Google announced in February that starting from April 21st 2015, mobile friendliness will be one of the metric to rank websites.
This change will affect mobile searches in all languages worldwide and will have a significant impact in their search results.
Bloggers/Webmasters are advised to make their site mobile friendly in order to still maintain/improve their rankings. If you do not act now, you may loose traffic until their next update.
Is your site mobile friendly? You can Verify Here.