However, short term studies can not take into account long term feedbacks such as ice albedo changes and CH4 and CO2 releases from soil and ocean. (judithcurry.com)
Basically per the work of Zeebe and others, the idea is that in those times (and today) the rates of CO2 emissions, and temperature increases, overwhelmed the short term feedbacks (biosphere, surface ocean etc), before the long term feedbacks (deep ocean, weathering, etc) could cut in to process them. (skepticalscience.com)
Most models do not consider the possibility that long term feedbacks (Hansen et al., 2007; Knutti and Hegerl, 2008) may be different (see Section 12.5.3). (climateaudit.org)