Except that you can't really say that for certain from the map, either—if all the areas that burned over in 2023 also burned over in 1923, I don't think you would be able to tell. There's no method for indicating that the same area was burned over twice in different years.

(Note: I am not saying that 2023 was not the worst fire year on record for Canada. I am picking holes in this presentation of the information because climate change denialists will do exactly the same thing, given half a chance. Let's create better infographics and not give them an opening.)

I interpreted the map to be non boreal, not unforested. If you look at Northern Québec where it is unforested it's a different shade of grey. I think they could have done better colour selection.