Filmmakers Ha Uyen, Huong Tra, Quang Dung and Quang Phuc created the documentary. Connect4Climate (www.connect4climate.org), the global climate change communications programme, launched the Action4Climate competition in early 2014.

The World Bank Group and the Italian Ministry of the Environment funded the contest, which attracted hundreds of entries from around the world. Italian film director and screenwriter Bernardo Bertolucci chaired a renowned jury of filmmakers tasked with choosing winning films in two age categories.

In the 18- to 35-year-old category, the US$15,000 top prize went to Gonçalo Tocha of Portugal for his provocative film, The Trail of a Tale. This inspiring story revolves around a letter written in the future and addressed to society today.

Dobrin Kashavelov of Bulgaria won second place and a $10,000 cash prize for Global Warning, a harrowing film about the catastrophic effects of last year's super typhoon Haiyan on survivors in the Philippines.

Nathan Dappen of the US won third place and a $5,000 cash prize for Snows of the Nile, a documentary following his adventures as he uncovers indisputable evidence of the fast-fading glaciers of Uganda's "mountains of the moon".

In the 14- to 17-year-old category, The Violin Player took top spot. This beautifully animated film was the brainchild of Francina Ramos of Argentina and her co-producer and composer Benjamin Braceras.

Facing the Flood, an investigative account of changing conditions in Greenland and the Maldives by Constantin Huet of Switzerland, won second place. It's Easy if You Try, a whimsical film by Tura Tegerashivili of Georgia, won third place.

All winning films can be viewed at www.Action4Climate.org.