Ice & the Sky documentary review ★★★★★

Presenting the film out of competition at Cannes, Oscar winning March of the Penguins director Luc Jacquet's new documentary about climate change takes a surprisingly gentle approach to an often sensationally treated topic. New documentary Ice and the Sky (La Glace et Le Ciel) addresses global warming from the perspective of one of the first scientists to explore the Antarctic – and the man who first called attention to the crisis.

The documentary follows glaciologist Claude Lorius as he investigates the glaciers of the Antarctic. He is looking for clues to suggest how the world's climate has changed in 400,000 years, through ancient secrets hidden deep below the surface of the ice. The film makes use of a wealth of original footage, from Lorius' first expedition to the Antarctic in 1957 right up until the present day, remarkably catalogued and beautifully preserved.

Narrated by Lorius, Ice and the Sky is an astonishing piece of work as we observe the groundbreaking scientist at every stage of his fascinating career. Now in his eighties, Lorius returns to the sites of his early expeditions, gazing wistfully around at the vast frozen sheets surrounding him.

The excitement with which Lorius looks back on his idealistic younger self and his groundbreaking work is palpable – and infectious. In one archive scene from his first expedition, Lorius and his team of explorers find themselves trapped in violent snowstorms, the film shifting from tense adventure to seat-gripping thriller, enhanced by stunning cinematography – all, amazingly shot on Lorius' handheld, vintage camera.

As with March of the Penguins, the narration in Jacquet's new project is dramatically charged – the vast sweeping aerial photography of the modern day footage hugely cinematic. We hear Lorius reflecting on his experiences with considered poeticism as he recalls a life rife with adventure. Jacquet paints Lorius as the essence of 'cool' – a perspective rarely granted to those of his profession.

One brilliant moment comes when Lorius and his fellow explorers arrive at a previously uncharted area of land, only to find their way is blocked by a vast mountain. They must scale it – and Claude subsequently names it 'Mount Lorius', he says, 'like children playing at explorers'. Lorius expresses his astonishment that that maps of Antarctic still hold this title; that the chartographers took the 'game' seriously. One of the film's main subtleties is the way Lorius oscillates between humility and self-acknowledgement of these impactful years of meticulous research.

The final shot sees Lorius sitting alone on an iceberg, a single speck of colour in a sea of white, as the camera pans out – poignantly symbolising one man's isolation in his prescience about the impact of global warming, in the face of those who would deny his ideas.

The film gives a final sense of a life's work devoted to a single cause, not fully acknowledged on a global scale, beautifully presented with a sense of nostalgia through its narrator and his grainy archive footage. The film stands head-on against global refusal to acknowledge, and resistance to address, the dangerous incline of global warming. An urgent subject, sensitively drawn and beautifully shot, Jacquet's Ice and the Sky doesn't resort to emotional baiting or political diatribe – it simply lets the science speak for itself.

Ice and the Sky is in UK cinemas and on VOD 11 December