The NASA global
temperature estimate
relies heavily on
estimates of
the temperatures
in the ocean,
and air above it
( over 70% of our planet ).
Ocean temperatures
have been measured
over the years
with inconsistent,
and often haphazard
methods, which have changed
many times over the decades,
from wood buckets off ships;
to canvas buckets off ships,
to cooling water flowing
through ship engine rooms;
to buoys; and since 1979,
by weather satellites.
There are short term
annual ocean cycles
such as the
well-publicized
El Nino / La Nina,
and long term
( multi decade )
cycles, such as the
Pacific ( and Atlantic )
Decadal Oscillations,
which affect ocean
temperatures,
at many depths,
over decades.
Satellite measurements from
the University of Alabama
show atmosphere temperatures
over the ocean increasing since 1980,
but only at +0.13 ° C per decade.
Both major satellite measurement groups
report temperatures are lower now than
they were in 1998, although by different
amounts.
Harvard University oceanographer
Carl Wunsch estimated the
average temperature of the ocean
grew by only +0.02 degrees during
1994 – 2013.
Scripps Institute
of Oceanography
recently estimated
the ocean temperature
growth at only +0.1 ° C
over the last 50 years.
There are many estimates
that ocean temperatures
are not changing much,
at anywhere near the rate
that NASA is claiming.
NASA ignores them.
For government bureaucrats,
more warming is always
better than less warming.
Measurement quality means
nothing to NASA.