Image copyright Naser jafari / Twitter

It was one of those moments when the whole world seems to care.

On 3 September, a harrowing picture of a 3-year-old Syrian boy, face down on a Turkish beach, who had drowned while trying to reach Europe, was shared by millions on the internet. His name was Alan Kurdi. Tima Kurdi, his aunt who lives in Canada, believes the fact the picture went viral has made a big difference - and in fact, that it saved lives.

"It was something about that picture," she says. "God put the light on that picture to wake up the world."

But is she right about the picture's impact on the world?

Image copyright NAHAR BAHIJ/ TWITTER

On the day it went viral, BBC Trending published a version of photograph, though only illustrations and cartoon versions appear on this page. The original picture shows the lifeless body of Alan Kurdi, who was born to an ethnically Kurdish family in the town of Kobane in northern Syria.

Tima Kurdi never got to meet her nephew Alan face to face, but she was in regular contact with his father - her brother Abdullah. He told her Alan was a "very happy boy, never cried."

Through their many phone conversations, Abdullah told her about the violent civil war in Syria, and about how he first escaped to Turkey on his own, one of around two million Syrians who have fled to the country. And he described how he got his wife Rehana and their two sons, Alan, 3, and Ghalib, 5, to join him there.

Tima had been hoping to bring her brother's family to Canada, but it proved impossible. "One time I said to him, the only option you have try to go to Europe," she recalls. Abdullah heeded the advice - he decided his family would join the 700,000 migrants trying to get from Turkey to the EU this year.

At that time, back in September, there were already signs the debate around refugees in Europe was intensifying and perhaps shifting. The German chancellor had announced a relaxation of refugee rules - resulting in love letters to her from Syrians - and I and the BBC Trending team were noticing that the use of hashtags such as "refugees welcome" was slowly beginning to rise.

On 2 September, we published a post about this build up. On the same morning, Abdullah and his family - who had spent the preceding months trying to make their way to Greece - boarded a smuggler's boat.

Image caption Tima Kurdi spoke to BBC Trending from Canada via Skype

In Canada, Tima waited for a phone call from her brother that never arrived. Instead she got one from another relative who had heard from Abdullah, passing on terrible news. The boat had capsized, killing 12 Syrian migrants including Alan, his brother, and his mother.

Their deaths were just three of thousands of migrant deaths in the Mediterranean this year - most unremarked on. But little Alan's dead body washed up on a Turkish beach, and was captured in a series of pictures by a photographer from a local agency, Dogan News. Some of the photos him face down on the beach, with waves gently washing over him. In another, a policeman gently carries his small lifeless body away.

'Humanity Washed Ashore'

Once posted on Twitter and Facebook, the picture spread fast. In Turkish, 200,000 tweets used the hashtag "Humanity Washed Ashore" - along with another 300,000 in Arabic. And in English, the tag "Refugees Welcome" surged, with 1.5 million new messages.

Image copyright Anssam Gibani / Twitter

A series of debates began about whether to share this graphic image, beginning with pro-refugee campaigners - who had realised that a mood was developing online which they could seize.

"Sharing horrific images can often backfire," says Peter Bouckaert, Emergencies Director of Human Rights Watch, who wrote a blog post on why he felt it was justified to share the picture. "But in this case, I thought it was really important to share this image of a drowned boy because two Alan Kurdis are drowning every day on this journey."

Before long, the debate about showing the picture began in newsrooms - including the BBC's. Some stuck with less graphic shots but a number published the more graphic pictures on their front pages - and before long 80% of the British population had seen it.

Hugh Pinney, from the picture agency Getty Images, says that without social media users sharing it first, it's unlikely that newspapers would have printed it. "The fact that it has been circulating on social media... gave mainstream traditional media editors the courage of their convictions to put this onto the front page and break a huge social taboo. that you simply do not publish pictures of dead children," he says.

After the picture came a number of policy announcements from various countries. British Prime Minister David Cameron said "the whole nation has been deeply moved" by the picture while announcing more help for Syrians in camps, with 20,000 to be resettled in the UK within five years. Meanwhile, ordinary people got involved in charity efforts for Syrian refugees - for example the National Refugee Welcome board, which organised initiatives resulting in 700 landlords offering their houses for migrants and 9,000 people volunteering to foster children.

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At the time, Andrew Mitchell, Conservative MP and former Secretary of State for International Development, accused newspapers who published the picture of "disgusting" sensationalism. He says that despite an increase in refugees being resettled here, the UK in fact stuck to its basic policy position rather than suddenly relaxing its borders.

"What is quite interesting is that now public opinion does not think that that is the answer, and indeed it is not the answer," he says. "The answer is to try and bring a political track so that the fighting stops in Syria."

He's right about UK public opinion - if you look at polls rather than hashtags. In September, after the picture appeared, there was heightened support for allowing more refugees into the UK. But that now looks like a blip, which faded away after the Paris attacks last month - and a clear majority now oppose a rise in numbers.

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Other countries view things differently. Germany had already had adopted a more open policy towards Syrian refugees, and Canada, where Tima Kurdi lives, has now seen its policies shift too. The Canadian government's pledge to take 25,000 Syrian refugees by February may be part of the reason Tima Kurdi now thinks there was something unique about that picture.

"We heard thousands of stories, we saw thousands of pictures of kids dying" before Alan Kurdi's picture, she says. "His older brother lying beside him on that beach, nobody even took a picture of him, nobody even talks about him." She adds: "It was something about that picture, God put the light on that picture to wake up the world."

She is right that Alan Kurdi's picture certainly supplied the image imagery that millions adopted to represent the Syrian refugee crisis - by sharing it on their Facebook and Twitter feeds. In that way, it humanised a crisis that for many seemed rather remote and abstract.

It's much less clear to what extent policies changed as a direct result. And migrants - including children - continue to die trying to cross the Mediterranean.

Image copyright Michael Weiss/ Twitter Image caption Tima Kurdi shared images like this of Alan and Ghalib in happier times

'We are so proud of this picture'

But Tima Kurdi and her brother Abdullah cling on to the idea that their personal tragedy going viral had a positive overall effect. "It is very painful to go through this tragedy, but in other ways. we are so proud of this picture [which] saved thousands of refugees," she says.

And one of those refugees is Tima Kurdi's other brother, Mohammed. Her application to bring him, along his wife and children, recently arrived in Canada.

Alan's father, Abdullah, could also now qualify for refugee status. But without his sons and his wife, he doesn't want to come, and now lives in Iraq.

"So far his answer is - 'I've lost my whole family. The only reason I was going to go to Europe or Canada, was because of them. And now they're gone. Do you think I care about myself, where I going to be?'"

"So I know I want to give him more time," she says. "But so far, he is refusing."

Reporting by Estelle Doyle

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