A lot of these ideas are lovely, but the OPs daughter is 16, seems fairly switched on and is unlikely to accept the babying/placating suggested here.
OP, it’s really hard. The world is utterly dismal at the moment, and on the back of 18 months of pandemic anxiety... your daughter is understandably struggling. I’m an adult with usually fairly manageable OCD/anxiety and I’ve had a few wobbles this year.
I think you need to respond to her fears with history, science and rational responses.
The climate crisis- yes on the edge of no return but most scientists believe we have time to stop- can she research and read some of the great projects that are showing promise e.g hydrogen power? Countries with progressive climate policies?
Afghanistan- terrible yes. Horrifying, and dreadful for the people that live there, but the history of Afghanistan is long and complex, and there has been tension in the decades. Can she look at some of the ways in which the west are signalling an attempt to open diplomatic channels and humanitarian efforts? Can she look at other geopolitical relationship histories with Afghanistan which are more positive- eg India?
And remind her- the media is a profit making entity. A company. They want clicks and sales- so their headlines and articles are always the most extreme bits of the news. Encourage her to seek out diverse academic perspectives, historians etc. which are generally more measured.
She’ll need your help with this, to talk through her findings, and steer her to more moderate information. But she needs your help anyway.
So much empathy for you both. Good luck. And don’t be afraid to reach out for help from her doctors etc if you feel she needs more medical psychological support.