"The 100" Season 4 will bring together Bellarke, the team-up of Clarke and Bellamy as they work together to survive the impending environmental apocalypse. Moreover, The CW released a new trailer, which is more upbeat than previous ones, despite the threat of the end of the world and more clashes among the tribes.

"The 100" Season 4 will put the delinquents and the Grounders facing a new threat, the environmental apocalypse, as opposed to the tribal clashes that were the major theme in the previous seasons. The new threat will also reunite Bellarke as Clarke (Eliza Taylor) and Bellamy (Bob Morley) work together to survive the looming nuclear apocalypse.

Clarke's leadership will be tested as to how she will handle informing and rallying the people to face the coming nuclear radiation that will make 96 percent of the Earth habitable. She will find a confidante and support in Bellamy in "The 100" Season 4 despite the fact that the two have been in opposite ideological end in Season 3.

Bellarke is at their best when they work together for Clarke's penchant for tough love makes her a ruthless leader easily swayed into the wrong path. Meanwhile, Bellamy's team player attribute is of no value when he is fighting with the wrong team. In "The 100" Season 4, Clarke and Bellamy's friendship will play a pivotal role in their survival as both will work together to save as many people as they can.

Showrunner Jason Rothenberg revealed that "The 100" Season 4 will not focus on romance, but more on survival. However, he claims that relationships will naturally deepen as people cling to their loved ones more when the end of the world is near, the EW reported.

In "The 100" Season 4, viewers will also witness the deepening relationhsip of Kane (Henry Ian Cusick) and Abby (Paige Turco) including that of Monty (Christopher Larkin) and Harper (Chelsey Reist) and Murphy (Richard Harmon) and Emori (Luisa D'Oliveira). Though many fans hope that Bellarke will blossom into a romantic relationship, there is no denying that Clarke and Bellamy's relationship will balance both of their extreme traits, according to Inverse.

Meanwhile, The CW has just released a new trailer for "The 100" Season 4, which is surprisingly more upbeat than previous ones. The same theme of tribal clashes, radiation threat and all-out violence still remain, but the use of the song "Blood in the Cut" by K. Flay adds to its upbeat mood, Den of Geek has learned. "The 100" Season 4 returns on Feb. 1 at 9 p.m. on The CW.