Has Earth grown larger from the buildup of decaying vegetation through the ages?

— Robert in Spartanburg, S.C.

Earth isn’t getting bigger. It’s actually getting smaller!

Decaying vegetation does pile up across the planet, but not everywhere equally. Wind and rain erode the ground over time, and even where leaves and other vegetation do gradually accumulate, like peat bogs and river deltas, that material doesn’t add to Earth’s bulk.