Climatic changes are slow on the scale of human lifetimes, with the exceptions of the effects of volcanic eruptions and asteroid impacts - and in terms of human

Climatic changes are slow on the scale of human lifetimes, with the exceptions of the effects of volcanic eruptions and asteroid impacts - and in terms of human history, those latter effects are typically transient. E.g. the Pinatubo explosion did lead to a short-term cooling impact in the 1990s, but it only lasted seven years or so (although it was a good experiment test of climate model theory, as the effects of the aerosol injection were predicted with good accuracy, such as a slight reduction in atmospheric water vapor). Most of the major impacts of climate changes took place over thousands of years, such as the wet period in the Sahara (which once hosted a sizable human population). Both the transition to wet conditions (14-15 kya) and the drying out(5-6 kya) took place over a roughly thousand year period: https://en.wikipedia.org/wiki/African_humid_period https://en.wikipedia.org/wiki/African_humid_period Given that our modern understanding of the effects of CO2 and other IR-absorbing gases on global temperatures was worked out by 1980 or so, and that the 40-yr period since then has seen a globally averaged deltaT of +0.4 C, it's interesting to see that global fossil fuel production (annual) has doubled since 1980. This has been matched by the increase of atmospheric CO2 from ~1.6 ppm per year (1980) to ~2.4 ppm per year (2020). Humans, it seems, are rather incapable of long-term planning (regardless of ideology, the socialist countries produce fossil fuels at the same rate as the capitalist countries): https://research.noaa.gov/article/ArtMID/587/ArticleID/2636/Rise-of-carbon-dioxide-unabated https://research.noaa.gov/article/ArtMID/587/ArticleID/2636/... However, if you ask most people who remember the climate conditions in 1980 if there's been any dramatic world-altering change since then, they might point to more frequent wildfires, droughts, floods etc. but in terms of world-shaking events (e.g. WWII, etc.) it hasn't impacted people's lives to the same degree. Furthermore, the politicians who've tried to make this an issue in elections have turned out to be the very same politicians who work for the fossil fuel industry to expand production (see Obama and the expansion of domestic fracking of natural gas in the USA 2008-2016 etc.). This makes a mockery of much of political climate activism - and in particular, the claim that 'we need to act now!' is pretty nonsensical. Current rates of warming will proceed for the next 100 years even if we eliminate fossil fuels overnight (and all fossil producers seem to have plans to maintain current levels of production for the next 30 years, so...). All in all, the current fossil fuel-forced climate transition will place new pressures on human civilizations but whether or not that leads to global war, mass migration, genocidal conflict etc. will depend more on human behavioral choices than on climate science. Of course, we do have the technology today to replace say 3% of fossil fuel consumption with renewables per year, which would eliminate fossil fuel production in 35 years, but this would make fossil fuel producers (and their economic dependents) very sad... and we'll still have to deal with new climate conditions.