Mail’s ‘U-turn’ coverage of link between extreme weather and climate change
Much was written about the potential links between extreme
weather events and manmade climate change last week, with
Scientific American publishing a three-part special on the
topic, followed by an article in the
Independent entitled:
"Extreme weather link 'can no longer be
ignored'"
The main gist of these articles was that the emerging science of
'climate attribution' is helping researchers determine the
likelihood that human activity has influenced a particular extreme
weather event.
The
Daily Mail's Mail Online had quite a different take on the
story, however, with its own article based on the Independent piece
headlined:
"Global warning: Scientists in U-turn as
they claim extreme weather and climate change are linked"
In adapting the story, the Mail have managed to give quite a
misleading representation of what it's about. First up, the
headline implies scientists previously denied any link between
climate change and extreme weather events, something which is
clearly not true. The scientific community has said for a long time
that an overall increase in extreme weather events is 'consistent'
with climate change projections.
The issue has been one of discussing specific events - an actual
flood, or a particular heatwave. Here, because extreme weather
events are often caused by natural variation in the climate,
scientists haven't made conclusive statements about things 'being
caused by climate change' because there hasn't been enough evidence
to support doing so.
So it's a relatively new thing for climate scientists to suggest
linking individual extreme weather events and climate change, but
there is no evidence ruling out a link between more extreme weather
and climate change in general. Indeed some scientists have been
pointing out the links for quite some time. Kevin Trenberth for
example, head of the Climate Analysis Section at the National
Center for Atmospheric Research,
has said:
"… What I'm sure you've probably heard
is "Well you can't attribute a single event to climate change." But
there is a systematic influence on all of these weather events
now-a-days because of the fact that there is this extra water vapor
lurking around in the atmosphere than there used to be say 30 years
ago. It's about a 4% extra amount, it invigorates the storms, it
provides plenty of moisture for these storms and it's unfortunate
that the public is not associating these with the fact that this is
one manifestation of climate change. And the prospects are that
these kinds of things will only get bigger and worse in the
future."
Unfortunately, as well as giving the piece an overly-strong
headline, the Mail article also totally overplays the new
scientific stance:
"Climate change is inextricably linked
to the extreme weather that has wreaked destruction all over the
world in the last ten years, scientists now claim.
"Experts are convinced of a legitimate link between the two after
more than 20 years of reluctance to blame greenhouse gas emissions
for the heavy storms, floods and droughts which have made global
headlines."
Again, this isn't the case. Only some specific extreme weather
events have been attributed in part to manmade climate change. So
for example, Dr Peter Stott of the Met Office and a team of
researchers
found that the likelihood of the devastating heatwave that hit
Europe in 2003 was very likely to have been doubled by human
activity. But on the other hand, the Russian heatwave of 2010 was
found to result largely from natural climate variation by US
research institution NOAA - not necessarily influenced by human
activity.
Clearly the situation is not as straightforward as it is
presented. Some specific extreme weather events are more likely to
occur as a result of man-made climate change. Others can't yet be
attributed to human activity, and may never be. It's an emerging
scientific field, not a 'U-turn'.
The unfortunate thing about these kinds of articles is that they
give the misleading impression that scientists are always making
big, definite statements about what we do and don't know, when the
reality is that scientists are generally much more cautious about
their conclusions.