Abstract. The Mid-Brunhes Transition (MBT) began ∼ 430 ka with an increase in
the amplitude of the 100 kyr climate cycles of the past 800 000 years. The
MBT has been identified in ice-core records, which indicate interglaciations
became warmer with higher atmospheric CO2 levels after the MBT, and
benthic oxygen isotope (δ18O) records, which suggest that
post-MBT interglaciations had higher sea levels and warmer temperatures than
pre-MBT interglaciations. It remains unclear, however, whether the MBT was a
globally synchronous phenomenon that included other components of the climate
system. Here, we further characterize changes in the climate system across
the MBT through statistical analyses of ice-core and δ18O
records as well as sea-surface temperature, benthic carbon isotope, and dust
accumulation records. Our results demonstrate that the MBT was a global event
with a significant increase in climate variance in most components of the
climate system assessed here. However, our results indicate that the onset of
high-amplitude variability in temperature, atmospheric CO2, and sea
level at ∼430 ka was preceded by changes in the carbon cycle, ice
sheets, and monsoon strength during Marine Isotope Stage (MIS) 14 and MIS 13.
Supporting evidence from the EPICA Dronning Maud Land ice core for atmospheric CO2 changes during the past millennium