I am looking for examples of authors who manage to have sarcastic/funny characters exist in a very serious, end of the world type of scenario.
The issue I am trying to resolve is when I write character dialogue several are quite sarcastic, and rarely serious but find themselves in dire situations...how do I balance the levity and the plot line without detracting from the seriousness of the situation?
One method I have seen was where a character was constantly making smart remarks (many of which were very funny), In scenes where the author wanted a more serious tone, the jokes told were not as funny, as if the character was trying to break the tension, and not doing a very good job.
Another method is to have a running joke that is more sad or touching at a climatic scene. this is often seen where a character jokes about being a hero while acting cowardly until the climax, where he lays aside the cowardice and saves the day.
I'm thinking of Inigo Montoya in "The Princess Bride." It's funny in a sad way how he fixates on wanting to say, "Allo. My name is...[etc]." Then in the castle fight it's pretty funny. And finally his "punch line" to his "joke" at the end. That was powerful, because there was humor, hatred, rage, helplessness, and vengeance all mixed up. You cheered for him, high-fived him for the cleverness, and yet mourned with him that satisfying his vengeance still left him empty -- he could never have his father back.
My point: Jokes don't always have to be "haha" funny to be effective. In fact, during the worst times, the crisis moments, they really shouldn't be "haha" funny. At that point, re-use an often-repeated joke -- only now it's not funny.
You could also study "Stargate SG1." That's a TV show, not a book, but Jack's character is, IMHO, a great example of what you're talking about.
Why is it an issue? Don't you know anyone with a black sense of humor? People crack jokes, particularly sarcastic ones, in the darkest of hours. I wouldn't find it problematic, particularly if you've established that the sarcastic character is a wiseass who uses humor to deflect or to ratchet down emotionally intense situations as a character trait.
I'd read true-life cop stories or military memoirs for something like this. First responders develop "gallows humor" to help cope with the stress of the job. Try the BBC documentary series Inside Afghanistan.
I think one of the best examples is Jaroslav Hašek's masterpiece The Good Soldier Švejk.
The novel is set during World War I in Austria-Hungary, a multi-ethnic empire full of long-standing tensions. Fifteen million people died in the War, one million of them Austro-Hungarian soldiers of whom around 140,000 were Czechs. Jaroslav Hašek participated in this conflict and examined it in The Good Soldier Švejk. [..] The character of Josef Švejk is a development of this theme. Through possibly-feigned idiocy or incompetence he repeatedly manages to frustrate military authority and expose its stupidity in a form of passive resistance: the reader is left unclear, however, as to whether Švejk is genuinely incompetent, or acting quite deliberately with dumb insolence. These absurd events reach a climax when Švejk, wearing a Russian uniform, is mistakenly taken prisoner by his own troops.
