It tends to be overlooked that climate change has impacted civilisations in the past. In no particular order:

Around 900 CE, things started to go wrong for the Mayans. Overpopulation put too great a strain on resources. Increased competition for resources was bringing the Maya into violent conflict with other nations. An extensive period of drought sounded the death-knell, ruining crops and cutting off drinking water supplies.
More than 4,000 years ago in Mesopotamia – the area currently made up of Iraq, north-east Syria and south-east Turkey – the Akkadian empire ruled supreme. Until a 300-year-long drought quite literally turned all their plans to dust.
the Khmer empire of south-east Asia, which flourished between 802 and 1431 CE. It too was brought down by drought, interspersed with violent monsoon rains, against the backdrop of a changing climate.
Even the Viking settlers of Greenland, in the far north Atlantic, are believed to have been affected by climate change. Some 5,000 settlers made the island their home for around 500 years. But they may have had their way of life disrupted by climate change. Temperatures dropped, reducing substantially the productivity of their farms and making it harder to raise livestock. They adapted their eating habits, turning their attention to the sea as a source of food. But life on Greenland became unbearably difficult, leading to the eventual abandonment of the island colony.
The rapid decline of the Anasazi empire in the SW of the US is most widely regarded as being due a great drought, which brought on famine, a theory which would be consistent with archaeological findings of skeletons showing signs of malnutrition, and the abundance of infant and children’s bones.

The link below is quite interesting on the evolution of both the data and interpretation.
https://leilan.yale.edu/sites/default/files/publications/article-specific/weiss_2017_megadrought_collapse_and_causality.pdf

and an interesting wiki article but a bit sparse on sources(unfortunately)
https://en.wikipedia.org/wiki/Climate_oscillation
If you follow these arguments in depth you realize there are uncertainties in the science but one idea to take away is that if human numbers overwhelm resources the outcome has always been collapse. The frequency of famines in history shows that collapse is never that far away, and the link below should give pause for thought.

https://en.wikipedia.org/wiki/Famine#Risk_of_future_famine