Deluge Drivers (Icerigger Trilogy)

It looked as if Ethan Fortune was stuck on the icy world of Tran-ky-ky, never to enjoy the warm comforts of civilization again. But when the scientists at the outpost of Brass Monkey detected an odd atmospheric phenomenon, things began to heat up.
Only the great icerigger Slanderscree could make the dangerous journey to the isolated southern continent, and only Ethan could convince the primitive Tran that the mysterious warm spot was worth the trip. Nothing could have prepared Ethan and his Tran and human companions for what they encountered as they sped southward, for its like had not been seen for thousands of years -- open water on the ice oceans of Tran-ky-ky!
But the worst was yet to come. This was no natural phenomenon. Someone was systematically raising the temperature of the frozen planet. If Ethan and crew of Slanderscree couldn't stop the process, soon Tran-ky-ky would become a paradise for humans -- and a living hell for the Tran.