Problem words — Since

Since can have an ambiguous meaning when used to describe two consecutive events which may or may not have a causal relationship.

An increase in extinction rate occurred since global temperatures increased.

Here, since is ambiguous because it can have either a temporal meaning or a causal meaning (as a synonym for “because”).

An increase in extinction rate occurred in the period since global temperatures increased.

If the relationship is temporal make this clear (i.e. the increase in extinction rate followed the global temperature increase).

An increase in extinction rate occurred because global temperatures increased.

If the relationship is causal use because (i.e. the increase in extinction rate was caused by the global temperature increase).