This essay asserts that some people involved in studying and communicating climate change tend to overreact when faced with strong messaging on the need for emissions reductions amid murky science on what's driving some particular extreme phenomenon in the world. There's more at Dot Earth: http://dotearth.blogs.nytimes.com/tag/extremes

1. An essay written for the Dot Earth blog of The New York Times by Thomas
Crowley
Climate Change and Reverse Tribalism
A recent synoptic-scale warming resulted in almost the entire Greenland Ice Sheet in
melt-phase -- a startling but perhaps not unique event (normally about half of the area
undergoes surface melting in any given summer) and due to unusually warm southerly air
flow over the ice sheet.
Almost as troubling as this undoubtedly transient extreme have been quick statements by
some scientists that this has happened before and is probably just natural variability.
While prudence is essential in interpretation of extreme climate change events, it is
troubling that there now seems to be almost a knee-jerk reaction towards invoking natural
variability in followup statements.
Such statements would seem reasonable except for the fact that we can already attribute
global warming, and continental warming to human-induced greenhouse gas climate
change. Careful statistical work indicates this can be done with a considerable degree of
confidence [in IPCC terminology, the warmings are "very likely" (90% probability) due
to manmade climate change].
We would expect detection to sometimes spread into the more regional scale, which,
because it is very noisy, is more difficult to formally detect and attribute to manmade
global warming (the extreme 2003 European heat wave is one example where the formal
process has been successfully applied; the July 2012 Bulletin of the American
Meteorological Society has a recent issue addressing other examples).
In the Greenland case, we already know we are in a phase of record warming over the
United States, very low sea ice level levels in the Arctic, and above-normal temperatures
in Canada. Thus, Greenland is surrounded on one side, the upwind side, by record-
reaching temperatures that look suspiciously like what would be expected from global
warming as it penetrates into the very noisy level of regional scale climate change.
Is it really appropriate to therefore make a kneejerk inference, without any serious
statistical justification, that the present Greenland warming is likely natural variability
(or, slightly differently, mention past variations without uttering the alternate possibility)?
Furthermore, focusing on the proximal cause of the warming is less enlightening than it
seems. Greenhouse gases do not warm the atmosphere in a vacuum - the warming
triggers atmospheric circulation changes. Reflex attribution to high-pressure systems as a
cause dodges the question as to what made the atmospheric circulation change. Such
statements are in a sense pseudo-interpretations; it is like saying that it is warm because
the wind is blowing from the south.
Of course a formal detection and attribution methodologies would need to be applied
before we could more confidently assess the greenhouse gas likelihood. But the counter-
argument is not scientific prudence; it is putting blinders on to the point of being blind to
all but a pinprick of light. It is like pulling rabbits out of a hat; it is seat-of-the-pants
reverse attribution.
In my opinion, this and other examples are cases of reverse tribalism and represents

2. either a conscious or subconscious reaction to public, media, and congressional outcries
and pressure that border on intimidation (especially for government scientists, whose
agencies are vulnerable to retaliatory budget cuts) if one even mutters underneath their
breath, like Galileo, "but it could also be global warming".
I am not advocating some Chicken Little approach to interpreting record climate change
events. I have no patience with climate hysteria and furthermore believe it does more
harm than good, because it invites reverse reactions that impair pubic acceptance of a
more "reasonable" approach to addressing climate change.
But if the geographic scale of a phenomena is very large, it does not seem at all
inappropriate to say something like "the large geographic scale of the warming/melting is
consistent with what we expect from global warming, but the interpretation would have
to be more carefully tested to see if this particular event could be put in that category.
Even if it can't, the warming is certainly consistent with what we expect to happen,
although we wouldn't expect it to happen every year. It could be years or even decades
before it might reoccur.”
But ignoring even the possibility of greenhouse gases as a cause of the observed warming
is like ignoring a dead canary in a mine shift or, worse, looking at the dead canary and
concluding that it died of natural causes.
Thomas Crowley is a retired geologist and climate scientist now living in Scotland. The
CO2 rise in his lifetime is comparable to the postglacial CO2 rise that took almost ten
thousand years to transpire. Virtually no one says that greenhouse gas increase had a
minor/nil effect on late glacial climate change.