Abstract
Paleo and recent sea surface temperature (SST) measurements at six
locations spanning the North Atlantic, from the northeastern North
Atlantic off the British Isles to the Dry Tortugas in the southwest,
were examined in order to determine whether a period of cooling was
responsible for the die-off of elkhorn corals (Acropora palmata) on the
reef off Broward County around six thousand years ago (6 Kya) and
whether warming sea temperatures might contribute to their recovery. The
paleo data show indications of a warm period between 13 Kya and 7 Kya,
followed by cooling, probably due to orbital forcing arising from the
coincidence of insolation maxima in the Milankovitch obliquity and axial
precession cycles in the Northern hemisphere at that time, but the lack
of paleo data in the immediate proximity of the reef makes it difficult
to draw firm conclusions regarding the die-off of the corals. However,
the marine SST data obtained from ships and buoys since 1870 raise
questions about the presumed recent global warming. Annual average sea
surface temperatures in the North Atlantic show remarkable stability and
consistency with little or no change over the 146 years between 1870 and
2015, despite large seasonal and latitudinal variation in response to
differences in solar irradiance.