Showing posts with label heatwaves. Show all posts
Showing posts with label heatwaves. Show all posts

Thursday, July 20, 2023

Planetary Inferno: Nero fiddles while Rome burns

by Andrew Glikson

The fast rise in global warming manifested by current extreme weather events betrays a dangerous underestimation of the Earth’s liveable climate, while governments ignore climate science, claim to set limits on domestic emissions, but allow major export of fossil fuels and emissions worldwide on a scale threatening life on Earth. With current policies, there appear to exist few limits on global carbon emissions, as reported by Rogner (1997): “The global fossil resource base is abundant and is estimated at approximately 5000 Gt (billion tons). Compared to current global primary energy use of some 10 Gt per year, this amount is certainly sufficient to fuel the world economy through the twenty-first century”. According to these estimates, future production of coal, oil and gas render a mass extinction of advanced species more than likely.

A significant fraction of carbon gases released from combustion of fossil fuels on timescales of a few centuries remains in the atmosphere as well as leads to acidification of the oceans at a rate faster than its removal by weathering processes and deposition of carbonates. Common measures of the atmospheric lifetime of CO₂ disregard the long time tail of its dissipation, which underestimates the longevity of anthropogenic global warming. Models agree 20–35% of the CO₂ remains in the atmosphere after equilibration with the ocean (over 2–20 centuries). Neutralization by CaCO₃ draws the airborne fraction down further on timescales of 3 to 7 kyr.

With atmospheric CO₂ levels reaching 423 parts per million, according to James Hansen and colleagues humanity is facing a new Frontier, marked by intense heatwaves, more than vindicating warnings by climate scientists over the last 40 years or so. Within less than a century, the levels of CO₂ and temperatures have risen to levels of the Miocene (23.03–5.33 million years ago), with implications for sea level rise (Spratt, 2023). Hominids, living during glacial to inter-glacial periods, rarely had to endure mean temperatures higher than 50°C, which are increasingly common at present. Governments, busy subsidizing new coal mines and oil and gas wells and arming to the teeth for nuclear war, appear to be oblivious to the lessons of the last great world wars.
Figure 1. Global temperature anomalies relative to 1880-1920. Accelerated warming rate are 0.36°C and 0.27°C per decade. Super-El-Niño, projected for 2023, occurs at +0.8 to +1.2 temperature. (Hansen et al., 2023, The climate dice).

No longer does climate change represent a future scenario debated by scientists or deniers, but it constitutes an accelerating reality (Figures 1 and 2) related to the latitudinal shift of climate zones, including expansion of the tropics into temperate regions, Europe and north America. The weakening of the circum-polar jet stream allows heat cells to penetrate polar latitudes and cold fronts to enter high latitude zones. The consequences are represented by accumulation of ice melt water off Greenland and parts of the circum-Antarctic ocean (Figure 2). Increased evaporation over land masses results in draughts, while evaporation from warming oceans gives rise to major floods over large continental regions.
Figure 2. June 2023 global surface temperature anomaly (°C) relative to 1951-1980 June mean. Note the major high latitude temperature anomalies reaching 3 – 4°C above the 1951-1980 June mean. (Hansen et al., 2023, The climate dice).
According to Sharpless et al. (2023)“Heatwaves have been going through some extraordinary changes in recent history. Since midway through the 20th century, their intensity, frequency and duration have increased across the globe and these changes are happening faster and faster. Research indicates that this is simply not possible without human influence on the climate. A child born today could see an extra 30 to 50 heatwave days every year by the time they are 80, up from roughly four to 10 days today. Southern states of Australia, such as Victoria and South Australia, which already experience the country’s hottest heatwaves, could see hot days become hotter by up to 4 degrees Celsius. There may be more heatwaves in the near future with the Bureau of Meteorology forecasting drier and warmer conditions across much of Australia for July to September this year. These conditions, which often occur during an El Niño, can lead to reduced rainfall, higher temperatures and a greater risk of bushfires. Across Europe, heatwaves may become hotter by up to 10 degrees Celsius and some heatwaves will last up to two months by the end of this century. In just the next 20 years, the USA will experience three to five more heatwaves every decade compared to the second half of the 20th century. Heatwaves are closely linked to droughts. Generally, a large amount of energy from the Sun goes into drying out moisture in the landscape. But as the amount of moisture available for evaporation declines during a drought, more energy is available for heating the air and the temperature rises. This can become a vicious cycle of increasing evaporation and desiccation of the land surface”.

There was a time when kings and generals would fall on their sword when they were defeated, or when their faith in their gods collapsed. Nowadays so-called leaders, assuming opportunistic positions, betray the defence of their own people and of nature, protecting or advancing their own careers. The voices of climate scientists have become subdued, ignored or non-existent. There may not be too many historians to document the 20-21ˢᵗ centuries crimes against humanity and against nature.

Andrew Glikson
A/Prof. Andrew Y Glikson
Earth and Paleo-climate scientist

Books:
The Asteroid Impact Connection of Planetary Evolution
https://www.springer.com/gp/book/9789400763272
The Archaean: Geological and Geochemical Windows into the Early Earth
https://www.springer.com/gp/book/9783319079073
The Plutocene: Blueprints for a Post-Anthropocene Greenhouse Earth
https://www.springer.com/gp/book/9783319572369
The Event Horizon: Homo Prometheus and the Climate Catastrophe
https://www.springer.com/gp/book/9783030547332
Climate, Fire and Human Evolution: The Deep Time Dimensions of the Anthropocene
https://www.springer.com/gp/book/9783319225111
Evolution of the Atmosphere, Fire and the Anthropocene Climate Event Horizon
https://www.springer.com/gp/book/9789400773318
From Stars to Brains: Milestones in the Planetary Evolution of Life and Intelligence
https://www.springer.com/us/book/9783030106027
Asteroids Impacts, Crustal Evolution and Related Mineral Systems with Special Reference to Australia
https://www.springer.com/us/book/9783319745442
The Fatal Species: From Warlike Primates to Planetary Mass Extinction
https://www.springer.com/gp/book/9783030754679
The Trials of Gaia. Milestones in the evolution of Earth with reference to the Antropocene
https://www.amazon.com.au/Trials-Gaia-Milestones-Evolution-Anthropocene/dp/3031237080





Tuesday, December 7, 2021

Planetwide Ecocide - The Crime Against Life on Earth

by Andrew Glikson



“We are simply talking about the very life support system of this planet.”
Hans Joachim Schellnhuber, Germany’s former chief climate scientist (2009)

“Burning all fossil fuels would create a very different planet than the one that humanity knows. The palaeoclimate record and ongoing climate change make it clear that the climate system would be pushed beyond tipping points, setting in motion irreversible changes, including ice sheet disintegration with a continually adjusting shoreline, extermination of a substantial fraction of species on the planet, and increasingly devastating regional climate extremes” and “this equates 400,000 Hiroshima atomic bombs per day 365 days per year” . James Hansen et al. 2012 and James Hansen 2012.

Figure 1. The change in state of the planetary climate since the onset of the industrial age in the 18ᵗʰ century.

During its last 600 million years-long history planet Earth suffered at least five major mass extinctions, defining the ends of several eras of the Ordovician, Devonian, Permian, Jurassic and Cretaceous, triggered by extra-terrestrial impacts, massive volcanic eruptions, methane release or ocean anoxia. Each of these events included the release of greenhouse gases, inducing changes in atmospheric composition and temperature (Figures 1, 2 and 3). Excepting the role of methanogenic bacteria in releasing methane, the anthropogenic mass extinction constitutes an exception: For the first time in its history the atmosphere, the oceans and the biosphere are disrupted by a living organism, namely the activity of a carbon-emitting biped mammal species.

Fig 2. Temperature trends for the past 65 Ma and potential geo-historical analogs for future climates (Burke et al. (2018)

In the wake of the Pliocene (2.6-5.3 Ma-ago), with temperatures in the range of (+2°C to 3°C above pre-industrial levels) and sea levels (+25 meters) higher than at present, the development of glacial-interglacial conditions saw the appearance of Homo erectus and then Homo sapiens. Between about 10,000 and 7,000 years ago, the stabilization of the climate in the Holocene saw Neolithic agricultural civilization take hold. Anthropogenic processes during this period, denoted as the Anthropocoene (Steffen et al., 2007), led to deforestation and the demise of species, ever increasing carbon pollution of the atmosphere, temperature rise (Figures 1 and 2), acidification, radioactive contamination and a growing threat to the Earth’s life support systems.

Planetwide ecocide results from anthropogenic emission of greenhouse gases into the atmosphere, raising their combined forcing (CO₂ + CH₄ + N₂O, etc.) to levels over 500 ppm CO₂-equivalent, (Figure 3), almost doubling the pre-industrial CO₂ level of ~280 ppm, and corresponding to a rise of +3°C per doubling of CO₂ levels. The consequence of extraction and combustion of the buried products of ancient biospheres, threatens to return Earth to conditions which preceded the emergence of large mammals on land.

Figure 3. Pre-1978 changes in the CO₂-equivalent abundance and AGGI (Annual Greenhouse Gas Index). NOAA Global Monitoring Laboratory

The sharp glacial-interglacial oscillations of the Pleistocene (2.6 million to 10,000 years ago), with rapid mean global temperature changes of up to 5°C over a few millennia and abrupt stadials cooling events over a few years (Steffensen et al., 2008), required humans to develop an extreme adaptability, in particular mastering fire, a faculty no other species, perhaps with the exception of fire birds. Proceeding to manipulate the electromagnetic spectrum, split the atom and travel to other planets, a cultural evolution overtaking biological evolution, the power of sapiens appears to have gone out of control.

Humans have developed an absurd capacity to simultaneously create and destroy, culminating with the destruction of environments that allowed them to flourish in the first place. Possessed by a conscious fear of death and a craving for god-like immortality, there is no murderous obscenity some were not willing to perform, including the transfer of every accessible carbon molecule to the atmosphere.

Based on direct observations and the basic laws of physics, the life support systems of the biosphere are threatened by the rise of greenhouse gases and temperature by an average of more than 1.14°C since 1880, currently tracking toward 2°C. These values take little account of the masking effects of the transient mitigating effects of sulphate aerosols in the range of −0.3 to −1.8 Wm⁻², pushing mean global temperature to >1.5°C. Following the current acceleration (Figure 3), mean temperature could reach 2°C by 2030, 3°C by the 2050s and 4°C by 2100, inducing heat waves and major fires.

Figure 4. Jet Stream, summer, 1988, NASA. Increased undulation of the Arctic boundary zone, allowing penetration of cold air masses southward and warm air masses northward;

Overall warming of large ocean regions, reaching ~700 meter deep levels, reduces the ocean’s ability to absorb CO₂ while much of the gas is trapped in the atmosphere. As ocean heat contents rise oxygen is depleted and methane and hydrogen sulphide poisonous for marine life are produced. Models projecting global warming as a linear trajectory, outlined by the IPCC, take limited account of amplifying feedbacks and transient stadial cooling effects from the flow of ice melt water into near-polar oceans. As the circum-Arctic jet stream undulates and weakens (Figure 4), polar-ward shifts of climate zones (Figure 5) allow penetration of warm air masses into the Arctic, manifested by heat waves and fires. Conversely, injection of cold air masses from the Arctic into mid-latitudes ensues in freezing fronts producing violent snow storms, the so-called “Beast from the East”.

Figure 5. The migration of the Sahara arid climate zone northward into southern Europe. Note the drying up of Spain, Italy, Greece and Turkey and the increased in precipitation in Northern Europe.

As stated by Baronsky et al. (2013) in the paper “Approaching a state shift in Earth's biosphere”: “Localized ecological systems are known to shift abruptly and irreversibly from one state to another when they are forced across critical thresholds. Here we review evidence that the global ecosystem as a whole can react in the same way and is approaching a planetary-scale critical transition as a result of human influence’’ and “Climates found at present on 10–48 % of the planet are projected to disappear within a century, and climates that contemporary organisms have never experienced are likely to cover 12–39 % of Earth. The mean global temperature by 2070 (or possibly a few decades earlier) will be higher than it has been since the human species evolved’’. Figure 6 outlines critical habitats and species involved in the transition.

Figure 6. Summary of major biodiversity-related environmental-change categories expressed as a percentage of human-driven change (in red) relative to baseline (blue); Corey J. A. Bradshaw; Paul R. Ehrlich; Andrew Beattie; et al. (13 January 2021). https://www.frontiersin.org/files/Articles/615419/fcosc-01-615419-HTML-r1/image_m/fcosc-01-615419-g001.jpg - “Underestimating the Challenges of Avoiding a Ghastly Future”, in Frontiers in Conservation Science, volume 1, 13 January 2021. Red indicates the percentage of the category that is damaged, lost, or otherwise affected, whereas blue indicates the percentage that is intact, remaining, or otherwise unaffected.

 
As $trillions are invested in future wars, who or what will defend life on Earth?



Andrew Glikson
A/Prof. Andrew Glikson

Earth and Paleo-climate scientist
School of Biological, Earth and Environmental Sciences
The University of New South Wales,
Kensington NSW 2052 Australia

Books:
The Asteroid Impact Connection of Planetary Evolution
https://www.springer.com/gp/book/9789400763272
The Archaean: Geological and Geochemical Windows into the Early Earth
https://www.springer.com/gp/book/9783319079073
Climate, Fire and Human Evolution: The Deep Time Dimensions of the Anthropocene
https://www.springer.com/gp/book/9783319225111
The Plutocene: Blueprints for a Post-Anthropocene Greenhouse Earth
https://www.springer.com/gp/book/9783319572369
Evolution of the Atmosphere, Fire and the Anthropocene Climate Event Horizon
https://www.springer.com/gp/book/9789400773318
From Stars to Brains: Milestones in the Planetary Evolution of Life and Intelligence
https://www.springer.com/us/book/9783030106027
Asteroids Impacts, Crustal Evolution and Related Mineral Systems with Special Reference to Australia
https://www.springer.com/us/book/9783319745442
The Event Horizon: Homo Prometheus and the Climate Catastrophe
https://www.springer.com/gp/book/9783030547332
The Fatal Species: From Warlike Primates to Planetary Mass Extinction
https://www.springer.com/gp/book/9783030754679

 

Friday, May 16, 2014

More extreme weather can be expected



The heaviest rains and floods in 120 years have hit Serbia and Bosnia this week, Reuters and Deutsche Welle report.

The animation below shows the Jet Stream's impact on the weather. Cold temperatures have descended from the Arctic to Serbia and Bosnia in Europe and all the way down to the Gulf of Mexico in North America, while Alaska, California, and America's East Coast are hit by warm temperatures. In California, 'unprecedented' wildfires and fierce winds lead to 'firenadoes', reports CNN.