Cambridge used to clean the streets once a month from April to
November. A couple of years ago, they extended that, and now
they clean in December as well.
I was chatting about that with a group of longtime Cambridge
residents, and one of them stated as an absolute fact that this
was because of global warming — that the leaves used to be
finished falling by November, but now they’re still falling so
they need to do the last streetcleaning later. She might have
expanded this theory to include that another reason they don’t
clean in the winter months is that it can’t be done with deep
piles of snow in at the sides of the streets, and global warming
might have led to fewer large snowstorms in December.
Someone who was on the City Council or in the Department of
Public Works might be able to answer this question
definitively. My impression is that the streets always had
leaves in them all through the winter because of the ones that
fell or blew after the November cleaning, and what’s changed is
the demographics of Cambridge residents, who are now more likely
to complain about leaves in the gutters.
New England weather is so erratic that I don’t think a
climatologist would really care to predict the effect of global
warming on the amount of snow in December. It wouldn’t surprise
me at all if it went up instead of down.