if all authority is given to Jesus in heaven, who has authority on earth ?

And Jesus came up and spoke to them, saying, “All authority has been given to Me in heaven and on earth." Matthew 28:18

According to Jesus his authority isn't limited to heaven. His authority includes earth as well. However that doesn't mean that evil forces will not challenge him. 

Matthew 28:18  And Jesus coming, spoke to them, saying: All power is given to me in heaven and in earth. 

The governments of men. 

Mt. 28:18 is all about authority.  So is Psalm 33:9, 6.  So is Psalm 66:7, 90:2.

The Apostles and Prophets, and since they have passed on, then their word which has been preserved and come down to us.

The jehovah's witnesses cult leaders, so they claim.

Very close to what "Pete" said....It's the Adversary

2 Cor 4:4 - In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them.

John 3:35

35 The Father loveth the Son, and hath given all things into his hand

John 5:22

22 For the Father judgeth no man, but hath committed all judgment unto the Son:

Romans 14:9

9 For to this end Christ both died, and rose, and revived, that he might be Lord both of the dead and living.

Revelation 1:18

18 I am he that liveth, and was dead; and, behold, I am alive for evermore, Amen; and have the keys of hell and of death.

The government.