On Mar 13, 6:16 pm, "Steve J" wrote:
Well boys and girls, what a hornets'nest last week's channel 4
programme stirred up!

As a teacher, I have to try and put both sides of an argument, and in
this debate this is difficult because all texts, even at A2 level
support the argument for AGW without ant dissent.

That is because the scientific evidence is now strong enough to make
it the only tenable position.

There is a world of difference between having genuine disagreements
about the science and showing the arguments both for and against a
particular interpretation of the data and setting out to deliberately
mislead and misinform the public which is precisely what that program
set out to do.

It might be instructive if it is an A level class to have them look
for the falacious arguments and deliberate half truths used in the
program to give the impression that the anthropegenic component of
global warming was nil.

attempt a balanced presentation.

Balanced in what way? The evidence is pretty clear. You choose not to
look at it and remain wilfully ignorant.

The Economist did a pretty well balanced review on the evidence for
global warming 2-3 years ago. I suggest that you look for article that
if you want some accessible balanced material for your class to look
at.

Are you also going to insist on balanced presentation of both
evolution and Young Earth Creationism in science classes, alien
abduction, flat earth theory in geography. Where do you want to draw
the line?

However, as the various threads on this learned NG domonstrate, there
*ARE* some entrenched views, and some of us do get "hot under the
collar at times in our exasperation at an alternative view. I hold my
hat up to Gianna for some spirited points of view however, and there
should be more room to debate natural cycles of GW.

It is pretty clear that *some* of the global warming *is* due to
changes in the suns output. This is not and has never been in dispute.
The point is that the biggest changes during the past few decades
coincide with a period where the sun has been monitored by satellite
and so no handwaving argument that "it must all be the sun" holds
water.

Too many are afraid to stick their head above the parapet because of
potential abuse from the 'other side'.

Anyway, some things are undeniable IMHO;

1. Global warming is a fact.

So far so good. Although it would be better to say that there is good
observational evidence for global warming.

2. Greenhouse gases heat the atmosphere and preserve life on earth.

Trap more heat in the atmosphere by making it more opaque to outgoing
long wave radiation.

3. Man has burnt fossil fuels almost to exhaustion, so there are more
greenhouse gases in the atmosphere today.

No. There are plenty more fossil fuel reserves to go probably still a
fair multiple of everything we have burnt so far. It just gets
progressively more difficult and expensive to extract. And we can tell
that the build up is from the stuff we are burning because not only is
the atmospheric concentration of CO2 rising, but the isotopic pattern
is changing as more fossil carbon is being added. This would not
happen if natural CO2 were being released from the sea by warming.

4 The climate has been warmer than this many times in the geologic
past.

Although this is true we were never around to witness it. And you
should be careful what you wish for - sudden glitches in global
temperature are almost always associated with serious species
extinction events in the fossil record.

5 Whether Man is responsible for GW or not, burning fossil fuels in
such profusion ia harmful and unsustainable.

The best estimates at present are that in the past few decades our
greenhouse gas forcing has pushed up global temperatures by about the
same amount as the suns change in luminosity over the previous
century. See for example:
http://adsabs.harvard.edu/cgi-bin/np...7ffe fc531242
or if you prefer something by a known AGW sceptic
http://adsabs.harvard.edu/cgi-bin/np...7ffe fc501179
(but note exactly what they are forced to conclude from the
observational evidence despite their well known political bias)

6 The media have over-hyped the AGW scenarioa big time.

They may not have done in terms of ultimate long term damage. The
problem is that it will be many decades before the effects of what we
release into the atmosphere now really take full effect.

7 Governments are now driving energy policies into the 21st century
(like building more nuclear plants in the UK) to combat that overused
term 'climate change'.

At the moment that is our least bad option. Wind power might work for
the UK, but the ones near me are a joke. 2 out of 3 are dead/idle
most days and on one notable occassion the A19 had to be closed after
one self immolated. The UKs largest offshore wind farm has been
offline for ages without anyone noticing. Apparently it cost too much
to bury the cable connecting it to the mainland properly and so it
failed.

8. Climate change is blamed for every "freak" natural atmospheric
hazard from flooding, to hurricanes, to heavy snowfall, to heatwaves,
to gales, to heavy rain, atcetera ad nauseam.

Bound to happen even though it may well be incorrect. It may not be
such a bad thing if it pushes the issue up the agenda in America where
GW denial is still very much mainstream and cars do 20mpg. Warm air
carries considerably more water vapour so there is good reason to
think that it will fuel more powerful storms in the future.

9. Global warming has forced us to implement energy conservation
measures and planning a sustainable future.

I disagree. There were far more convincing "Save It" energy
conservation campaigns during the OPEC induced oil crises of the
1970s. The time is long past for taking all available (and generally
highly cost effective) no-regrets energy saving measures.

10. My last one, to give others a chance, neither side can yet offer
positive proof to the other that their arguments/
eveidence is incontravertible.

One side is claiming this with their eyes shut and their fingers in
their ears. There is a scientific concensus.

Personally, I'm getting sick to death of GW on TV and in the press,
but as an academic debate, this still has a lot of mileage in it just
yet.

The science is clear cut - AGW is real. A few mavericks with huge
political axes to grind and the oil lobbyists make so much noise that
it may seem to the general public that there is still disagreement.
You may recall that the tobacco industry did and does a similar thing
to make sure the suckers all keep on smoking cigarettes.

It is still possible to buy a scientist to testify under oath that
smoking tobacco does not cause cancer - using a carefully crafted set
of words constructed by very sophisticated lawyers. I fully expect the
anti-GW lobby groups to go the same way and that at some stage when
the sea is lapping at the steps of the White House there will still be
someone there being paid to say that you can't prove that it was down
to greenhouse gasses.

Anyone else care to add to my 10 "undeniable points"?

11. Governments of whatever political shade will all seek to use GW as
an excuse for new taxes.

Regards,
Martin Brown