Learn to sing Yismchu Hashamayim

This verse comes from the 96th Psalm. It talks about how all of nature and creation rejoice because God is coming to judge the earth. Our usual understanding of judgment would bring us to expect fear. Why are all of nature's wonders rejoicing?
Because, ultimately, the fact that there is a fair Judge of All Mankind is ultimately a cause of great rejoicing. Otherwise, the world would be filled with anarchy and cruelty. The fact that there is a Judge and that there is justice is a comfort to every being, human and otherwise.