Her voice shakes.
You sense her very foundation has been shaken.
This isn't an actor, a newscaster, or a spokesperson. She hasn't planned her words. She doesn't know what she's going to do next, only knows she has to act. She uses the word "bullshit," and then apologizes.
The anger in her voice seems directed mainly at herself. She'd persuaded "every person [she] know[s]" not to believe in the reality of global warming. Now she has to change their minds.
Full transcript after the little orange cumulus. Because in this case, partial just won't do.