an ecosystem predicted to collapse in the 2090s owing to the creeping rise of a single source of stress, such as global temperatures, could, in a worst-case scenario, collapse in the 2030s once we factor in other issues like extreme rainfall, pollution, or a sudden spike in natural resource use.
There is no way to restore collapsed ecosystems within any reasonable timeframe. There are no ecological bailouts. In the financial vernacular, we will just have to take the hit.
Since climate change figures are a collection of waveforms with short cycles and high amplitude, it is possible that the conditions for a comfortable living environment for humankind could be exceeded temporarily at any moment. And even a temporary exceedance of the allowable value will surely result in loss of human life.
Hundreds died within a week in BC, Canada during a wet bulb event. https://www.cbc.ca/news/canada/british-columbia/heat-death-accountability-1.6093966
A temporary exceeding of the human ability to evaporate sweat and other heat related issues caused 719 deaths, triple the amount of deaths average for that week.