For about a year, Google has used your websites mobile friendliness as a factor in ranking searches. Beginning this month, they are taking it one step further. If your websites pages, all pages, are not mobile-optimized, your rank in Google’s search results may drop.
Many are calling this “MobileGeddon 2”. In my opinion, I think we need to rename last years “mobilegedden” to “the shot across the bow”. I feel that in Google’s defense, last years changes was Google giving website owners a heads up that they may want to start making changes to their websites to make them more mobile friendly and offered a small taste as to what the effect may be. Now almost a year later, it think the effect will be much greater if they are looking at each page of your website rather then just the landing page or mobile page. The versatility of a responsive designed website right now is really showing its importance.