From a Miocene-like CO2 level of ~420 ppm to irreversible climate change
As terrestrial adversaries keep pushing the Earth and its inhabitants to within seconds of a nuclear catastrophe, looming through heat waves, extreme fires and flood events is the huge calamity of irreversible global warming.
Carbon dioxide (CO₂) reached levels well above 420 parts per million (ppm) at Mauna Lao, Hawaii, on February 13 and 14, 2022, as illustrated by the image, from an earlier post.
Can the current climate trend be arrested, or even reversed?
The current global greenhouse gas trend is leading to one of the largest mass extinctions of species in the geological record, one of the victims being human civilization. The current focus on emission reduction overlooks a major factor, namely the amplifying feedbacks from land and oceans (Steffen et al., 2018). There is a desperate need, in addition to emission reduction, for urgent large-scale sequestration of atmospheric greenhouse gases, and for further action to combat the temperature rise.
- an increase in evaporation, raising atmospheric water vapor levels, which enhances the greenhouse gas effect;
- a decline in the polar albedo (reflection) due to large-scale lateral and vertical melting of ice;
- release of methane from degrading permafrost and from polar sediments;
- reduced CO₂ intake by warming oceans. Currently the oceans absorb between 35-42% of all CO₂ and around 90% of the excess heat;
- warming, desiccation, deforestation and fires over land areas.
Numerous species have been unable to survive the accelerated global heating following the K-T impact event, nor are many species likely to survive the even higher rate of the of the Anthropocene catastrophe. A connection between climate change and human wars is evident from the accelerated global warming in the wake of the industrial-scale world wars I and II and subsequent industrial developments. It is possible that climate change could have been arrested in the 1960s had global efforts been directed at the time for abrupt cuts in emissions, transformation of agricultural and land clearing practices, and effort at CO₂ drawdown/sequestration. By the onset of the 21st century however, such efforts have hardly been undertaken and could yet turn out to be too late. The repetitions of humanity’s old warlike habits, investing resources in industries of death, genocidal wars associated with intensive carbon emissions, forecast in “The Fate of the Earth”, yield little promise for a change of direction.