Mass migration is one of the biggest international crises of the last decade, with more people displaced now than at any point since the end of World War 2. As artist and activist Ai Weiwei’s documentary shows, it’s an issue that the western world’s governments have not got to grips with. The human cost of this failure is put forward thoughtfully and affectingly in Human Flow, a slow but vital piece of factual cinema. It’s deeply saddening, but tempered with grace notes of hope and happiness.

This century’s mass movements have been extensively covered in the media, so the tragic causes and infuriating macro statistics are familiar by this point. Human Flow does give a crash course in these numbers, but derives its real power from tiny, individual moments, thrusting a huge range of emotions upon you. On one end of the spectrum, you have a family that’s successfully moved to Europe, their overjoyed baby waving to the camera for the entire interview. Elsewhere, heartbreaking images abound, like that of a Rohingya community leader, brought to tears not by the violence of his past but by the lack of basic respect for his people in press coverage.

In the face of the basic human need on display here, whether it’s in refugee camps, border housing, or on one of the terrifyingly tiny boats in the Mediterranean, the politics of the issue seem utterly ridiculous. That sending people back into the hell that is searching for a nation is a political point-scorer is disgusting, and Weiwei underlines that with furious clarity.

At 140 minutes, Human Flow runs a little long, and there are a few too many superfluous interludes. But that doesn’t stop it from being a very moving piece that will go down as one of 2017’s most important documentaries.

RATING: 4/5

INFORMATION

CAST: Boris Cheshirkov, Princess Dana Firas of Jordan, Marin Din Kajdomcaj, Ahmad Shuja

DIRECTOR: Ai Weiwei

WRITERS: Chin-Chin Yap, Tim Finch, Boris Cheshirkov

SYNOPSIS: Director and artist Ai Weiwei’s detailed and heartbreaking exploration into the global refugee crisis.