Let's build a flat scaled model of our earth
A cylinder 10 mt diameter and 0.25 mt height , full of air
Big cities such as New York, London, Paris etc are small circles abt 0.5 cm diameter
The total surface of the big and the small circles is less than 0.01% of the surface of the earth
The circles emit some smoke
If your model is realistic you need a magnifying glass to see it
Well catastrophic ecologists claim that this smoke can modify the climate inside the cylinder
I have some doubt