A global land–ocean temperature record has been created
by combining the Berkeley Earth monthly land temperature field with
spatially kriged version of the HadSST3 dataset. This combined product spans
the period from 1850 to present and covers the majority of the Earth's
surface: approximately 57 % in 1850, 75 % in 1880, 95 % in 1960, and
99.9 % by 2015. It includes average temperatures in 1∘×1∘ lat–long grid cells for each month when available. It provides
a global mean temperature record quite similar to records from Hadley's
HadCRUT4, NASA's GISTEMP, NOAA's GlobalTemp, and Cowtan and Way and
provides a spatially complete and homogeneous temperature field. Two
versions of the record are provided, treating areas with sea ice cover as
either air temperature over sea ice or sea surface temperature under sea
ice, the former being preferred for most applications. The choice of how to
assess the temperature of areas with sea ice coverage has a notable impact
on global anomalies over past decades due to rapid warming of air
temperatures in the Arctic. Accounting for rapid warming of Arctic air
suggests ∼ 0.1 ∘C additional global-average
temperature rise since the 19th century than temperature series that do
not capture the changes in the Arctic. Updated versions of this dataset will
be presented each month at the Berkeley Earth website
(http://berkeleyearth.org/data/, last access: November 2020), and a convenience copy of the version
discussed in this paper has been archived and is freely available at
https://doi.org/10.5281/zenodo.3634713 (Rohde and Hausfather,
2020)....

The Berkeley Earth Land/Ocean Temperature Record

10.5194/essd-12-3469-2020