[ad404b8a372f2b9]

It's not a good thing because people have no intuitive understanding of ppm, unlike temperature. PPM can only be judged according to another measure (second y-axis) or in comparison to itself, in which case you want the comparison to be accurate. That means making a graph that starts at 0 so the ratio is self-evident by eye, here it presents an 8-fold increase instead of a <2-fold increase.

[markhahn]

I wonder why you think PPM is not well-understood.

if anything, for normies, temperature is far less well understood than concentration, especially WRT zero.

[shadowgovt]

Honestly, for the topic at hand, none of these are useful.

What we need is a bright horizontal line that says ">50% chance your society collapses in the lifetime of your children", one that says ">50% chance your society collapses in your lifetime", and one that says ">50% chance your species does not survive 100 years." To properly frame the stakes and the significance of the numbers.

[ben_w]

> ">50% chance your society collapses in the lifetime of your children"

That's not far from the default for all of us anyway, isn't it?

Soviet Union fell apart in my lifetime; my parents were born during and just before WW2, got to see the Winds of Change.

I'm not sure about my grandparents, other than one grandmother's funeral anecdote being that she wandered off unsupervised as an infant, which had the people looking after her scared she had been eaten by a tiger because this was in a military camp in the British Raj.

No Ottoman empire, no Austro-Hungarians, and the borders of the Germany I moved to no longer go as far as what's now Калининград.