While El Niño played a role in bumping up global temperatures
during 2015 and 2016, the bulk of the warmth was due to the excess heat trapped by greenhouse gases emitted by humans over the
past century,
particularly carbon dioxide.
During the
past century land use change has given rise to regional changes in the local surface climatology,
particularly the mean and variability of near surface temperature (Pitman et al, 2012).