Scientists lambast The Australian for misleading article on deep ocean cooling
- 28 Jul 2014, 13:50
- Roz Pidcock
An article in Friday's
The Australian suggested brand new research
by two eminent oceanographers casts doubt on scientific
understanding of global warming. But the authors of the research
have taken the newspaper to task for its coverage of their
research by Carl Wunsch from Harvard University
and Patrick Heimbach from MIT found temperatures seem to be falling
in parts of the very deep ocean, known as 'the abyss'.
In a piece headline headlined
"Puzzle of deep ocean cooling",
journalist Graham Lloyd of the Australian interpreted
the new research for readers:
"The deep oceans have
been cooling for the past two decades and [so] it is not possible
to say whether changes in ocean heat adequately explain the "pause"
in global warming".
But the authors think Lloyd's article is
misleading. In an
letter to the editor in today's edition
of the Australian, they say:
article by Graham Lloyd will likely leave a mis-impression with
many of your readers concerning the substance of our
Wunsch tells us Lloyd's article "cherrypicks"
statements from their paper and "misses some key
25th July 2014
Overall, the oceans are warming
new research, just published in the Journal of
Physical Oceanography, explains how measurements in recent decades
suggest some parts of the very deep ocean - the 'abyss' - are
cooling slightly. The paper says:
"[Our findings show]
warming in the abyss at high southern latitudes, in the western
basin of the Atlantic and with cooling elsewhere."
At depths of thousands of meters, taking the
temperature of the deep ocean is very challenging. Quite a lot of
the discussion in the paper is about the limits of current
Though the research suggests some parts of the
very deep ocean are cooling, not all of it is. Scientists can
detect a weak cooling signal overall, but other parts are showing
This wasn't explained by
The Australian, say the authors. Wunsch tell
"If the opening sentence
in the Australian had said 'Parts of the deep ocean have been
cooling for the past two decades' there would have been no quarrel
with that statement."
Wunsch and Heimbach's research is very clear on
an important point - that overall, the planet's oceans are warming.
The letter to the editor says:
"We never assert that
global warming and warming of the oceans are not occurring - we do
find an ocean warming, particularly in the upper
The point the new paper makes is the oceans aren't a solid lump.
Knowing how different parts of the oceans behave is important.
Though new technology is making it easier, the deepest and most
remote parts of the ocean are still poorly understood. Wunsch tells
"[The oceans are] a very
noisy system, with parts warming and parts cooling, it looks like a
net warming is taking place, but exactly by how much is at the very
edge of the science."
Not a reason to doubt scientists explanations
of the "pause"
Lloyd argues that parts of the deep ocean
cooling contradicts other scientists' explanations of the so-called
"pause" in surface warming.
The "pause" describes the fact that temperatures
at earth's surface have risen more slowly in the last 15 years than
in previous decades, despite greenhouse gas emissions continuing to
Scientists say periods of slower and faster
aren't unusual and
the most likely explanation is that heat is making its way to
deep ocean rather than staying at the
The Australian gives the impression Wunsch and
Heimbach disagree with this explanation. It says their study
suggests "much less heat is being added to the oceans than has been
claimed in previous studies".
But that's not the case, say the authors. Wunsch
tells us the overall warming of the ocean they report is consistent
with other scientific literature - a point they also make in the
article by Christopher Booker in Saturday's Telegraph also
argues the new research contradicts other scientists.
US climate professor Kevin Trenberth first described
the slower-than-expected surface warming as the
"missing heat" problem, and has been prominent in research
pointing to faster warming in the deep ocean as a likely
Describing Trenberth as "one of the UN's
top climate alarmists", Booker claims Wunsch's new
paper suggests "the warmists have no real evidence to support
their claim other than computer modelling". He
cold water has been poured on this theory by none other than Prof
Carl Wunsch, probably the world's most respected
letter to the editor makes clear his
findings are of little consequence for global warming or the
so-called "pause". The letter says:
to the implications of Lloyd's article, parts of the deep ocean are
warming, parts are cooling, and although the global abyssal average
is negative, the value is tiny in a global warming
A quote from Dr Andy Hogg of Australia's
National University at the end of the Australian article explains
parts of the very deep ocean can take a very long time
(centuries to millennia) to respond to what's happening at the
"So if cooling has
occurred over large parts of the abyssal ocean, it is unrelated to
global warming of the atmosphere over the last century."
Hogg adds that while there is still
some uncertainty about temperatures in the deep ocean, shallower
regions are well understood and Wunsch's findings are "consistent"
with warming oceans.
Wunsch told us he thought Hogg's comments were
"on the mark," and that it was a shame that they are "hidden at the
end" of the article.