I might regret this but I have decided to pen a piece on
“global warming”; or to be technical Anthropogenic Global Warming (AGW) or to
be melodramatic Catastrophic Anthropogenic Global Warming (CAGW).
Why do it? Because I fed up with the rubbish being peddled
by the media.
For those who don’t know I was first and foremost a
scientist (a chemist in fact) and whilst I’m now retired science is still a
subject close to my heart. Science is about collecting data, developing
theories from those observations, making predictions based on those theories
and seeing whether the theory is correct ( ie the predictions come true) – and when things don’t work out as
expected refine the theory until it does work or drop the idea and look at
something else. Whilst many scientists still adhere to this tried and tested
method of establishing what is going on in the natural world some seem more
interested in headlines – either for fame and fortune or simply to keep the
research funds rolling in. Whatever; it is the headline seekers that seem to get
the attention of the news media and politicians and their views and predictions, however
flawed, can become “fact” in the public eye.
Around 30 years ago I was convinced by the claims by
scientists that increases in carbon dioxide would warm our planet, the ice
would melt, sea levels would rise and we needed to grow fins and gills……. or
move to higher ground. The would be a
local upside as Deal became Mediterranean in its climate and if sea levels rose
enough the water would flow into the valleys around Kingsdown giving them a
fjord like feel; I was looking forward to opening a marina at the bottom
of my garden (though for that to happen sea levels would have to rise 60 feet or
so).
The threat of rising sea levels was a factor as to why my
wife and I didn’t buy a house in the Sandwich area (that and the house we were looking at not having a
mains sewage system) and why I wouldn’t consider living in North Deal (having
seen it flood in 1978). Needless to say the house in Sandwich is still there
and hasn’t been flooded once in the following 27 years, and neither has North
Deal. I can’t say what happened to the sewage system.
So why was I a believer back then? Simple, I knew carbon dioxide was a greenhouse
gas, coal and oil was being consumed at ever increasing rates and when men of science said something I listened and believed. Seems naive
now.
Now roll the clocks forward 30 years to the present.
I started to get really interested in global warming when I
started bird watching. Was global warming affecting our bird population or not.
Listen to the BBC and the RSPB and the answer would come across loud and clear - it was the
reason for any and every decline in bird numbers being seen (and anything else going on in the world for that matter). However the more I
read the more convinced I became that there was not a lot of truth in what was
being claimed and it became clear that those predicting our future climate were,
to say the least, prone to exaggeration and hype.
My first study was when British (mainly Scottish) seabird
colonies had a string of terrible breeding seasons and a warming sea around our
coast was cited as the cause (a local manifestation of global watering). But I
knew no such problem was occurring in the warmest seas around these islands
(West Wales) so I had a look at the data. My conclusion? Yes the sea have
warmed a little but it was over fishing that decimated the North Sea sand eel
population and caused the poor breeding success of the sea birds; it was
nothing at all to do with global warming. (I posted a blog on this a few months
ago).
Some of our common birds, especially farm birds, are also
suffering a marked decline in numbers. Reason given? Global warming. Again I
couldn’t understand why birds that live and breed successfully from the
Mediterranean to Scandinavia would be affected by a degree or so of
temperature change. For those birds on
the limit of their range a small change in temperature may well cause a rise or
fall in population (eg Dartford warbler; a couple of cold winters and their
population plunges) but it just didn’t make sense for those that live across
wide temperature zones.
So I started looking at the data and the more I looked the
less convincing the arguments looked.
And so to the point of this little essay - what is happening
to global temperatures?
Oh such a simple question but one where the more you think
and read about it the more difficult and confusing the picture becomes.
Firstly it is remarkably difficult to determine what the
actual global temperature is. A lot of the planet is uninhabited, a lot covered
by sea, or ice, or deserts, etc consequently huge gaps exist in temperature
data. These gaps have to be filled with estimated values to build up the global
picture - not exactly black and white. A lot of weather monitoring stations are
also in towns or airports and these areas exhibit increases in temperature over
the surrounding countryside due to human activities (the “heat island effect”)
so again adjustments have to be made. All in all an estimate of the global
temperature involves a lot of estimates and adjustments.
In these days of satellites it should be easier to get an
overall global picture of what is happening but I don’t know enough about what
it is they are measuring from up there – the temperature at ground level being
much higher than those a few thousand feet up and above 10-12,000 feet it is
bloody cold all the time. Also the data doesn’t go back very far.
So with all these caveats here’s what’s going on with the
temperatures.
The above chart shows what is believed to be the global
temperature variation over the last 450,000 years and was cribbed from “Watts
Up With That”
http://wattsupwiththat.com/2014/01/25/when-did-global-warming-begin/#more-102114
who cribbed it from somewhere else (see the Watts Up With That ref). I say
believed because it is estimated from materials trapped in ice cores. Anyway
let’s just assume these are correct because if we don’t there’s nothing to
discuss!
In these charts temperature has been plotted against the “normal
temperature” so warmer than “normal” are positive numbers and cooler than
normal have negative numbers. I have no idea how this normal temperature was
chosen (or what it is for that matter) but what is indisputable is that the
temperature has fluctuated widely from ice ages (below the zero line) to
interglacial periods (like now) where the temperature is above the line (well
sort of). So temperature goes up and down without our influence and warm periods,
like the one we are enjoying, are actually rather unusual; most of the time it
is considerably colder than it is now………… we call these cooler periods “ice
ages”.
If we look at the latest warm period in a bit more detail we
see:
This chart begins at 11,000 years ago where the global
temperature increased as we came out of the last ice age. The temperature then
bounced around the norm (0.0 on right hand scale of top graph) with it being
about 1 degree warmer around 3250, 6900 and 7800 years ago (the highest 3
peaks), about 0.75 degrees colder around 8200 years ago and about 0.5 degrees
colder around 70 years ago when the planet started warming (and where the blue
line flicks up on the extreme right hand side of the graph). So far it looks
like we are in a very normal period of temperature fluctuation.
The red graph is interesting in that it shows carbon dioxide
levels for the same period. From 11,000 to 7500 years ago these were dropping slowly
and since then these have been rising. I have no idea why but it certainly
wasn’t us and our consumption of oil and coal causing it.
From these charts there is no compelling evidence that carbon
dioxide causes global temperatures to increase. In fact you could say the data
seems to suggest the opposite – the last 3000 years show a temperature
declining (albeit erratically) whilst carbon dioxide levels have been
increasing.
I have one more chart to show you. This concentrates on the temperatures
of the last 160 years and so should be the most accurate (with all the caveats
outlined earlier). It also encompasses the temperature kick up seen in the
extreme right of the previous chart.
This chart shows the temperature bouncing around 0.4 to 0.5C
below “normal” from 1850 to 1910, it then rises rapidly from 1910 to 1942 (ish)
to our “normal” temperature where it holds steady till 1980. From 1980 till
2000 it rose rapidly getting to 0.5C above the arbitrary “normal” and since
then there has been NO increase. I repeat there has been NO increase in global
temperature since 2000.
And what was been happening to carbon dioxide levels during this
160 year period?
Atmospheric carbon dioxide concentrations
and global annual average temperatures
over the years 1880 to 2009
This is the plot that has got the global warming believers
hot under the collar. On this time scale overall there has been an increase in
carbon dioxide level and there has been an increase in temperature. However
this observation does not prove one was caused by the other. The British Empire
has been in decline over the same period of time so was that the cause? Carl
Benz patented the first motor car in 1885 so are cars the cause?
If the cause of global warming was truly carbon dioxide it should
stand up to examination. It doesn’t. Note
the time period between 1880 and 1910 – the temperature was falling but carbon
dioxide was rising – no evidence there that carbon dioxide was causing global
warming. Between 1940 and 1980 the temperature was steady but carbon dioxide
levels were rising. And from around 2000 to present the temperature has been
steady again yet carbon dioxide levels have been rising more strongly than ever.
So would you say carbon dioxide was the cause of the temperature changes seen?
I wouldn’t and I hope anyone with an open mind wouldn’t either
From what I have read it is generally believed that carbon
dioxide emissions before 1950 were regarded as too low to have an effect on
temperature. That being the case what caused the 1910 to 1942 warming. Why did
warming stall between 1942 and 1980 just as global emissions took off and finally
why has warming stalled since 2000 – this latest stall being when carbon dioxide
emissions are increasing faster than ever and are at at an all-time high.
So where are we with my original question – what is going with
global warming?
Compared to the ice ages the planet is significantly warmer
but it’s no warmer than it has been on several occasions over the last 500,000
years.
Since 1910 the planet has warmed by around 1C with the rise
coming in 2 bursts one between 1910 and 1942 and the other between 1980 and
2000 and it has been stable since.
Carbon dioxide is a greenhouse gas and so could play a role
in global temperatures modulation but from the evidence presented above the
link is not very strong (being kind) or not there at all (being objective).
So why all the fuss.
As I suggested at the beginning science was once conducted
in dark corners of laboratories and the exponents only came out into the
daylight when they had something to say to like-minded soles. These like-minded
soles would evaluate the claims (face to face or via the learned journals) and
the findings become the new truth…………………. or the theory got kicked into touch.
Now we have the media machine where the prime objective seems to be to sensationalise - remember measles mumps and rubella vaccine?
Are we and our consumption of fossil fuels the cause of the recent temperature rise?
I see nothing compelling in the evidence to say we are
despite carbon dioxide levels rising recently and despite my belief that carbon
dioxide is a greenhouse gas.
I do believe (very strongly) that the global population is
too large and in the long run unsustainable and I do believe that our generation
is consuming too many of the planet’s resources (especially oil and gas) too
quickly.
But there’s little evidence that our consumption of fossil
fuels is driving an increase in global warming.
The planet has gone through a couple of periods of warming
recently but carbon dioxide does not seem to be the cause. To find the real
reason we need the scientists to get back to the old way of working develop
theories that fit the facts. NOT develop theories then refuse to move from
those theories when the data says they are incorrect.
There’s a lot more that could be said about this subject; our
poor knowledge of what really drives climate, the shortcomings in the computer
models, the industries that have grown up around the fear of climate change (wind farms),
the billions being shelled out to fund research into climate change and its
impact……………… but I won’t. I don’t know enough about many of the subjects and
there would be no point because global warming has acquired all the characteristics
of a religion. You either believe or you are a heretic. And when has logical
argument and common sense prevailed in a religious war?