From most to least.
Climate Change Tipping Point
2023 is the year when climate change appears to have moved from linear to self-reinforcing in a big way. This was the tipping point many of us have been waiting for. Because of how movement between points of stability works, it may flip back and forth a few times, but this is the future. We had 30C weather in the middle of southern winter. Droughts. Vast forest fires. Way less ice in the arctic than their should have been, and so on.
I suspect that the point where we could stop climate change with anything short of massive geo-engineering (and I am not endorsing geo-engineering) is now past. Before, the problem was politics. Now it’s physic, chemistry and biology.
As I always note, environmental collapse is just as important, and 2023 also so a collapse of Alaska fisheries and continued degradation of coral reefs, insects, birds, and pretty much everything else.