Any mentions of Environmental protection in Bible? Is there any practical references about environmental protection as well as protection of earth? Whether Jesus mentioned about any of these topics somewhere?
If you search on Google with keywords like "bible environmental", you will get many sites which claim that the Bible supports the idea of Environmental Protection.  EarthCare has a good summary of relevant verses on environmental care, some of them are...


  Command to Care for Creation
  
  "The Lord God took the man and put him in the Garden of Eden to work
  it and take care of it." (Genesis 2:15)
  
  "The land itself must observe a sabbath to the Lord. For six years sow
  your fields, and for six years prune your vineyards and garner their
  crops. But in the seventh year the land is to have a sabbath of rest,
  a sabbath to the Lord.... The land is to have a year of rest."
  (Leviticus 25:2-5; cf. Exodus 23:10-11)
  
  "You shall not pollute the land in which you live.... You shall not
  defile the land in which you live, in which I also dwell; for I the
  LORD dwell among the Israelites." (Numbers 35:33-34)
  
  "If you besiege a town for a long time, making war against it in order
  to take it, you must not destroy its trees by wielding an ax against
  them. Although you may take food from them, you must not cut them
  down. Are trees in the field human beings that they should come under
  siege from you?" (Deuteronomy 20:19)


However, these verses are not directly referring to environmental protection, though they can be put forth for the argument.

Keep your Temporary Home clean: 
The earth belongs to us and we must take care of it, not because God commanded us to do it so. This is a secular matter. Though we will stay here only for a while, lets take care of this Temporary Home. It would be a foolish thing to pollute our home.

Can we really take care of the Earth? NO! It is in God's care. God created this world according to His will and will destroy it again by the same will. No matter how hard we try to preserve the environment and wild life, God is going to destroy this earth by fire anyway on the Day of Judgement. In that sense, it might be pointless to strive hard in protecting the environment.


  2 Peter 3:3-7 (NIV) 
  
  Above all, you must understand that in the last days scoffers will
  come, scoffing and following their own evil desires.They will say,
  “Where is this ‘coming’ he promised? Ever since our ancestors died,
  everything goes on as it has since the beginning of creation.” But
  they deliberately forget that long ago by God’s word the heavens came
  into being and the earth was formed out of water and by water. By
  these waters also the world of that time was deluged and destroyed.
  By the same word the present heavens and earth are reserved for fire,
  being kept for the day of judgment and destruction of the ungodly.


God will destroy this present world by fire and will create a new Heaven and Earth, a new Earth far far better than the present.


  Revelation 21:1 (NIV)
  Then I saw “a new heaven and a new earth,” for the first heaven and
  the first earth had passed away, and there was no longer any sea.


We are not permanent on this earth, we have a destination ahead. We must not set our hearts on this world because we are only travelers here. 


  1 John 2:15 (NKJV)
  Do not love the world or the things in the world. If anyone loves the
  world, the love of the Father is not in him.


Conclusion: If you want to protect the environment, go do it. There is nothing wrong in it. It's a good thing. It proves that you are a good human. Only good people think about those things and only fools neglect them. But please, do not include Christianity to the context. Don't try to relate them. Does that mean we should start polluting the environment? Not at all! Only foolish people would do that.