At the age of 92 Sir David Attenborough finds himself an Emmy nominee, in the category of Outstanding Narrator. But he's not the oldest contender in the field. That honor falls to 96-year-old Carl Reiner, recognized for his work on the documentary If You're Not in the Obit, Eat Breakfast. Attenborough's nomination—the fourth of his career—comes for his narratorial efforts on the BBC America documentary series Blue Planet II, a vibrant exploration of the abundant life…