Regarding the possible role hydrogen sulfide
in the major extinctions you might want to check out another book, one which places it
in the context of the
methane clathrate gun, the destruction of the coccolithophores which help to
maintain an oxygenated
atmosphere by ocean acidification, the role of algae blooms, etc...
That's because reorganization likely wouldn't
maintain the same average amount of water vapor
in the
atmosphere (it's the most important «greenhouse gas,» not carbon dioxide or
methane).