ToT display weirdness

[Rodgers]

Playing ToT this weekend I noticed in the top left display box (where there is usually a beaker and your gold total, year etc) a yellow-reddish circle that seemed to grow and then contract, eventually dissappearing altogether once I started building solar plants, recylcing centres and mass transits in most of my cities.

Is this some sort of indicator as to proximity of global warming or what? (I never pay attention to that display normally so it could be something much simpler)

 

[Nick]

Yes. The bigger the sun gets the higher the danger of global warming.