I am trying to remember a book I read in my teenage years (so the 1980's) that I thought was called "Ice Planet", but I can't find under that name.
The story is told from the viewpoint of what we later learn is an alien, and the first hint that the planet in question is Earth comes from the statement that it was special because mercury was liquid.
I believe the alien worked for a kind of drug control department to stop smuggling tobacco which had a much stronger effect on aliens than on humans.
Iceworld by Hal Clement
From the description at Goodreads:
Mottled with sinister colors, the planet gleamed in the spacecraft's viewport. Sallman Ken could not believe that such a bleak and icy globe could ever have produced intelligent life. Yet the expedition had contacted natives of some sort when it sent in unmanned landers.
More important, smugglers from his own planet had begun trading with the natives of that Iceworld for a new and virulent narcotic...the most dangerous drug ever to come into their universe.
Now Sallman Ken wondered what manner of creature could exist on a planet so cold that sulfur was a solid, not a gas, and water actually existed as a liquid. But he wouldn't wonder for long, for Ken had to find a way onto the surface of that planet so he could locate the source of that deadly drug.
