by Andrew Glikson
“Without major action to reduce emissions, global temperature is on track to rise
by 2.5°C to 4.5°C by 2100” (NASA 2023)
“We Will Not Sign Our Own Death Warrant” (a delegate at COP28)
Whether anything can be done by humans to arrest or reverse global warming and its consequences for the habitability of planet Earth remains an open question, for which neither climate science nor the ignorant hordes of politicians and economists, oblivious to the basic laws of physics, have the answer. However, it is likely that over the next centuries or longer the flow of cold water from the melting of the Greenland and Antarctica ice sheets will lead to a transient slowdown of the rate of warming before the large ice sheets are exhausted.
Having ignored climate science, dismissed climate scientists and repeatedly confected untruths, while global heating accelerates with deleterious consequences, Homo “sapiens” finds itself on track toward carbon poisoning of the atmosphere, the lungs of the inhabitable Earth, acidification of the hydrosphere and coating of the land with carbon and plastics.
In a new paper, a group of leading climate scientists (Hansen et al., 2023) indicates mean global temperature is currently accelerating toward 2.0°C above pre-industrial temperature by the middle of the decade (Figure 1). The Arctic is warming nearly four times faster than the rest of the world over the last 43 years, on average around 3℃ warmer than it was in 1980. Over the past 30 years Antarctica has been one of the fastest-changing places on Earth, warming more than 3 times faster than the rest of the world.
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| [ Figure. 1. Global temperature relative to 1880-1920 based on the GISS (Goddard Institute of Space Studies) analysis - by James Hansen et al., 2023. ] |
As the polar regions warm, the tropical climate zones expand and the mid-latitudes, where the most fertile soils are and where the bulk of the population lives, are contracting.
Thus (Figure 2.):
- Agro-climate zones in eastern Europe experienced a northward migration velocity of 100 km per 10 years over the past 40 years.
- Northward migration of climate zones in Europe may be up to two times faster in the next decades.
- Negative impacts of heat stress are expected to non-linearly increase in large parts of southern and southeastern Europe.
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| [ Figure 2. (a) Agro-climate zonation of Europe based on growing season length (GSL) and active temperature sum (ATS) for the period between 1975 and 1995.The identified agro-climate zones are named as follows (going from north to south): boreal north (BON), boreal south (BOS), nemoral (NEM), continental (CON), Pannonian (PAN), northern maritime (NMA), southern maritime (SMA) and Mediterranean (MED). (b) The migration of agro-climate zones between the 1975–1995 and 1996–2016 periods. For better distinction, only the areas affected by migration of agro-climate zones are displayed (colored areas), while gray color denotes the areas where the agro-climate zones have not changed - Ceglar et al. 2019. ] |
Factors rendering a potential reversal of global warming in the short term unlikely include:
- The rise of mean global heating above a level of ~1.5oC and much higher at the poles above pre-industrial temperatures, polar-ward migration of climate zones, melting of the Greenland and Antarctic ice sheets, intensification of extreme weather events, requiring major cooling of the Earth, which is unlikely within the time frame of a tribal-conflicted civilization.
- Where scientific breakthroughs would allow effective climate mitigation, for example global cooling by CO₂ drawdown, it is questionable whether Homo sapiens ─ recorded by history as an invasive blood-stained tribal species ─ would be able to avoid destroying its home planet.
A factor rarely taken into account emerges from the key paper “Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modelling, and modern observations that 2°C global warming could be dangerous”, by Hansen et al. (1996) (Figure 3.).
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Here the flow of cold ice-melt water results in formation of large cold pools in the Atlantic Ocean and Southern Ocean (Figure 3), related to an overall decline in mean global temperatures to -0.33°C by 2096 (Figure 4.) due to the flow of cold ice-melt water from Greenland and Antarctica.
While the collision between the cold air and water fronts and the tropical war air mass would lead to intense storms over large tracts of Earth, such transient cooling may allow Home "sapiens" a respite from global warming before its home becomes an uninhabitable planet.
While the collision between the cold air and water fronts and the tropical war air mass would lead to intense storms over large tracts of Earth, such transient cooling may allow Home "sapiens" a respite from global warming before its home becomes an uninhabitable planet.
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| [ Figure 4. Surface air temperature (◦C) relative to 1880–1920 in (a) 2065, (b) 2080, and (c) 2096. Top row is IPCC scenario A1B. Ice melt with 10-year doubling is added in other scenarios - James Hansen et al. 2016. ] |
A/Prof. Andrew Y Glikson
Earth and Paleo-climate scientist
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| Andrew Glikson |
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
