[na na (OP)]

How much methane do biological organisms output globally, and what percentage of these methane emissions can be attributed to global warming? ("biological organisms" includes methane producing plants, bacteria (methanogens) and animals)

Many thanks

[MOD - subject edited to make question clear - CS]

[na na (OP)]

Addendum: this should also include landfill etc.; though I suspect that methane emissions from landfill and the like is produced by bacteria.