According to the UNFCCC as of today (23rd September 2016) 62 countries representing 49.3% of global CO2 emissions have now ratified the Paris Agreement. To enter into force the agreement needs 50 countries representing 55% of global emissions to sign. So milestone one has been passed and milestone 2 is close to being achieved.
At a single event hosted by the UN on 21st September 2016 31 countries signed up in one day. The UN says that 14 more countries have indicated they will sign before the end of 2016 which will take the deal past the second milestone.