From the paper: «The results also 1) reveal a significant level of coupling between ocean and
land temperatures that remains even
after the effects of ENSO and
volcanic eruptions have been removed; 2) serve to highlight the improvements in the quality of the time series of global - mean
land temperatures with the increase in the areal coverage of the station network from 1951 onward; and 3) yield a residual time series in which the signature of anthropogenically induced global warming is more prominent.»