In dust tree

Ok. I'm being facetious but as well as that when I was doing this I was thinking about how the tree resembled clouds, clouds of dust and ash that came from heavy industry and how these toxic clouds still pollute our air. We're addressing the issue of air pollution in this country but when I was in London this weekend I read that it is still the most air polluted city in Europe.
Trees cleanse the air we breathe and yet we STILL persist in destroying vast forests.
To quote Cpl Jones in Dad's Army, I'm afraid we're doomed.
Very afraid.