleration of catalytic ozone loss and, consequently, to enhancements of UV radiation at the ground. In contrast to surface temperature and precipitation changes, which show a linear dependence to the soot burden, there is a saturation effect with respect to stratospheric ozone chemistry. Soot emissions of 5 Tg lead to an ozone column reduction of almost 50% in northern high latitudes, while emitting 12 Tg only increases ozone loss by a further 10%. In summary, this study, though using a different chemistry climate model, corroborates the previous investigations with respect to the atmospheric impacts. In addition to these persistent effects, the present study draws attention to episodically cold phases, which would likely add to the severity of human harm worldwide. The best insurance against such a catastrophic development would be the delegitimization of nuclear weapons.



2016 ◽  
Author(s):  
Rudolf Brázdil ◽  
Ladislava Řezníčková ◽  
Hubert Valášek ◽  
Lukáš Dolák ◽  
Oldřich Kotyza

Abstract. The eruption of Mount Tambora in Indonesia in 1815 was one of the most powerful of its kind in recorded history. This contribution addresses climatic responses to it, the post-eruption weather, and its impacts on human life in the Czech Lands. The climatic effects are evaluated in terms of air temperature and precipitation on the basis of long-term homogenised series from the Prague-Klementinum and Brno meteorological stations, and mean Czech series in the short term (1810–1820) and long-term (1800–2010). This analysis is complemented by other climatic and environmental data derived from rich documentary evidence. Czech documentary sources make no direct mention of the Tambora eruption, neither do they relate any particular weather phenomena to it, but they record extremely cold and wet summers for 1815 and 1816 (the "Year Without a Summer") that contributed to bad grain harvests and widespread grain price increases in 1817. Possible reasons for the cold summers in the first decade of the 19th century cited in the contemporary press included comets, sunspot activity, long-term cooling and finally – as late as 1817 – earthquakes with volcanic eruptions. Here, the Tambora event is compared with the 1783 eruption of Lakagígar in Iceland, with its clearly-pronounced post-volcanic effects on the weather in central Europe (dry fog, heavy thunderstorms, optical phenomena) and the occurrence of significant cold temperature anomalies in winter 1783/84, spring 1784 and the summer and autumn of 1785. These appeared clearly in central European series, Prague-Klementinum included. Comparison of the two eruptions shows that the effects of the Lakagígar eruption in the Czech Lands were climatologically stronger those of the Tambora eruption, while the opposite held for societal responses.



Author(s):  
Roy Livermore

The Earth’s climate changes naturally on all timescales. At the short end of the spectrum—hours or days—it is affected by sudden events such as volcanic eruptions, which raise the atmospheric temperature directly, and also indirectly, by the addition of greenhouse gases such as water vapour and carbon dioxide. Over years, centuries, and millennia, climate is influenced by changes in ocean currents that, ultimately, are controlled by the geography of ocean basins. On scales of thousands to hundreds of thousands of years, the Earth’s orbit around the Sun is the crucial influence, producing glaciations and interglacials, such as the one in which we live. Longer still, tectonic forces operate over millions of years to produce mountain ranges like the Himalayas and continental rifts such as that in East Africa, which profoundly affect atmospheric circulation, creating deserts and monsoons. Over tens to hundreds of millions of years, plate movements gradually rearrange the continents, creating new oceans and destroying old ones, making and breaking land and sea connections, assembling and disassembling supercontinents, resulting in fundamental changes in heat transport by ocean currents. Finally, over the very long term—billions of years—climate reflects slow changes in solar luminosity as the planet heads towards a fiery Armageddon. All but two of these controls are direct or indirect consequences of plate tectonics.



2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Suvarna Fadnavis ◽  
Rolf Müller ◽  
Tanusri Chakraborty ◽  
T. P. Sabin ◽  
Anton Laakso ◽  
...  

AbstractThe Indian summer monsoon rainfall (ISMR) is vital for the livelihood of millions of people in the Indian region; droughts caused by monsoon failures often resulted in famines. Large volcanic eruptions have been linked with reductions in ISMR, but the responsible mechanisms remain unclear. Here, using 145-year (1871–2016) records of volcanic eruptions and ISMR, we show that ISMR deficits prevail for two years after moderate and large (VEI > 3) tropical volcanic eruptions; this is not the case for extra-tropical eruptions. Moreover, tropical volcanic eruptions strengthen El Niño and weaken La Niña conditions, further enhancing Indian droughts. Using climate-model simulations of the 2011 Nabro volcanic eruption, we show that eruption induced an El Niño like warming in the central Pacific for two consecutive years due to Kelvin wave dissipation triggered by the eruption. This El Niño like warming in the central Pacific led to a precipitation reduction in the Indian region. In addition, solar dimming caused by the volcanic plume in 2011 reduced Indian rainfall.



2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Sergey Osipov ◽  
Georgiy Stenchikov ◽  
Kostas Tsigaridis ◽  
Allegra N. LeGrande ◽  
Susanne E. Bauer ◽  
...  

AbstractSupervolcano eruptions have occurred throughout Earth’s history and have major environmental impacts. These impacts are mostly associated with the attenuation of visible sunlight by stratospheric sulfate aerosols, which causes cooling and deceleration of the water cycle. Supereruptions have been assumed to cause so-called volcanic winters that act as primary evolutionary factors through ecosystem disruption and famine, however, winter conditions alone may not be sufficient to cause such disruption. Here we use Earth system model simulations to show that stratospheric sulfur emissions from the Toba supereruption 74,000 years ago caused severe stratospheric ozone loss through a radiation attenuation mechanism that only moderately depends on the emission magnitude. The Toba plume strongly inhibited oxygen photolysis, suppressing ozone formation in the tropics, where exceptionally depleted ozone conditions persisted for over a year. This effect, when combined with volcanic winter in the extra-tropics, can account for the impacts of supereruptions on ecosystems and humanity.



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