Rupert Darwall - An Unsettling Climate
Rupert Darwall - An Unsettling Climate
Rupert Darwall - An Unsettling Climate
Rupert Darwall
C
limate-change science is settled, say proponents of an-
thropogenic (human-induced) global warming, or AGW:
the earth is getting warmer, and human activities are the
reason. The Intergovernmental Panel on Climate Change
(IPCC), set up by the United Nations in 1988, has issued
five assessment reports since its founding. In its most re-
cent, in 2013, the IPCC stated that it was now 95 to 100
percent certain that human activitiesespecially fossil-fuel emissionsare
the primary drivers of planetary warming. Frequent news reportssuch as
the story of the melting of the West Antarctic Ice Sheet, a process that some
scientists say is irreversibleseemingly confirm these conclusions.
And yet, highly credentialed scientists, including Nobel Prizewinning
physicist Ivar Giaever, reject what is often called the climate consensus.
An Unsettling Climate
Global-warming
proponents betray
science by shutting
down debate.
Human activities account for less than 5 percent of the carbon emissions
released into the atmosphere.
P
A
U
L
S
O
U
D
E
R
S
/
C
O
R
B
I
S
CITY JOURNAL 96
An Unsettling Climate
worlds economyan effort that would have
major effects on economic growth and quality
of life, especially in the developing worldwas
not justified by observable scientific evidence.
And, like Giaever, they objected to the notion
of a climate consensusand to the unscientific
shutting down of inquiry and the marginaliza-
tion of dissenters as heretics. Most recently,
Giaever resigned from the American Physical
Society in protest of the groups statement that
evidence of global warming was incontrovert-
ible and that governments needed to move im-
mediately to curb greenhouse-gas emissions.
Sixteen distinguished scientists signed a 2012
Wall Street Journal article, in which they argued
that taking drastic action to decarbonize the
Scientist Murry Salby argues that a key factor behind rising temperatures is heat exchange between the
atmosphere and the ocean.
SUMMER 2014 97
NSF investigated the disappearance of $100,000
in Salbys research funds, which, in the wake of
the investigation, was returned to Salbys group.
However, all these matters have involved bu-
reaucratic rights and wrongs. They have no bear-
ing on his science, just as Antoine Lavoisiers
being a tax farmer had no bearing on his demoli-
tion of the phlogiston theory of combustion. And
Salby had earned high marks as a scientist. He
originally trained as an aerospace engineer before
switching to atmospheric physics and building a
distinguished career. He taught at Georgia Tech,
Princeton, Hebrew,
and Stockholm Uni-
versities before com-
ing to the University
of Colorado, and he
was involved as a re-
viewer in the IPCCs
first two assessment
reports.
Starting in the late
1990s, Salby began a
project to analyze changes in atmospheric ozone.
His research found evidence of systematic re-
covery in ozone, validating the science behind
the 1987 Montreal Protocol, which introduced
specific steps for curtailing ozone-depleting
gases. Preparing to write a graduate-level text-
book, Physics of the Atmosphere and Climate,
later published by Cambridge University Press
and praised by one reviewer as unequalled in
breadth, depth and lucidity, Salby then under-
took a methodical examination of AGW. What he
found left him absolutely surprised.
Most discussion on the science of AGW re-
volves around the climatic effects of increased lev-
els of carbon dioxide in the atmosphere. How it
got there in the first placethe assumption being
that increased carbon dioxide arises overwhelm-
ingly from human activitiesis often taken for
granted. Yet Salby believed that he had uncovered
clear evidence that this was not the case, as his trip
to Europe was designed to expose.
The IPCC estimates that, since the Industrial
Revolution, humans have released 365 billion
tons of carbon from burning fossil fuels. Annual
renowned climate scientist Lennart Bengtsson
stepped down from his post at a climate-skeptic
think tank after he received hundreds of angry
e-mails from scientists. He called the pressure
virtually unbearable.
Another dissenter, the American atmospheric
physicist Murry Salby, has produced a serious
analysis that undermines key assumptions un-
derpinning the AGW worldview. His work and
its reception illustrate just how unsettled climate
science remainsand how determined AGW
proponents are to enforce consensus on one of
the great questions of
our age.
In April 2013, con-
cluding a European
tour to present his re-
search, Salby arrived
at Charles de Gaulle
Airport in Paris for a
flight back to Austra-
lia, where he was a professor of climate science
at Macquarie University. He discovered, to his
dismay, that the university had canceled the re-
turn leg of his nonrefundable ticket. With Salby
stranded, Macquarie then undertook misconduct
proceedings against him that swiftly culminated
in his dismissal. The university claimed that it did
not sack Salby for his climate views but rather be-
cause he failed to fulfill his academic obligations,
including the obligation to teach and because he
violated University policies in relation to travel
and use of University resources.
Salby and his supporters find it hard to believe
the schools claims. Salbys detractors point to
reports of his investigation by the National Sci-
ence Foundation (NSF) for alleged ethical im-
proprieties, claims surrounding which surfaced
on an anti-climate-skeptic blog, along with court
papers relating to his divorce. Salby has indeed
been embroiled in conflicts with the NSFthe or-
ganization debarred him from receiving research
grants for three years, even though, teaching in
Australia, he wasnt eligible, anywayand with
the University of Colorado, where he taught pre-
viously and was involved in a decade-long dis-
pute with another academic. At one point, the
Murry Salbys
work and its reception
illustrate just how
unsettled climate science
remains.
E
D
W
A
R
D
F
R
A
Z
E
R
/
C
O
R
B
I
S
CITY JOURNAL 98
An Unsettling Climate
report, in 2007: The increase in
atmospheric CO
2
is known to
be caused by human activities.
Salby contends that the
IPCCs claim isnt supported
by observations. Scientists
understanding of the complex
climate dynamics is undevel-
oped, not least because the
oceans heat capacity is a thou-
sand times greater than that of
the atmosphere and relevant
physical observations of the
oceans are so sparse. Until this
is remedied, the science can-
not be settled. In Salbys view,
the evidence actually suggests
that the causality underly-
ing AGW should be reversed.
Rather than increased levels
of CO
2
in the atmosphere trig-
gering global temperatures to
rise, rising global temperatures
come firstand account for the
great majority of changes in net
emissions of CO
2
, with changes
in soil-moisture conditions ex-
plaining most of the rest. Fur-
thermore, these two factors also
explain changes in net methane
emission, the second-most important human
greenhouse gas. As for what causes global tem-
peratures to rise, Salby says that one of the most
important factors influencing temperature is
heat exchange between the atmosphere and the
ocean.
Why is the IPCC so certain that the 5 percent
human contribution is responsible for annual
increases in carbon dioxide levels? Without ex-
amining other possible hypotheses, the IPCC ar-
gues that the proportion of heavy to light carbon
atoms in the atmosphere has changed in a way
that can be attributed to addition of fossil fuel car-
bonwith light carbon on the rise. Fossil fuels, of
course, were formed from plants and animals that
lived hundreds of millions of years ago; the IPCC
reasons that, since plants tend to absorb more light
carbon than heavy carbon, CO
2
emissions from
burning fossil fuels reduce the share of heavy
emissions, including those from deforestation
and cement production, are less than 9 billion
tons. Yet natural carbon cycles involve annual
exchanges of carbon between the atmosphere,
the land, and the oceans many times greater
than emissions from human activities. The IPCC
estimates that 118.7 billion tons of carbon per
year is emitted from land and 78.4 billion tons
from oceans. Thus, the human contribution of
9 billion tons annually accounts for less than 5
percent of the total gross emissions. The AGW
hypothesis, as well as all the climate-change
policies that depend on it, assumes that the hu-
man 5 percent drives the overall change in the
amount of CO
2
in the atmosphereand that the
other 95 percent, comprising natural emissions,
is counterbalanced by absorption of CO
2
from
the atmosphere by natural processes. Summing
it up, the IPCC declared in its fourth assessment
SUMMER 2014 99
Unable to explain natural changes in CO
2
emission, the IPCC falls back on its assumption
of a strong natural tendency toward equilibrium:
over time, natural emissions and absorption bal-
ance each other out, leaving mankind respon-
sible for disruptions in the balance of nature.
But, as Salby observes, the IPCC merely postu-
lates this tendency without demonstrating it.
The IPCCs confidence in attributing warming to
human activities is thus highly questionable
especially since, for the last decade and a half, at-
mospheric temperatures have not risen, even as
CO
2
has risen steadily.
Further, while ob-
served average global
temperature rose just
under one degree cen-
tigrade in the last cen-
tury, this didnt occur
as a steady warming.
Almost the entire
twentieth-century rise
came from four de-
cadesa portion of the interwar years and the
1980s and 1990sless than a third of the overall
temperature record.
Were it not for its implications for AGW,
Salbys research on the carbon cycle might be
a boon to the IPCCs troubled effort to explain
interannual variability of CO
2
emissions. His
work offers a coherent picture of changes in
net emissions, where the changes closely track
a combination of temperature and soil mois-
tureexplaining both the low net emissions of
the early 1990s and their peak in 1998. Salby also
contends that temperature alone can largely ac-
count for the rise in atmospheric CO
2
through
the earlier part of the twentieth century, when
soil-moisture data are inadequate. Net methane
emissions track natural surface conditions even
more closely.
Another pillar of the IPCCs case has been the
claim, based on ice-core records of CO
2
concen-
trations, that present levels of carbon dioxide
are unprecedented. But here, Salby maintains,
accounting for the dissipation of CO
2
trapped
in ice corespreviously ignoredradically
alters the picture of prehistoric changes in at-
mospheric CO
2
levels. Even weak dissipation
carbon in the atmosphere. But Salby points to
much larger natural processes, such as emissions
from decaying vegetation, that also reduce the
proportion of heavy carbon. Temperature heavily
influences the rate of microbial activity inherent
in these natural processes, and Salby notes that
the share of heavy carbon emissions falls when-
ever temperatures are warm. Once again, temper-
ature appears more likely to be the cause, rather
than the effect, of observed atmospheric changes.
Further, Salby presents satellite observations
showing that the highest levels of CO
2
are pres-
ent not over indus-
trialized regions but
over relatively un-
inhabited and non-
industrialized areas,
such as the Amazon.
And if human emis-
sions were behind ris-
ing levels of CO
2
in
the atmosphere, he ar-
gues, then the change
in CO
2
each year should track the carbon dioxide
released that year from burning fossil fuels
with natural emissions of CO
2
being canceled
out by reabsorption from land sinks and oceans.
But the change of CO
2
each year doesnt track the
annual emission of CO
2
from burning fossil fu-
els, as shown in Figure 1, which charts annual
emissions of CO
2
, where an annual increase of
one part per million is approximately equivalent
to an annual growth rate of 0.25 percent.
While there was a 30 percent increase in CO
2
fossil-fuel emissions from 1972 to 1993, there was
no systematic increase in net annual CO
2
emis-
sionthat is, natural plus human emissions, less
reabsorption in carbon sinks. These data, Salby
observes, are inconsistent with the IPCCs claim
to certainty about human causation of rising CO
2
levels in the atmosphere. For the better part of
two decades, the IPCC has been struggling to ex-
plain the wide interannual variability of changes
in net CO
2
emission (the jagged lower line in
Fig. 1). Various causes have been suggested to
explain the 1990s slowdown of CO
2
growth, but
none fully explains this unusual behavior of the
carbon cycle, as the IPCC conceded in its third
assessment report.