Climate change doesn't necessarily occur in a gradual, linear way

Probably one of the most important ideas to understand about climate impact modelling: small changes to the mean equate to huge changes on the tail of the distribution. And that distribution over time has direct causal links to the health and viability of all biological lifeforms.

We can talk about a 1.5 C degree rise in global temperature. Using Kelvin (which has an absolute zero), this represents a change from ~290K to 291.5K - a 0.5% change. Big deal, right? Not even a percent difference.

But life doesn't seem to be concerned with "average" temperatures.

If we look at other metrics like the frequency of days with wet-bulb temperatures above a certain threshold, or the number of contiguous frost-free days, or the bioclimatic envelope of species - metrics that incorporate time as well as biological thresholds that are causally related to species health and spatial distribution - we see that the impacts of climate change are far more pronounced. Large and measurable multi-percentage point changes already. The response of biologically-relevant variables is quite obviously non-linear compared to the temperature rise.

In some cases, the frequency of these "extreme" events now occurs so regularly that they are no longer considered extreme. The baseline has shifted so rapidly, in my lifetime, that the conditions of a stable Holocene climate might as well be an ancient mythology.

This fact is going to make a lot of people unhappy.

20 meters of sea level rise over 100 years (or whatever) doesn't mean 0.2 meters per year. It might mean none for 20 years, then 4 meters in a short period of time.

The future is going to be ugly.

Climate change events cascade rapidly;

Last year, the Siberian Forest fires led to intense heat in the permafrost, melting it for the foreseeable future, reduce cold heat sink.

Flooding last year (and this year) in Europe and the US will lead to rebuilding, which requires energy and supplies;

This year the Canadian forest fires will increase the temperatures and particulate in North America and likely the arctic cirle.

Then the Gulf of Mexico (and Atlantic) are hotter and more acidic than in recorded history; coordinated with less air movement from the jet stream. Which is likely to lead to more hurricanes, which will have increased energy expenditures to rebuild.

Climate change isn't linear; it's exponential.

I've heard that recent changes to reduce sulfur emissions from maritime shipping have caused a sharp increase in global warming:

https://twitter.com/RokoMijic/status/1674697743380430849

https://twitter.com/RandomSprint/status/1679851033424547840

I really don't like this take. Of "climate change is vague, and unmeasurable, and literally every severe weather event will be blamed on it".

There is a very simple graph at https://gml.noaa.gov/ccgg/trends/ that shows a very linear trend.