A study from Wisconsin found that nearly 60% of the annual phosphorous in urban water systems is from these falling leaves, or so-called "leaf litter." But it's not all bad news! The same study ...

“We call it fall because leaf fall down ... poets’ fascination with “the fall of the leaves” in autumn turned “fall” into another way of saying autumn by the 1600s.

Autumn is rapidly approaching ... been arriving later across Europe since the 1980s, and in Britain oak leaves are falling a week later than 30 years ago. Fall is not an exclusively US term.