The heart of the global-warming documentary “Chasing Ice” is a remarkably beautiful and remarkably disturbing series of sequences - time-lapse footage of huge segments of glaciers collapsing and melting away. The idea is to present striking visual evidence that climate change has accelerated dangerously and drastic action is needed.

The footage is the work of photojournalist James Balog, who saw glacial melting in Iceland while on assignment in 2005 for National Geographic, and two years later founded the Extreme Ice Survey to provide compelling documentation of the phenomenon, from Iceland and elsewhere. “Chasing Ice,” directed by Jeff Orlowski, follows Balog’s efforts to set up the survey, a huge undertaking, and shows us some of the results.

Balog and his team set up still cameras in Alaska, Greenland and other appropriate spots and rigged them to take shots at regular intervals. The process was arduous, not only because of the remote locations, but because the crews had to improvise technology to withstand the harsh conditions, and Balog had severe knee problems.

The scale of the glaciers, and the almost hallucinogenic clarity of the images, make the resulting footage, based on three years’ shooting, most impressive. One piece of ice we see breaking off is said to be the size of Lower Manhattan. Balog remarks that the ice masses he photographs are as individual as human faces, and what we see sometimes does resemble portraiture.

The film’s long setup includes the requisite talking heads and visual aids (charts, graphs) to explain why the melting of the glaciers is worrisome.

Though only 76 minutes, “Chasing Ice” seems to take a long time before finally showing us the footage it’s setting us up for, and as arresting as the images are, they seem in short supply. Instead, there’s screen time at the end devoted to Balog presenting his findings in a lecture setting.

His personal efforts are praiseworthy, but if glacial melting is in fact the “canary in the climate coal mine” (his words), the movie might have given us a bit less of Balog and a bit more of the startling sequences he produced.