Climate scientists around the globe last week proclaimed 2016 the hottest year on record, but a closer look at the underlying data splashes some cold water on the latest global warming numbers.
scientists say recent temperature measurements are either statistically
insignificant or the result of cyclical factors that will "even out"
An overall warming trend does seem clear, but
interpretations of it vary. Current data on land and surface
temperatures worldwide point to an overall trend toward planetary
warming since the mid-20th century, according to scientists at NASA and the National Oceanic and Atmospheric Administration.
at NASA’s Goddard Institute for Space Studies (GISS) found that
globally averaged temperatures last year were 0.99 degree Celsius, or
1.78 degrees Fahrenheit, above a mid-20th century baseline or
average. The numbers mean that 2016 was the hottest year ever since
regular temperature record-keeping began in 1880, the agency said.
United Kingdom’s national meteorological service, Met Office, also
agreed with 2016 being the hottest year, based on a separate analysis.
who take a less sizzling view of 2016, however, tend to emphasize
year-to-year changes rather than what are known as temperature anomalies
– the difference between a selected year’s average global temperature
and an average of temperature readings spanning many decades.
Met Office numbers found that the 2016 average temperature was only 0.77
degree Celsius above an average for the years 1961 to 1990, but the
meteorological service also reported that 2015 came in at 0.76 degree
Celsius above the baseline average. So the difference between the two
years is only 0.01 degree Celsius, which is far under the calculated
error rate of 0.1 degree Celsius.
And there’s a similar
insignificance between Met Office’s numbers for 2014 and 2013 – 0.07
degree Celsius, which again is well within the study’s margin of error.
Still, such year-to-year analyses are less important for NASA scientists than what they see as evidence of long-term trends.
climate studies, what matters are not the year-to-year fluctuations
that are often impacted by unpredictable volcanic eruptions or ENSO (El
Nino Southern Oscillations), but the long-term trends,” Reto Ruedy, a
project manager at GISS, told AMI Newswire. “To measure and present
those, you need a fixed base to which individual years can be compared.”
figures from NOAA seem to mirror the Met Office numbers for recent
years. The difference between 2016 and 2015 is only 0.04 degree Celsius
– again, a fraction of the margin of error of 0.1 degree Celsius. Such
figures seem to add doubt to whether 2016 is truly the hottest year on
record since the difference in the average global temperatures is
GISS’s analysis of global
temperatures uses a baseline average of global temperatures recorded
from 1951 to 1980. The NASA study found that 2016 was 0.12 degree
Celsius warmer than 2015 and that 2015 was 0.13 degree Celsius warmer
than 2014. These figures do surpass the 0.1 degree rate of error, but
only by a relatively small amount.
And 2014 was found to be only 0.09 degree Celsius hotter than 2013 – a figure that’s, again, dwarfed by the error rate.
addition, NASA officials concluded that the El Nino effect in 2016
boosted average global temperatures by 0.12 degree Celsius. That is the
exact difference between the 2016 global average temperature and the
2015 number, as Dr. David Whitehouse of the Global Warming Policy Forum
pointed out in a recent blog post.
So if you factor in El Nino, 2016 doesn’t look so piping hot, Whitehouse concluded.
not so fast, says NASA’s Ruedy, who has studied past El Nino years.
“2016 is also a record year in an adjusted time series from which the
effects of volcanoes and ENSOs have been removed,” he said.
difference between NASA’s temperature numbers and those of NOAA and Met
Office is that the latter two agencies provide surface temperatures only
for areas where they have hard data, whereas GISS extrapolates its
numbers to a larger domain – the Arctic in particular, according to
Ruedy. Arctic temperatures in 2016 were much higher than usual, causing
GISS’s numbers to differ more than usual with the other two agencies, he
Others see this sniping over data sets as missing the bigger picture.
can’t resolve whether 2016 was the hottest year with the instruments we
have,” James Taylor, president of a policy institute called the Spark
of Freedom Foundation, told AMI.
Humans are causing some warming on the planet, Taylor said, but he doesn’t think it’s as serious a problem as others do.
more on nuclear power, natural gas and hydroelectric power is a
common-sense option that those on the left and right could embrace to
deal with perceived climate change issues, he said.
“If we are
concerned about global warming, there are options available to reduce
carbon dioxide emissions that make economic sense and would be supported
by most skeptics and most conservatives,” Taylor said.
criticized how government scientists make adjustments to global
temperature data, ostensibly to eliminate non-climatic factors such as
equipment updates at weather stations.
“One takeaway from the
(2016) temperature dispute is the need for a global network of surface
temperature stations that don’t need to be adjusted by government
officials, who often have an interest in viewing temperature one way or
another,” Taylor said.
NASA scientists, however, remain cool to
the skeptics’ arguments. “2016 is remarkably the third record year in a
row in this series,” GISS Director Gavin Schmidt said in a prepared
statement. “We don’t expect record years every year, but the ongoing
long-term warming trend is clear.”