We be Mega-3T; we are entering a Mega-4T.

[pbrower2a]

I see us approaching the end of a Crisis Era because of the timing. It is possible that expanded lifespans could extend a Saeculum, perhaps by lengthening eras within a Saeculum and lengthening the cohort of a generation perhaps from 18 to 25 years.That might not sound like much, but four generations would be separated in their last stages and first stages, respectively, by a century instead of about 72 years. This time we largely divided the generations by cultural influences. Pop music might exemplify the cultural distinction, with the GI generation going for Big Band, the Silent starting out "me too", only to drift into something more whimsical, then a splintered variety of Boomer expressions in music (including country and rhythm-and-blues and even some relatively cerebral and often folk-colored rock), then X pure hedonism with no intended message... So does culture define generations through attitudes or does the historical crucible fix a generation?

I think we just got a definition between the Millennial generation and what comes later. COVID-19 did not disrupt the youth rituals of coming of age for Millennial adults, but they certainly messed up many of them for the next generation from confirmations to first days in kindergarten to bar mitzvahs and quinceaneras, and graduation from high school and college. The Millennial generation could take these for granted; the next generation may not. This year something so predictable as sporting events end drastically or become travesties. Many seasonal celebrations and county fairs have been cancelled.

Now for the real megacrisis: just consider the effects of global warming that makes parts of the world now barely tolerable due to heat and humidity unlivable. Cities in this zone are in hot deserts and rainforest climates alike, including Khartoum, Mecca, Aden, Riyadh, Kuwait, Karachi, Mumbai, Madras, Rangoon, Bangkok, and Jakarta. People are in deep trouble when wet-bulb temperatures reach 35 C ((5 F) because they cannot cool by sweating. Then of course much of the world's prime farmland will be inundated, so just see what that does to food security. So populous a country of Bangladesh, which is now mostly peasant farmers, could be drowned. Where do the people go?

OK, climate bands will shift pole-ward -- but soils will not adapt quickly enough to climatic change to have fertile lands in Siberia and northern Canada.

St up Trump-like ideology as the norm with its contempt for science when such runs afoul of the profiteering ethos, and we will have a Crisis that could make the Crisis of 1940 (which featured the Holocaust!) look tame by contrast.