Christopher Booker on climate science: comment and conjecture, but where are the facts?
- 21 May 2012, 15:15
- Verity Payne
Another Monday, another
article from Christopher Booker containing some choice snippets
of misleading information on climate science.
As we seem to write almost on a weekly basis about scientific
inaccuracies in Booker's articles, it's worth noting that the only
defence that the Telegraph have for publishing this sort of
misleading material is that it is classed as 'comment'. Therefore
(in the opinion of the Press Complaints Commission) it is excluded
from the normal requirements of not being "misleading" or
"inaccurate", because the article just reflects Booker's views.
The PCC Editors' code of practice
states:
"The Press, whilst free to be partisan,
must distinguish clearly between comment, conjecture and fact."
It seems to us that there might be a difference between an
article in which, for example, someone suggests a politician is an
idiot - (that's clearly comment) - and an article in which someone
makes a series of basically inaccurate statements about scientific
research. But maybe we're old fashioned.
Perhaps Christopher Booker's bylines should clearly state that
his articles are purely comment and conjecture? This week, he
asserts that:
"The global warming scare has not
continued to unfold as projected by those bent computer models on
which it rested."
And continues:
"Temperatures have not risen as
predicted, the ice caps aren't melting, nor sea levels rising, nor
hurricanes, droughts and heatwaves intensifying as we were assured
they would."
As always, Booker doesn't provide any references to support his
assertions, so we are left guessing at where he gets his
information. His sources certainly don't seem to include
peer-reviewed scientific literature, as a quick check reveals that
Booker's claims are, once again, unfounded and inaccurate.
So...
Global warming has not stopped
Booker starts by echoing the current favourite skeptic meme:
"Temperatures have not risen as
predicted"
This argument usually relies on considering a short sample of
temperature data - and in climate terms, 15 years would fall within
the definition of a short sample, as Peter Stott of the Met Office
explains:
"Fifteen years is just too short a
period over which to measure climate change [...] The world
undergoes natural temperature changes on all kinds of time scales
from daily variations to seasonal ones. It also varies naturally
from year to year and decade to decade."
So it's fair to say that temperatures have risen as predicted,
pauses and all. Short-term pauses in the surface temperature record
are
not unusual in the historical record, and do
appear in climate model simulations of man-made greenhouse gas
increases.
Furthermore, this argument relies on considering only surface
temperature records, and ignoring the oceans completely. In fact,
even when short-term fluctuations give rise to pauses in the
surface temperature record, warming
continues in the deep ocean.
Ice caps are melting
As we have
discussed before, Booker's claim that the "the ice caps aren't
melting" is straightforwardly wrong.
Arctic sea ice is in decline,
and at a faster rate than can be simulated by the climate models
used in the IPCC 2007 report. The world's major ice sheets -
covering Greenland
and the Antarctic
- are also losing mass, and that this ice loss has been getting
faster.
Only Antarctic sea ice is growing, thought to be due to changes
in
how heat circulates in the ocean and changes
in the atmosphere caused by ozone loss above Antarctica.
Crucially, both ice caps are losing mass, again contrary to
Booker's assertion. The gain in Antarctic sea ice
doesn't appear to balance out the decline in Arctic sea ice,
let alone the ice loss from the Greenland and Antarctic ice
sheets.
Global sea level is rising
Satellite measurements show that the world's average sea level
has risen by around 3
millimetres per year since 1993, and this trend is continuing,
as you can see in the graph below.
Global average sea level calculated from satellite
altimetry. Source:
AVISO.
So measurements of global average sea level contradict Booker's
claim: "nor [are] sea levels rising".
Variable outlook for hurricanes, droughts and
heatwaves
Booker moves on to extreme weather, saying:
"nor [are] hurricanes, droughts and
heatwaves intensifying as we were assured they would."
Here Booker makes it sound like predictions of increases in
droughts and intensifying hurricanes were more certain ('assured')
than they actually were.
In fact, scientists have different levels of confidence about
making predictions for different kinds of weather. For example,
although the IPCC's 2007 report says it is "very likely" (implying
90 to 100 per cent likelihood) that heat waves will continue to
increase, scientists don't yet understand other types of extreme
weather so well, including
tropical cyclones (hurricanes) and changes in drought patterns.
Predictions of increases in droughts and hurricanes have therefore
been correspondingly more cautious.
The IPCC's recent review of the scientific literature (the SREX
report) finds that hurricanes and droughts aren't showing clear
changes, so Booker does at least get that right. Heatwaves,
however, have been getting longer in many regions, according to the
SREX report.
Same time, same place, next Monday?