Clarke may have incurred a huge personal loss in last season's finale of "The 100" but that will not stop her from stepping up once again to save as many people as she can against a threat that could put humans into extinction.
Before her goodbye to "The 100" last season, ALIE (Erica Cerra) revealed that she left a parting gift to the survivors. According to TV Line , she said that the Earth will be habitable for only six months more. It means that the remaining humans can only survive within the same period and not a second later.
In the coming "The 100" Season 4, Clarke (Eliza Taylor) will once again take on the new threat to her people's survival. But, many of them will lose hope for surviving the latest threat. Some however will choose to live life to the fullest in what seems to be their remaining days. Another difficult challenge for Clarke therefore besides saving the people is to convince the hopeless of the lot to trust her for the last time.
Besides being able to survive another catastrophe, other characters in "The 100" Season 4 have their own personal battles to face as well. Octavia (Marie Avgeropoulos) will remain dark as she can't move on from Lincoln's (Ricky Whittle) death. Getting over it is made more difficult with the knowledge that her own brother Bellamy (Bob Morley) was indirectly involved in Lincoln's death.
For his part, Bellamy will try everything to redeem himself and win his sister over in "The 100" Season 4. It might prove to be a lot difficult considering that he has to do this while helping Clarke save the lives of their people. But, it may not be Clarke who can save Earth and its remaining people.
According to "The 100" spoilers for the new season, it will be Raven (Lindsey Morgan) and not Clarke who the Sky people will be turning to. According to Variety, due to her close encounter with ALIE last season, ALIE left something of her behind in Morgan making her smarter, having the ability to code and being able to understand Becca's work that no one else can.
Raven is being dubbed as the new savior of the doomed human race because of the new power she has. She and Clarke will definitely need them to help their people survive the apocalypse. How Clarke and Raven will be able to do that still remains to be seen when "The 100" Season 4 premieres on a still unannounced date.