Deforestation and global warming collaborate
The second is the loss of the Amazonian rain forest. Deforestation is drying it out, and when it reaches a tipping point, there will be no going back. (We’re in the lucky generation that gets to watch Bolsonaro making it happen. On purpose.)
…with a significant loss of trees, less water will enter the atmosphere so areas of the Amazon will become drier and drier as the water cycle breaks down. This is already happening in the southern and eastern Amazon, where dry seasons have become longer for at least the past 2 decades.
Global warming will intensify this damage. Along with deforestation, it will lead to increased forest fires, regional droughts and flooding, and biodiversity loss.
The Amazon will pass a tipping point when the water cycle is so badly ruined that areas of the forest stop producing enough rain for a rainforest to grow. It would be permanently lost and transformed into degraded savannas.
TBC
This happened in the West Texas hill country some decades ago. In the 1950’s, near the end of nearly a century of deforestation of the live oaks and black walnuts and over-grazing of the grassland the small creeks were still running full and strong year-round on the caliche, but the tipping point had been passed. By 1970 they were running only a few months during the year, and by 1984 when I graduated from high school, the creeks where my father had caught perch every day as a boy had been dry for so long that the scrub brush they call “cedar” down there was growing in the former creek beds so thickly that even the black-tailed deer couldn’t get through.
A good rule of thumb: trees bring rain. Deserts have higher albedo or reflectivity than do forests, so Bolsonaro’s logging teams are helping to turn Amazonia drier and prone to wider diurnal temperature ranges in the short term: which latter is all that usually matters to the Bolsonaros of the world. When one location is mined out, they just move on.
The Danube used to freeze over in the first century C.E. (as reported by contemporaneous writers), before the vast primeval European forests were largely chopped down. IIRC, there were histories of barbarians crossing the Danube in the winter, on foot & horse. (It’s been some years since I read those things, so my apologies for not naming the writers.) I imagine that the colder temperatures of that time had less to do with the albedo of the forests than with the moisture-harboring nature of such forests. Or perhaps those histories were just one-offs and I’m babbling; both are possible.