It is impossible to truly fathom the totality of the 856,723 people that arrived in Greece by the Aegean Sea in 2015. But this new video from Doctors Without Borders comes close. 

The majority of those people arriving in Greece were Syrian refugees fleeing the country's ongoing civil war.

In this video you can see the life-jackets many of these refugees used piled high, illustrating the number of people that have taken the route and the challenges they face upon reaching Europe. Humanitarian groups are supporting Greek authorities to assist people as they arrive in the country. 

"They don't have a choice. As long as the war is going on people still flee," Kim Clausen of Search and Rescue for Doctors Without Borders, said in the video. "And trying to stop the borders now will only make them do only more dangerous stuff to come, because they are desperate."

More than 800 refugees died making the sea journey last year and more than 300 have already died this year. The video coincides with the campaign #SafePassage for Refugees. The point is simple: refugees are doing whatever it takes to get to Europe, they need support from the international community.

One place keeping out refugees is the country of Macedonia. Fences along the border with Greece have essentially trapped some 7,000 refugees. The situation boiled over in the past few days. Hundreds of refugees pushed through police on Monday, demanding admittance to Macedonia and passage to the rest of Europe.

Refugees must travel through the country, then on to Serbia, Croatia, Slovenia, and finally Austria before reaching Germany - one of the most desirable location for most refugees. Border fences were erected by many of those governments in order to slow down the passage of refugees. The actions are leaving Greece in a bind, argued German Chancelor Angela Merkel.

"Do you seriously believe that all the euro states that last year fought all the way to keep Greece in the eurozone, and we were the strictest, can one year later allow Greece to, in a way, plunge into chaos?" she asked, in a TV interview.

Another crisis summit will take place within a week. Greece will be on the top of the agenda, but the underlying problem is the way that some countries are making it harder for refugees. Belgium, Denmark, and Sweden recently imposed border stops, to keep refugees in check. Austria only allows 80 refugees to pass a day, forming a bottleneck that extends back to Greece.

The real question at the upcoming summit is: Will European leaders support the safe passage of refugees? 

The views expressed here are not necessarily those of each of the partners of Global Citizen.