[Stoves] RE global warming

[Crispin Pemberton-Pigott]

Dear Grant

Thanks for all the good sources.  I appreciate a little breadth in the
discussion.  I am so fed up with people telling me things that are so
obviously untrue I am willing to provoke things a little.  The Encyl.
Brittanica source was tossed at me be a guy who challenged the idea that
water vapour has any effect at all.  I couldn't believe my eyes when I saw
it really is there in the book!

As for, "Direct emission of water vapour by human
activities makes a negligible contribution to radiative forcing.
However, as global mean temperatures increase, tropospheric water
vapour concentrations increase and this represents a key feedback but
not a forcing of climate change."

This quote is in various forms also found in different places.  If you look
at the meaning of the sentence, it is really saying that "from -15 average
temperature to +16 degrees, water vapour (but not human sources of it) is a
greenhouse gas forcing the temperature up 31 degrees, but above +16 degrees,
water vapour is only a 'feedback mechanism responding to CO2 forcing'".
Apart from being illogical, it is bad science, but cleverly hidden by the
idea that there are two exclusive roles for water that take place at
different temperatures.

There was a popular idea mooted that water vapour played no role at all,
merely holding heat in the atmosphere and moving it around.  The is based on
the idea that water vapour does not absorb infrared radiation, which it
does.  In fact it is far better at absorbing it than CO2.  The misconception
was then confabulated with the idea that some gases are 'forcing gases' and
other are not, even if they both absorb infrared.  Say what?!? That is why
the statement includes a 'keeping in the heat' role for water but 'no role'
in forcing (raising the temperature) in spite of H2O vapour being better at
it than CO2.  Now think about it.  How dumb is that?

To be very clear, that statement presents the idea that water vapour does
not heat the atmosphere on its own, in spite of the fact many papers talk
about whether the heating effect of water vapour alone is 30 degrees or 31
degrees, whether the effect is only 90% of global warming or 95%, or 98%.
The math says that if a forcing gas (water vapour) is also affected by a
feedback mechanism (more water vapour increasing temperatures, raising the
water content of air as the relative humidity remains constant, further
increasing the temperature, leading to more water in the air...) then it
quickly becomes apparent that all global warming can be explained by water
vapour alone. In fact there should be more heating than has been measured so
far so even this model is defective.

Still, this does not really address my main point which is that people have
fiddled their models to make various things appear to be as much of the
cause of climate change as they wish them to be.

For example, the article in Sci Am shows 'global warming' from 1970 to the
present as being something of great concern.  Look at the graph used to show
this.  The author conveniently omits to mention that the graph he uses shows
a cooling for the previous 40 years, and we are nearly back to where we were
in 1930, but not quite.  So for 40 years we cooled down (while CO2 rose) and
now we have been warming for 37 years and are nearly back to where we were
87 years ago (while CO2 rose all the while). Source? His own graph.

Further, the Arctic warmed 6 degrees C between 1890 and 1990, even while the
rest of the world cooled from 1930 to 1970. Source? The Canadian deep hole
ground temperature study that calculated net long term Arctic ground
temperature changes.

I can't say there is or is not global warming and what its cause is or is
not, but I certainly object to the fraudulent or manipulative use of
statistics for the purposes of scare-mongering, followed by the labelling of
anyone who objects as basically, 'Holocaust-deniers' (that, a reference to a
recent statement by one of the founders of Greenpeace quoted in New
Scientist objecting to the fanatical attitude to the subject so often seen
these days).

I am with you on the, " By all means do keep a sceptical eye on it, but do
check what is actually said by the authors themselves, not from newspapers
and magazines..." approach.  Nothing wrong with that.

There is some really good work being done.  I read with great interest the
recent study (using remote-control aircraft) of the brown cloud off the SE
coast of India which is largely coal and biomass smoke.  Fifty % of the long
term heating caused by the cloud was apparently particulate matter from poor
combustion. By that I mean 50% was CO2 and 50% was particulate matter.  How
then did the modellers make CO2 appear responsible for all the heating so
far when the particulate contribution was substantial and unknown?

Just asking...

Regards
Crispin