The Symptoms of Kali-yuga

After all the impostor kings have been killed, the residents of the cities and towns will feel the breezes carrying the most sacred fragrance of the sandalwood paste and other decorations of Lord Vāsudeva, and their minds will thereby become transcendentally pure. When Lord Vāsudeva, the Supreme Personality of Godhead, appears in their hearts in His transcendental form of goodness, the remaining citizens will abundantly repopulate the earth. When the Supreme Lord has appeared on earth as Kalki, the maintainer of religion, Satya-yuga will begin, and human society will bring forth progeny in the mode of goodness. (Srimad Bhagavatam 12.2.21-23)