I should have added that there is a hypothesis (DeConto et al. 2010) that
orbital forcing triggered the PETM.
Not exact matches
Some workers believe that the strength of the
orbital forcing is too small to
trigger glaciations, but feedback mechanisms like CO2 may explain this mismatch.
Another fascinating question relates to the
triggers for ice ages, which are generally thought to involve reduced summer insolation at 65 N as consequence of
orbital forcing changes.
I have been thinking along these same lines (periodic
orbital and precessional gravitational
forces triggering plate tectonic activity) for over twenty years, although I must say that an effect from sea level variations hadn't occurred to me.
This 800 year lag between temperature and co2 rise only happens as a «
trigger» to end the last ice age, due to
orbital forcing.
Caused by ice formation resulting from a change in heat transport
triggered by meltwater flux at high NH latitude initiated by
orbital forcing; --RRB-