Come to think of it, I've never heard of a movement to dust off plants that might have accumulated debris from sand storms or volcanic eruptions. Neither does anyone seem to be in charge of raking the leaves that fall off trees in the Earth's rainforests. And don't get me started on the lack of rock scrubbing. Have you seen that nasty lichen that grows on unattended rocks? Yeech.
The Pope is right. Someone needs to take care of this earth before it looks like squatters have taken residence.