Sheffield's documentary festival: Reflections in a dark mirror

If you can't afford a ticket to ride around the world, there is another way. You can tour the craters of Baghdad, the swelling skylines of China, and the mud villages of Senegal from a cinema seat at the Sheffield International Documentary Festival.

There, over the past week, I have been staring – through celluloid glasses – into the eyes of people scattered across the earth. Even the best print journalists cannot give you the immediacy of a great documentary: of feeling you are walking through the shrieking metal factories in China that manufacture almost everything you own in the film 24 City, or trudging through the vast sink-estates where the British ghettoise the poor in Sighthill Stories.

But the films that riveted me most were the stories of people embarked on their own epic journeys – from country to city, from exile to home, from Africa on capsizing boats to the shores of Europe. The most devastating is the film Life After the Fall, which takes us home with an Iraqi exile – then makes us watch as the home is burnt down. Kasim Abid fled Saddam's goons in 1974, and returned three decades later after the Anglo-American invasion. At first, this is a family reunion film. He embraces the brothers and sisters he has not seen in so long to find that war and sanctions have "turned their hair grey". They explain how the secret police came looking for him, and they were terrified they would pay for his exile. But now they are all filled with "a dreadful sense of hope": Saddam is gone, democracy beckons.

And then the lights go out, and the petrol runs dry, and the tanks keep rolling, and the suicide bombs begin. Kasim and his family stand frozen. "Is this supposed to make Iraqis support them?" Kasim asks, staring on TV at the jigsaw of body parts after a bombing. His camera stays distant, peering at the chaos in long shots, as if paralysed. But the optimism takes a long time to die. The house a few doors away from his sister is blown up by a mysterious package. His niece is in a car that is stopped by gunmen, and one of the passengers is shot. Kasim's coffee is blown out of his hand as he sits at home. They don't talk about it much. They try to continue with normal family life.

After all the headlines, after all the impossible-sounding statistics – a million dead, four million forced from their homes – we finally see what this war has been like for ordinary Iraqis. You are driving to work and you get stuck in traffic – and shooting begins all around you. What do you do? Your child wants to go to school in a country where the sky is scarred black with bomb smoke. What do you do? The US soldiers – glimpsed briefly, peering from tanks – seem like surreal extras from another movie set, stumbling into the streets of Baghdad by mistake.

Slowly, the pools of hope and optimism curdle. The camera pans across acres of rubble as Kasim says: "This is American reconstruction." His nieces – smart, determined young women – find themselves imprisoned in their homes by Islamist militias. "No one has the right to force me to cover my head," one of them says, in despairing anger, before adding: "We might as well be dead, so what's the point of living?" Through it all, the streets of Baghdad have a surreal beauty, with their concrete brutalism and dust storms and groaning rubble.

The war blasts deeper and deeper into the family's life – and then, one day, a gang wearing balaclavas enters the grocery shop run by Kasim's brother Ali. They put a gun to his head as his young son watches, and bundle him into a car. The family waits – one day, two days, seven days. There is no ransom demand. They know Ali had long ago converted to becoming a Sunni, and all over Baghdad, the rival religious sects are slaughtering each other. The family squeezes into the overflowing morgue – and Ali is there. In the chaos, the morgue loses the body. They never get to bury him.

Life After the Fall is a heart-breaking film because it is a heartbroken film. Just before she flees her country, Kasim's sister Ilham sits stunned and says to camera: "After the fall, we would sit on our balcony and talk about the future of Iraq. We had high hopes. My husband used to say – Dubai, the Gulf [states] will be nothing compared to Iraq... But in the end everything failed. We didn't benefit at all. The country didn't get better or rebuilt, it just got destroyed some more."

The Czech film-maker Miloslav Novak has been on a very different journey: to find a creature we are killing. The Mediterranean monk seal is Europe's most endangered species. After 14 million years dappling in our seas, there are fewer than 500 left in the wild, and none in captivity. These odd, wriggling, blubber creatures, with arms like men and snouts like pigs, are about to pass from history. In most wildlife films, the camera is a god, swirling anywhere the wildlife swirls. Not here. In Peace With Seals, Novak has made a wildlife film about his inability to find any wildlife. He trawls Europe trying to find the seals. He tries to lure them with large plastic replicas of female seals, the amphibian equivalent to sex dolls. He interviews elderly seal hunters. But he only ever gets fleeting glimpses of the creatures themselves – and then the seals are gone.

The film becomes a meditation on the great ecological die-off we are living through – and causing. The seals are a seal on our fate, too, he believes. He quotes one of my favourite novels, Karel Capek's The War With the Newts, where humans and amphibians go to war. If this is a war, we have won. Wildlife has lost. And we will pay for our victory. The film ends with a hellish image. In the 1950s, a seal was captured in Sardinia and brought to Rome, where it was made to live in a fountain. Novak imagines the animal flapping in concrete while photographers burst flashes in its face and a crowd of tourists roared its approval. This is what the world looks like now, on a grand scale.

The seals are not the only beings dying in the seas around Europe. The film Barcelona or Die opens in a tiny village in Senegal whose poverty-starved young people dream of sailing to Europe. Every day, tiny, rickety boats stuffed with people set off. Some make it to the Canary Islands and on to their dream city, Barcelona. But many only reach "barca": the afterlife in their language. The few who return tell of how their boats capsized, they watched family members drown and had to drink sea water.

And why? Why do they come? The African village is coming to Europe because Europe has come to their shores – and destroyed their livelihoods. "There's nothing in the sea any more," explains one fisherman. "There was a time when the sea was good, and there were lots of fish... The [huge, industrial European] trawlers put an end to that. It's not right. It's not right that they came here from Europe and took everything. What's left for us?" One of Peter Mandelson's last acts before leaving the European Commission was to try to extend Europe's "right" to Africa's fish. The film ends with hundreds more desperate young people setting off in half-broken boats, to skivvy or to drown.

What do you learn if you watch dozens of movies from every continent in one concentrated burst in the dark? I kept thinking of Salman Rushdie's definition of globalisation: "Everywhere is part of everywhere else now." These stories about Iraq and the shores of the Mediterranean and Senegal are stories that lead directly back to us. Next year, see the world at the Sheffield International Documentary festival – and you will see your own actions staring right back at you.

You can buy the film 'Life After the Fall' at www.lifeafterthefall.com