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Willie Soon, David R. Legates, & Christopher Monckton of
Brenchley12 Feb 2016394
How much will the doubling of CO2 in the air warm the global
temperature? How do scientists take an accurate measurement of the
temperature of the Earth’s atmosphere? Why can scientists better
measure atmospheric temperatures from satellites than surface
temperatures from ground thermometers?

Despite large uncertainties and many unknowns in Earth Science,
scientists have a reasonable understanding of the answers to these
questions.

Atmospheric CO2 is a “greenhouse gas,” and therefore, an increase
of its concentration in the atmosphere will tend to warm the air.
But the latest scientific research by William Happer of Princeton
University has shown that the belief that a doubling of atmospheric
CO2 will cause directly a 1°C warming of the globe may be
incorrect. Indeed, the more likely answer is that a doubling of CO2
will cause only a 0.6°C warming, or about 40% less than previously
thought. This makes it even more important to take with caution the
excessive impact of CO2 on global air temperatures.

Complicating our understanding is that many processes involving the
atmosphere, the ocean, and the land surface which affect the
warming effect of CO2 are highly complex and largely incompletely
understood. Those rushing to transition from a fossil fuel-based
world economy to the wickedly named “decarbonized” future tout a
relationship between a doubling of CO2 and global temperatures as
large as 4 to 5°C. But how can such a calculation have any basis in
scientific fact when the processes that form clouds, rainfall,
snow, and ice — as well as the flow of air and ocean currents — are
so imprecisely understood? How is it possible to create an accurate
climate model given such uncertainties?

So, how well can we measure the consequences of CO2 on global air
temperatures? Even this simple question is marred with half-truths
and distortions arising from the politics of global climate
change.

It is universally accepted that the most direct impact of
atmospheric CO2 will be the warming of the lowest six miles of air.
This is the layer that is best measured by satellites and
balloon-borne instruments rather than surface-based thermometers
which under-represent the poles, the tropics, the high altitudes,
and the oceans. In short, thermometers are biased to where people
live and confined to measure only the air within six feet of the
ground. Satellites, by contrast, are not limited spatially and can
estimate global temperatures in the lowest six miles, not six feet,
of air.

But of late, anthropogenic climate change “believers” are pushing
thermometer-based analyses and dismissing satellite observations.
Why? For nearly the last two decades, satellite- and balloon-borne
instruments have not detected any significant warming which does
not support the climate change “disaster” scenarios the believers
wish to promote. Besides, the bias associated with surface
thermometers can easily be manipulated with subjective “bias
adjustments” which allows the data to support the global warming
hype.

A recent paper published in Earth Science Reviews (by W. Soon, R.
Connolly and M. Connolly) discusses and demonstrates that the
post-1970 warming, as measured by surface-based thermometers, was
highly exaggerated by non-climate related factors such as changes
in location, the time-of-observation bias, urbanization effects,
and changes in land use as well as by changes in the measurement of
sea-surface temperature and the fair-weather bias (ships tend to
avoid storms) to estimate air temperature over the oceans.

However, the most important problem with thermometer/surface-based
assessments is that the most important signal arising from CO2
impacts lies higher in troposphere — at about six miles — rather
than at the surface. Satellite observations have provided a nearly
complete global coverage since about 1979, providing us with an
excellent record extending more than 35 years. These observations
indicate that the atmosphere warmed slightly since 1979 but its
temperature has remained relatively constant over the past fifteen
years or so — despite the dramatic increase in CO2 concentrations. 
This makes it hard to argue that global temperature changes are
largely driven by changes in atmospheric CO2 concentrations.

Scientists from the National Oceanic and Atmospheric Administration
(NOAA) cling to their bias-adjusted surface temperature record
because it yields a far more continuous and rapid rate of warming
than what was deduced from satellites and weather balloons records.
This is consistent with the exaggerated “CO2 disastrously warms the
planet” meme that, in part, keeps their funding levels high.
Recently, they released a newer version that exaggerates the
warming even further. Detailed explanations for their revisions —
published in Science in June of 2015 — are not convincing but it is
clear that their main effort was focused on making sure that the
pause in air temperature increases over the past two decades
vanished. The editor-in-chief of Science magazine, Dr. Marcia
McNutt, proclaimed at a climate symposium in January that the
revision “eliminates the [global warming] hiatus.” Scientists from
NOAA and Lawrence Berkeley National Laboratory also wrote in
Science that “whether or not the early 21st century global warming
hiatus existed is not important”.

It is appropriate for us to offer a reminder from our colleague,
the late Professor Bob Carter, who as early as 2006 warned that
“There IS [sic.] a problem with global warming… it stopped in 1998…
In truth, however, the biggest part of the problem is neither
environmental nor scientific, but a self-created political
fiasco.”

From a physics standpoint, the impact of increasing CO2 causes a
relatively and disproportionately larger warming in the atmosphere
than near the ground. Is there a problem, therefore, with the
satellite record or the way in which it measures air temperature?

As previously mentioned and usually ignored by the believers,
thermometers provide a poor spatial coverage of the Earth’s
surface. By contrast, satellites carry instruments that accurately
measure the amount of energy in thermal infrared and microwave
wavelengths which directly relates to the temperature of the lower
atmosphere (where most of the air resides and where the CO2 signal
should be strongest) with nearly complete spatial coverage.

Global estimates of air temperature by satellites are independently
produced by scientists from Remote Sensing Systems (RSS) and the
University of Alabama-Huntsville (UAH), and their methods have been
well-discussed and compared in the scientific literature.  Both
groups show that global temperatures in the lowest six miles show
no warming trend since 2002 (we start in 2002 mainly because the
new global atmospheric temperature data record [labeled ROM SAF in
the top panel] is available only starting September 2001 and partly
to avoid the effect of the strong El Nino and La Nina between 1997
and 2001 – see graph below).

chart

The big complaint leveled against the satellite record is that
their estimates are contaminated by the decay of satellite orbits,
changes in the satellite orientation over time, and the piecing
together of several satellites to complete the record since 1979.
While these issues allow for more physically-based adjustments than
with the thermometer record (note that new satellites overlap with
older ones and that satellite orbital decay is well-documented),
the balloon data corroborate the satellite record.

In addition, a third method of measuring global temperature over
the lower atmosphere — using the series of GPS (Global Positioning
System) satellites — can be obtained by accurately by measuring the
propagation of radio waves through the atmosphere. The importance
of this new method is that a near-complete coverage of the Earth is
afforded and that global atmospheric temperature can be determined
without requiring any complex satellite inter-calibration. Only the
precise atomic clock is needed to measure the relative delay in
propagation of radio waves through the atmosphere which, in turn,
allows for a direct assessment of the atmospheric temperature over
the lower portion of the atmosphere.

Unsurprisingly, the GPS-based method confirms what was measured by
the thermal infrared/microwave radiometers aboard other satellites;
that the nearly-two-decade-long temperature hiatus is real and the
thermometer-based record is the oddball. More specifically, global
atmospheric temperatures are not warming in the way predicted by
the CO2-driven climate models, which serves to argue that CO2 does
not act as the thermostat for global atmospheric temperatures.

An objectively science-based decision is clear: The preponderance
of the evidence suggests that a discernable CO2-influence on the
climate has been grossly overstated. So will you choose the
scientific decision or rely on the politically-driven thermometer
adjustments? Our future rides on the answer to this question.