Harry Chickpea wrote:

....
Oddly enough, there may be a non-human culprit that bears some
responsibility for increasing carbon levels. I was surprised to find
that the common earthworm is not indiginous to north america, but was
imported by the europeans. While earthworms do aerate the soil, they
are also implicated in shinking the layers of detrius called "duff"
that carpets forest lands. That duff is a huge carbon sink that is
being lost.

Reference?