David Rose's climate science - half truths and bias
David Rose, writing in the
Mail on Sunday over the weekend, criticised the science behind
the government's decision on carbon budgets, which committed the UK
to halving emissions of carbon dioxide by 2025.
This isn't the first time that Rose has written about climate
piece he wrote for the Mail in December 2010, entitled "What
happened to the 'warmest year on record': The truth is global
warming has halted" was
eviscerated by the Guardian columnist George Monbiot, using
scientific references provided by the Climate Science Rapid Response
With that in mind, we took a look at his claims in last Sunday's
Rose starts by taking issue with both the 2008 Climate Act and
Chris Huhne's statement that cutting emissions of greenhouse gases
would protect the climate, saying:
"Underlying them both is an
assumption that remains widespread - at least in the Westminster
policy-making bubble - that the science of man-made global warming
is 'settled'….Good scientists detest that phrase, pointing out that
science is never 'settled' but rather an ongoing process of
testing, refinement and rethinking."
It is true that the scientific process relies on testing,
refinement and rethinking - this is the process by which
climate science has progressed. Since
Arrhenius first calculated the potential effect of changing CO2
on climate in 1896, the theory has been rigorously tested. A
century of subsequent research has not disproved the theory, and no
plausible hypotheses have been proposed which can account for the
overall warming trend over the past 50 years. There is a
mass of evidence indicating that the globe is warming, with
significant impacts on physical and biological systems around
the world. This is why
97 out of 100 of climate researchers are convinced by
anthropogenic climate change.
Rose goes on to discuss a statement made by Dr Phil Jones of the
University of East Anglia:
"Dr Jones has previously admitted that,
in surprising contrast to what computer models were predicting 20
years ago, there has been 'no statistically significant warming'
Dr Jones agreed in a BBC
interview last year that the warming trend between 1995 and 2009
was "only just" statistically insignificant - a statement which has
was seized upon by climate skeptics (see for example
here, here and
The headlines neglected to mention that in reality, climate
scientists avoid drawing general conclusions about global
temperature trends based on such small amounts of data. As one
put it, considering only 10-15 years of temperature is like
"analysing the temperature observations from 10-17 April to check
whether it really gets warmer during spring."
There has been
roughly 0.75°C warming since the beginning of the 20th Century.
Short-term variations in temperature do
not mean that the warming trend apparent over the last century
has stopped for good. We have written a previous post
discussing this is more detail.
Rose moves on to an exchange with Professor John Mitchell,
principal research fellow at the Met Office:
"I raised this with Mr Mitchell, asking
how long this would have to continue, despite uninterrupted
increases in the level of CO2, before he would start to question
the validity of the models and the theory of man-made warming that
His answer sounded peculiarly
unscientific, implying it would take a lot more than the absence of
actual warming to shake his faith. 'People underestimate the power
of models. Observational evidence is not very useful,' he said.
'Our approach is not entirely empirical.'"
The question that Rose put to Professor Mitchell implies that
scientists do not question the validity of the models that they use
and their underpinning theories. In reality, climate scientists are
constantly questioning, refining and improving models. The IPCC AR4
report devotes an
entire section to that very topic.
It is obvious that models that are attempting to construct what
may happen tomorrow cannot rely solely on observations of what is
happening today. Scientists instead rely on
sensitivity studies or comparing
outcomes from many different models.
Rose moves on to the skeptics:
"Others at the conference presented
powerful opposing arguments. Ian Plimer, professor of geology at
Adelaide University in Australia, showed how the world was often
much warmer before industrialisation. He added that only three per
cent of the CO2 in the atmosphere comes from human activity, the
rest originating from sources such as volcanos."
The argument that "the climate has warmed in the past, therefore
the current warming cannot be man-made" has been described in a recent
book as "….akin to saying 'forest fires have occurred naturally
in the past so any current forest fires must be natural'."
The natural processes controlling climate in the past are
insufficient to explain the warming trend over the 20th
century. Similarly, the argument that only 3% of the C02 in the
atmosphere comes from human activity ignores the fact that man-made
emissions of C02 are
additional to the natural carbon cycle. As a result of man's
activities atmospheric CO2 is now at the highest
level for 15 to 20 million years.
Plimer's claim (also made
elsewhere) that most of the carbon dioxide in the air is a
result of volcanos is totally unfounded. The US
Geological Survey (USGS) has assessed the scientific literature
regarding CO2 emissions and finds that CO2 emissions resulting from
human activity are around 100 times higher than CO2 emissions
resulting from volcanos.
Rose continues by citing work from Professor Henrik Svensmark,
who argues that
"…one of the key determinants of climate
is the level of cosmic rays from outer space that hit the Earth:
these high-energy particles 'seed' the clouds by forming what he
termed 'ultra-fine condensation nucleii'. More rays mean more
clouds, and in turn, a cooler climate.
"According to Prof Svensmark, quite
small variations in the amount of cloud cover have a big effect on
temperature, leaving man-made CO2 emissions with a small 'residual'
The theory that cosmic rays influence cloud cover has been under
discussion since Svensmark first suggested it in 1996. A
review of the evidence published in March concluded that:
"No correlation is found between
cosmic ray changes and the whole cloud cover…Cosmic rays have
negligible effect on the global temperature and on
Rose goes on to discuss a
report recently written for the GWPF by Lord Turnbull:
"Lord Turnbull…warned that the 'real
inconvenient truth' of UK climate policy is not that described by
Al Gore's alarmist film, but the fact that the 'whole structure is
built on shaky foundations'…
We have addressed the five key scientific errors in Lord
Turnbull's report in a
"He identifies some of the warmists'
bigger difficulties, such as having to explain why there have been
several periods since the Industrial Revolution started when
temperatures have declined."
As outlined above, the fact that temperature has gone up and
down over the last 150 years does not disprove the overall warming
"Another is that even if CO2 were
to double, even the most gloomy warmists agree that this alone
would cause a temperature rise of just one degree - a far cry from
the three to six degrees posited by their models.
"To justify this, they claim small
increases in CO2 will trigger amplifying 'positive feedback' - a
rise in atmospheric water vapour and a more effective 'greenhouse
gas' than carbon dioxide. But is this true? Citing unimpeachable
scientific sources, Lord Turnbull says it is 'assumed, but
In response to the last point, climate scientists assess a
measure known as 'climate sensitivity' - how much the world would
warm if the amount of carbon dioxide in the atmosphere doubled. The
estimates that climate sensitivity is between 2 and 4.5 ˚C.
The amplifying effect of water vapour was predicted by climate
models and has been experimentally
confirmed. There have been suggestions that warming will
increase low-level cloud cover, and that this will provide a
cooling feedback, regulating climate change. However, a number of
recent studies indicate that even low-lying clouds are more
likely to cause warming, and any cooling effect from clouds is
to offset the water vapour amplification and other warming
The "unimpeachable scientific sources" referred to appears to be
a sentence in the GWPF report:
"Some scientists such as Professor
Lindzen of MIT argue that the net [feedback] effect [of water
vapour] could go either way."
However this statement is not referenced, so it is not clear to
what research he is referring.
Overall, Rose's article is a collection of biased half-truths
and unreferenced statements. Many of these have been repeated
elsewhere many times by climate skeptics - and the overall effect
is to give an entirely misleading picture about the current state
of climate science.