“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 even reverse, global warming and its consequences for the habitability of planet Earth remains an open question, for which neither climate science nor the media dominated by politicians and economists, oblivious to the basic laws of physics, have a definitive answer. However, it is likely that over the next centuries or longer the flow of cold water from the melting Greenland and Antarctica ice sheets will lead do a transient slow down the rate of warming before the large ice sheets are exhausted..
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A projection by NOAA states: “While we cannot stop global warming overnight, we can slow the rate and limit the amount of global warming by reducing human emissions of heat-trapping gases and soot (“black carbon”). However, this projection does not take the amplifying feedback of warming, i.e. from warming oceans, desiccating and burning vegetation and migrating climate zones, as well as the timefactor into account.
Having ignored climate science, dismissed climate scientists and repeatedly confected untruths, while global heating accelerates with deleterious consequences (Figure 1), 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) indicate mean global temperature is currently accelerating by the middle of the decade toward 2.0oC above pre-industrial temperature (Figure 1). The Arctic has been 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 than the rest of the world.
Figure. 1. Global temperature relative to 1880-1920 based on the GISS (Goddard Institute of Space Studies) analysis (Hansen et al., 2023).
As the polar regions warm the tropical climate zones expand and the mid-latitudes, where the most fertile soils and the bulk of population live, 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 next decades.
- Negative impacts of heat stress are expected to nonlinearly increase in large parts of southern and southeastern Europe.
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 (coloured areas), while grey-colour denotes the areas where the agro-climate zones have not changed.
A projection by NOAA states: “While we cannot stop global warming overnight, we can slow the rate and limit the amount of global warming by reducing human emissions of heat-trapping gases and soot (“black carbon”). This projection takes neither the amplifying feedback, i.e. from warming of the oceans, melting ice sheets, melting of the permafrost, migrating climate zones, nor the timefactor into account.
Factors rendering a potential reversal of global warming in the short term unlikely include:
A) 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.
B) Where scientific breakthroughs would allow effective climate mitigation, for example global cooling by CO2 drawdown, the question is whether Homo sapiens ─ recorded throughout history as an invasive blood-stained tribal species ─ would be able to avoid destroying its home planet?
The apparent absence of radio signals from technological civilizations in the Milky Way may suggest that advanced civilizations tend to undergo self-destruction, consistent with local observations, referred to as the “Fermi Paradox”.
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” (Hansen et al., 2016) (Figure 3).
Here the flow of ice-melt water results in formation of large cold pools in the north Atlantic Ocean and the Southern Ocean (Figure 3), related to an overall decline in mean global temperatures to -0.33oC by 2096 (Figure 3B) due to the flow of ice melt water from Greenland and Antarctica.
The collision between the cold air and water fronts and the tropical warm air mass would lead to intense storms over large parts of Earth. Such transient cooling may allow Homo “Sapiens” a respite from global warming before his home becomes an uninhabitable planet.
Andrew Glikson, Earth and climate scientist
