Sentences with phrase «biological feedback cycles»

Along with my colleagues Dave Johnston and Ann Pearson at Harvard and NASA's Felisa Wolfe - Simon, I hypothesize that biological feedback cycles, including one involving sulfide - based photosynthesis, would tend to maintain this world in which oxygen levels remain low and sulfide high [for the next «boring» billion years].

Not exact matches

Hence, carbon - cycle feedbacks linked to biological activity appear to have played at least some role in the climate variations of the past thousand years.

However, some carbon cycle feedbacks are either poorly represented or omitted from climate models because of uncertainties in their underlying biological and geological processes.