UNHCR says wars in Syria and elsewhere lifted migration as thousands who died during perilous journeys are remembered.
The number of people fleeing war and violence in 2015 is likely to break all previous records, with almost a million people having crossed the Mediterranean escaping conflict in Syria and elsewhere, the UN refugee agency has said.
In a report released on Friday, the UNHCR said that the global refugee total, which a year ago was 19.5 million, had as of mid-2015 passed the 20 million threshold for the first time since 1992.
Asylum applications, meanwhile, were up 78 percent at 993,600 over the same period in 2014.
"Forced displacement is now profoundly affecting our times. It touches the lives of millions of our fellow human beings both those forced to flee and those who provide them with shelter and protection," Antonio Guterres, the high commissioner for refugees, said.
"Never has there been a greater need for tolerance, compassion and solidarity with people who have lost everything," he added.
Unprecedented numbers of refugees travelled to Europe this year. Some 84 percent came to Europe from Syria, Afghanistan, Eritrea, Somalia, and Iraq, according to UNHCR figures.
The report came as rights groups, charities and global organisations marked International Migrants Day by remembering the thousands of refugees and migrants who have died during perilous journeys this year.
In a message posted on the United Nations website on Friday, Ban Ki-moon, the UN secretary-general, said: "2015 will be remembered as a year of human suffering and migrant tragedies."
He added that in total, more than 5,000 women, men and children had lost their lives this year "in search of protection and a better life".
"Tens of thousands more have been exploited and abused by human traffickers. And millions have been made into scapegoats and become the targets of xenophobic policies and alarmist rhetoric," said Ban, as he called for safer channels for migration.
By mid-November, more than 800,000 refugees had reached Italy and Greece, with smaller numbers arriving in Spain and Malta, according to Human Rights Watch.
While International Migrants Day increases the visibility of those in vulnerable situations, "it shouldn't just be on one day that people care or that decision-makers think about the right kind of policy to implement", Judith Sutherland, associate Europe and Central Asia director at Human Rights Watch, told Al Jazeera.
She added that greater recognition for the right to seek asylum, safer and legal channels for people to be able to reach the continent without resorting to smugglers, better resettlement programmes, humanitarian visas, and increased family reunification would help to stop people from dying on their way to Europe.
Improved treatment and policies should also be put in place for economic migrants, said Sutherland.
"People who take journeys to improve their lives and pursue economic opportunities are fleeing things like bad governance, corruption and poverty," she said. "There needs to be a much more rational debate and steps taken towards improving legal migration for work."
Dead and missing
At least 3,695 people were reported to have died or gone missing in the Mediterranean between January 1 and December 18, 2015, according to the International Organisation of Migrants.
The IOM called on the international community to "come together and remember the refugees and migrants who have tragically lost their lives this year" as it promoted a worldwide candelight vigil.
The group also launched a campaign, 'I am a Migrant', which tells the stories of individual refugees and migrants "to remind the world" of their value.
One of those refugees whose story of migration has been shared is Zina, an Iraqi who fled to Jordan to escape war and violence.
She left her country of origin in 2010 after a car bomb targeted a television station next to her house.
"I had just left my house to go to work when I heard a huge explosion. All I could think about was my son, still asleep in the house. He was only 13 at the time. He got injured and was unable to move for weeks. I decided I had to take my children out of the country," she said.
"In my spare time, my friends and I help the Iraqi migrants who are less established here. I will never forget how hard it was to be new in the country and I want to do everything in my power to help others in this situation."
The International Labour Organisation (ILO), meanwhile, celebrated the 40th anniversary of a convention to protect migrants from abusive conditions and promote the equality of opportunity, adopted in 1975.
"The vast majority of migrants migrate in search of better job opportunities," said Manuela Tomei, director of the ILO's conditions of work and equality department.