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David Lentz's avatar

It’s very interesting if microplastics could collapse populations via hormone disruption

Amphibians have had massive populations damage as their life cycle so impacted by chemical disruption

Insect populations collapsed also

Humans next?

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Peace2051's avatar

The big unknown is how social cohesion across nations and the world will hold up while experiencing mass mortality due to malnutrition and opportunistic diseases. Ugo, your book Extinctions was so thoughtfully researched and presented, you would be the best person I know if to write a book on how societies contracted yet held together during the waves of Black Plague which killed 30 to 60% of the population. Are you looking for another project to write from a collapse perspective?

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Athanasius's avatar

Hypothetical scenario: Carboniferous 2.0

The abundance of CO2 open the path of hi efficiency routes of photosynthesis (today CO2 limited, is used to pump CO2 to boost plant growth) and an explosion of hyperactive photosensitizer life. Usually we didn't see it but overabundance of life is more dangerous than scarce, to human a jungle is more dangerous and difficult to survive compared to deserts and is the breeding ground of some of the most fearsome pestilences and pathogens ever seen: Black Death is traced to his origin in Asian jungles, Central Africa was source of quite a lot of interesting things, Ebola and Malaria as example and so on. Our infrastructure is quite vulnerable to plants as roots could easily fracture stones, so our building materials are almost trivial to infiltrate and bring down, they also contain phenomenal concentration of useful elements to plants as iron (used to promote plankton growth). Abundant food from plants could also be an interesting paradox, animals are more adapted to use differentiated sources of plants as foods, but humans are depending on domesticated ones so a vegetal kingdom in overdrive mode probably will push aside human crops favoring the kingdom most efficient in fast consumption and metallization of vegetables: insects!

Human life in Carboniferous 2.0 will be harsh, reversion to hunter gathering could be the norm in a lot of places, colder, more inhospitable places to plant life could be the breeding ground to a new kind of civilization with an emphasis on a "fight with nature" subject to waves of pestilences and swarming insects. In some centuries we could imagine this new civilizations to venture in the vestiges of our civilization, admiring the last vestiges of crumbled edifices as we today admire the remaining of Khmer Empire with a twist: old empires built of stone that is quite resistant so we find their monuments even under a jungle and their documents literally written in stone, today we build almost universally with covetous material and refined iron that could be quickly reduced to almost nothing so our civilization will be a "lost one"!

Science fiction or fantasy tale but a possible one, we must remember that humans are a LOSING specie in terms of natural evolution, we are not and could not adapt to our environment and MUST modify it so we could be winner. This is depending on a lot of co factors and could be overwhelmed in more than one way, we are used to imagining a "desert Apocalypse" (Mad Max stile) but there are a lot of possible other Apocalypses waiting, Nature have a lot of fantasy and practice in mass extinction (oxygen Apocalypse was a peculiarly twisted one).

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Ugo Bardi's avatar

Minor problem, Athanasius. During the Carboniferous, the CO2 concentration was lower than it is now.

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Athanasius's avatar

I thought that was more than double during first period, then we got a sharp increase in O2 and corresponding decrease in CO2, as reference you could check this:

https://www.marist.edu/documents/d/guest/23f-paleoclimatology-lecture-5-10-3-2023-

Obviously, I'm open to correction but to me seemed like that because our coal is from Carboniferous it is logical that burning all coal we could only restore what was fixed during that period.

My rambling on the insects plague is lined to this period of gigantic spiders, dragonfly big as birds and so on, all wrapped in a jungle like environment keep running by excessive water cycle fueled by a temperature hotter than our by 10-20°C. Is quite funny to imagine human living in that environment used as we are to a quite tamed life on our planet.

If the documents on the arguments are right, End Permian concentration of CO2 are in the range 3,000-30,000 PPM during the corresponding mass extinction.

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