Pollution and Butterflies: A Bit of a Stretch?

I know that it is always good to get publicity for a voluntary programme like the Big Butterfly Count, but suggesting that the Covid-19 lock-down reductions in pollution could markedly increase butterfly numbers is something of a jump. Dragging out the tale of Industrial melanisation and the Peppered moth (Biston betullaria) seems a bit of a red herring. The story goes that regular Peppered moths seemed to be well-camouflaged, when sitting on lichen-covered tree trunks, enabling them to avoid bird predators. An occasional  variant, the melanic (completely black) form was more conspicuous and was swiftly eliminated. During the Industrial Revolution, in places like Birmingham, the soot emitted from factory chimneys coated the tree trunks, killing the lichen and turning the surfaces black. Now, the melanic variant was the more cryptic and its numbers increased (this was tentatively said to be evident in museum collections) in comparison to the peppered form. Later, the Clean Air Act, returned the trees and the moths back to the original situation. The things to note, however, are that 1) these changes took decades (not months) and 2) pollution can have much wider effects than simply altering crypsis (it can poison animals and the plants on which their larvae depend). Other aspects of lock-down (e.g. reduced road traffic and spending more time in local environments) seem likely to have bigger impacts on numbers of butterflies recorded.