[R-G] [BillTottenWeblog] Has global warming really stopped?

[Bill Totten]

Mark Lynas responds to a controversial article on newstatesman.com
which argued global warming has stopped

by Mark Lynas

New Statesman (January 14 2008)


On 19 December the New Statesman website published an article {1} which,
judging by the 633 comments (and counting) received so far, must go down
in history as possibly the most controversial ever. Not surprising
really - it covered one of the most talked-about issues of our time:
climate change. Penned by science writer David Whitehouse, it was
guaranteed to get a big response: the article claimed that global
warming has 'stopped'.

As the New Statesman's environmental correspondent, I have since been
deluged with queries asking if this represents a change of heart by the
magazine, which has to date published many editorials steadfastly
supporting urgent action to reduce carbon emissions. Why bother doing
that if global warming has 'stopped', and therefore might have little or
nothing to do with greenhouse gas emissions, which are clearly rising?

I'll deal with this editorial question later. First let's ask whether
Whitehouse is wholly or partially correct in his analysis. To quote:

"The fact is that the global temperature of 2007 is statistically the
same as 2006 as well as every year since 2001. Global warming has,
temporarily or permanently, ceased. Temperatures across the world are
not increasing as they should according to the fundamental theory behind
global warming - the greenhouse effect. Something else is happening and
it is vital that we find out what or else we may spend hundreds of
billions of pounds needlessly."


I'll be blunt. Whitehouse got it wrong - completely wrong. The article
is based on a very elementary error: a confusion between year-on-year
variability and the long-term average. Although carbon dioxide levels in
the atmosphere are increasing each year, no-one ever argued that
temperatures would do likewise. Why? Because the planet's atmosphere is
a chaotic system, which expresses a great deal of interannual
variability due to the interplay of many complex and interconnected
variables. Some years are warmer and cooler than others. 1998, for
example, was a very warm year because an El Nino event in the Pacific
released a lot of heat from the ocean. 2001, by contrast, was somewhat
cooler, though still a long way above the long-term average. 1992 was
particularly cool, because of the eruption of a large volcano in the
Philippines called Mount Pinatubo.

'Climate' is defined by averaging out all this variability over a longer
term period. So you won't, by definition, see climate change from one
year to the next - or even necessarily from one decade to the next. But
look at the change in the average over the long term, and the trend is
undeniable: the planet is getting hotter.

Look at the graph below {2}, showing global temperatures over the last
25 years. These are NASA figures, using a global-mean temperature
dataset known as GISSTEMP. (Other datasets are available, for example
from the UK Met Office. These fluctuate slightly due to varying
assumptions and methodology, but show nearly identical trends.) Now
imagine you were setting out to write Whitehouse's article at some point
in the past. You could plausibly have written that global warming had
'stopped' between 1983 and 1985, between 1990 and 1995, and, if you take
the anomalously warm 1998 as the base year, between 1998 and 2004. Note,
however, the general direction of the red line over this quarter-century
period. Average it out and the trend is clear: up.

Note also the blue lines, scattered like matchsticks across the graph.
These, helpfully added by the scientists at RealClimate.org (from where
this graph is copied), partly in response to the Whitehouse article,
show eight-year trend lines - what the temperature trend is for every
eight-year period covered in the graph.

You'll notice that some of the lines, particularly in the earlier part
of the period, point downwards. These are the periods when global
warming 'stopped' for a whole eight years (on average), in the flawed
Whitehouse definition - although, as astute readers will have quickly
spotted, the crucial thing is what year you start with. Start with a
relatively warm year, and the average of the succeeding eight might
trend downwards. In scientific parlance, this is called 'cherry
picking', and explains how Whitehouse can assert that "since [1998] the
global temperature has been flat" - although he is even wrong on this
point of fact, because as the graph above shows, 2005 was warmer.

Note also how none of the eight-year trend lines point downwards in the
last decade or so. This illustrates clearly how, far from having
'stopped', global warming has actually accelerated in more recent times.
Hence the announcement by the World Meteorological Organisation on 13
December, as the Bali climate change meeting was underway, that the
decade of 1998-2007 was the “warmest on record”. Whitehouse, and his
fellow contrarians, are going to have to do a lot better than this if
they want to disprove (or even dispute) the accepted theory of
greenhouse warming.


The New Statesman's position on climate change

Every qualified scientific body in the world, from the American
Association for the Advancement of Science to the Royal Society, agrees
unequivocally that global warming is both a reality, and caused by
man-made greenhouse gas emissions. But this doesn't make them right, of
course. Science, in the best Popperian definition, is only tentatively
correct, until someone comes along who can disprove the prevailing
theory. This leads to a frequent source of confusion, one which is
repeated in the Whitehouse article - that because we don't know
everything, therefore we know nothing, and therefore we should do
nothing. Using that logic we would close down every hospital in the
land. Yes, every scientific fact is falsifiable - but that doesn't make
it wrong. On the contrary, the fact that it can be challenged (and
hasn't been successfully) is what makes it right.

Bearing all this in mind, what should a magazine like the New Statesman
do in its coverage of the climate change issue? Newspapers and magazines
have a difficult job of trying, often with limited time and information,
to sort out truth from fiction on a daily basis, and communicating this
to the public - quite an awesome responsibility when you think about it.
Sometimes even a viewpoint which is highly likely to be wrong gets
published anyway, because it sparks a lively debate and is therefore
interesting. A publication that kept to a monotonous party line on all
of the day's most controversial issues would be very boring indeed.

However, readers of my column will know that I give contrarians, or
sceptics, or deniers (call them what you will) short shrift, and as a
close follower of the scientific debate on this subject I can state
without doubt that there is no dispute whatsoever within the expert
community as to the reality or causes of manmade global warming. But
even then, just because all the experts agree doesn't make them right -
it just makes them extremely unlikely to be wrong. That in turn means
that if someone begs to disagree, they need to have some very strong
grounds for doing so - not misreading a basic graph or advancing silly
conspiracy theories about IPCC scientists receiving paycheques from the
New World Order, as some of Whitehouse's respondents do.

So, a mistaken article reached a flawed conclusion. Intentionally or
not, readers were misled, and the good name of the New Statesman has
been used all over the internet by climate contrarians seeking to
support their entrenched positions. This is regrettable. Good journalism
should never exclude legitimate voices from a debate of public interest,
but it also needs to distinguish between carefully-checked fact and
distorted misrepresentations in complex and divisive areas like this.
The magazine's editorial policy is unchanged: we want to see aggressive
action to reduce carbon emissions, and support global calls for
planetary temperatures to be stabilised at under two degrees above
pre-industrial levels.

Yes, scientific uncertainties remain in every area of the debate. But
consider how high the stakes are here. If the 99% of experts who support
the mainstream position are right, then we have to take urgent action to
reduce emissions or face some pretty catastrophic consequences. If the
99% are wrong, and the one percent right, we will be making some
unnecessary efforts to shift away from fossil fuels, which in any case
have lots of other drawbacks and will soon run out. I'd hate to offend
anyone here, but that's what I'd call a no-brainer.

Links
{1} www.newstatesman.com/200712190004
{2} www.newstatesman.com/200801140011
_____

Mark Lynas is a climate change writer and activist, author of the
acclaimed book High Tide (Picador, 2004) and fortnightly columnist for
the New Statesman. He was selected by National Geographic as an
'Emerging Explorer' for 2006, and blogs on www.marklynas.orghttp://

www.newstatesman.com/200801140011


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