Originally published on
by at Arctic News
by Andrew Glikson
Despite of deceptively-claimed mitigation of greenhouse gas (GHG) emissions in parts of the world, ongoing burning of domestic and exported fossil fuels world-wide continues to change the composition of the atmosphere, enriching it in greenhouse gases by yet another ~2 ppm CO₂ (2022: 418.95 ppm; CH₄: 1915 ppb; N₂0: 337 ppb), reaching levels commensurate with those of the Miocene (23.03 to 5.333 Ma) at rise rates exceeding any in the geological record of the last 66 million years (Glikson, 2020) (Figure 1).
|Figure 1. Global 1880-2021 annual average temperatures (adapted by UCAR from ClimateCentral).|
Since 1880 mean global temperatures rose at a rate of 0.08°C per decade, from 1981 by 0.18°C per decade and more when emitted aerosols are accounted for (Hansen et al., in Berwyn, 2022). According to Will Steffen, Australia’s leading climate scientist “there was already a chance we have triggered a global tipping cascade that would take us to a less habitable Hothouse Earth climate, regardless of whether we reduced emissions” (Figure 2).
|Figure 2. Global mean temperature profile since 200 AD projected to beyond 2000 AD (Will Steffen)|
Over a brief span of less than two centuries (Figure 1) anthropogenic reversal of the carbon cycle induced the emission of some 1.5 10¹² tonnes of CO₂ and an increased release of 150% more CH₄ from the crust, accumulated in sediments for hundreds of million years through photosynthesis and calcification, as well as from permafrost and oceans. Permeation of the atmosphere and the hydrosphere with the toxic residues of ancient plants and organisms, poisoning the biosphere, is leading to the Sixth mass extinction of species in the history of nature.
Following failed attempts to deny climate science, vested business and political interests are proceeding, with the support of many governments, to mine coal, sink oil wells and frack hydrocarbon gas, regardless of the consequences in term of global heating, sea level rise, inundation of islands and coastal zones, collapse of the permafrost, heat waves, floods, ocean acidification, migration of climate zones and dissemination of plastic particles, rendering the future of much of the biosphere uninhabitable.
|Figure 3. Europe: Maximum extreme temperatures, July 17-23, 2002.|
The progression of global warming is unlikely to be linear as the flow of cold ice melt water from Greenland and Antarctica glaciers would cool parts of the ocean and in part the continents (Figure 4), leading toward a stadial-type phenomenon, the classic case of which is symbolized by the Younger dryas cool period 12,900 to 11,700 years ago.
|Figure 4. Projected transient stadial cooling events (Hansen et al., 2016)|
There was a time when leaders fell on their sword when defeated in battle or lose their core beliefs, nowadays most not even resign their privileged positions to resist the existential danger posed to advanced life, including human civilization, preoccupied as nations are with preparations for nuclear wars.
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
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