In pictures: World welcomes 2019

Revellers welcome the new year with fireworks display and festivities as a celebratory wave sweeps westward across the globe from Asia to Europe and the Americas at the conclusion of a tumultuous year.

By Hatice Cagla Gunaydin, Baba Umar
Fireworks explode over the Sydney Harbour during New Year's Eve celebrations in Sydney, Australia, on January 1, 2019. / Reuters

Revelers around the globe bid farewell on Monday to a year filled with challenges to many of the world's most basic institutions, including politics, trade, alliances and religion. 

Fireworks, spiritual services and political addresses abounded to mark the transition. 

As the world celebrates, many are wondering whether the turmoil witnessed in 2018 will spill over into the next.

Here is a look at how people are ushering in 2019: