"is driven by both overuse and drier and warmer weather."

It wasn't that there is a contradiction. If the over use has been happening for decades, and it's at a rate faster than historical replenishment could happen anyways (before "climate change), then this would indicate that over use is the primary cause. Drier weather is a contributing factor in the pace of depletion, but in no way could be the solitary cause nor cure. Even in the article they mention the demands related to a growing population and industrial agriculture (article also mentions potential food scarcity).