Windy offers a CO layer i.e. carbon monoxide (but not CO2)
The concentration forecast of CO is provided by the NASA: https://earthobservatory.nasa.gov/global-maps/MOP_CO_M
It must be pointed out that the resolution of the model (22km) and the long step update (55hrs) do not allow to consider these maps as an alert mean.
@beardedcook I thought the same too, but you can get back to regular 2D mode. On the map controls underneath the zoom in and out + and - buttons when you are in 3D mode you will see an extra button labelled 2D to get back into 2D mode.
I agree though that the user interface would be nicer if there was a toggle somewhere instead of one place to switch to 3D mode, and a different place to switch to 2D mode.