Bernice looks at black carbon in the snow of the Himalayas

While forests only cover 16 percent of Australia's land area, they harbour a higher concentration of animal species than anywhere else on the continent.

These sets of islands are some of the most far flung territories of Australia, but they possess captivating natural beauty and a surprisingly rich and diverse past, with a multicultural heritage like no other. Charles Darwin spent time on Cocos Island developing his theory of coral atolls - a beautiful spot for some theorising, and now as one of Australia's most north easterly points it is of huge military significance. HMAS Sydney sunk the German destroy SMS Emden in World War I not far from Cocos as a German raiding party was attempting to sever Australian communication lines, Neil discovers the story of how this party - the only survivors of the Emden - 'borrowed' some local boats and made the long journey back to Europe. Have you heard the one about the wasp that kills the bug that feeds the ants that kill the red crabs that keep the forests healthy on Christmas Island? Emma has, and lets us in on the ecological battle for equilibrium on the jungle floor. And Dave joins the forensic hunt for the identification of an unknown soldier, washed up on Cocos island in Australian Navy uniform in World War II.

Millie Ross visits an Indigenous plant propagation expert; Costa Georgiadis creates a polystyrene palace for worms; Jerry Coleby-Williams dives into the war on weeds; Jane Edmanson visits a fruitful family farm.