The Natural Philosopher wrote:

Terry Fields wrote:

No proponent of 'global warming' has exer explained why the planet
oscillates between cold and warm states; the best they can do is claim
that human activity is 'partly' to blame and 'might' accellerate
'global warming'.

Oh, you can't have been listening. Ther are many mecahnisms of localised
psitive feedback. to name buta few

- methane hydrate in the oceans released at a certain temperature along
with CO2 to exacerbate warming.
- polar ice that extends further south and acts as a reflector to
exacerbate global cooling.
- increased desertification causes loss of plant cover, thus reducing
the ability to sink CO2.

Thats 3 positive feedback mechanisms

That's three *potential* local feedback mechanisms, none of which is
man-made.

Who is to say the one isn't balanced by another?

Then there are the impacts on global air and water circulation patterns,
that causes localised changes that may in fact be contrary to the
average global movement of temperature.

As to what triggers these changes, it can be solar activity, volcanic
activity meteorite impact or burning lots of stuff.

I believe that 17000 scientists work on 'global warming', but the case
for it is made by about a tenth of that number.

Whatever you want to think, the fact remains that CO2 is a strong infra
red absorber, and an excess of it in the atmosphere will reduce
re-radiation of heat at night.

No-one has disputed that, and in any case I never said it.

Whatever you want to think, there is absolutely no doubt that
atmospheric CO2 is increasing, and that the amount its increasing
correlates extremely well with world consumption of carbon based fuels.

But that proves nothing. It is merely an observation, like the outside
temperature here is 14 degC.

There was an ice-age in place about 20,000 years ago, whereby the
Salutrians paddled in their kayaks from the south of France to mid
north America, along the edge of the ice-cap. The science that backs
this up is indisputable and it is not a supposition.

Subsequently, the planet warmed and the ice receded. But with probably
only a million people on the planet, living a subsistence lifestyle,
there was no human input whatsoever to the warming of the globe.

So what warmed the globe then, and why isn't it operating now?

What is in contention, are the other complex interrelated mechanisms
that come into play when temperatures start to change. Some of these are
broadly negative feedback, acting to stabilise temperatu others are
positive feedback mechanisms, exacerbating the initial inputs.

Refining these parts of the global model is where climatology is right
now: Arguing about whether its happening at all, or if it is, its not
our fault, is just a political and economic issue.

Possibly; but if CO2-led 'global warming' is a flaky issue - and I've
touched on some of those above - it might not matter.

Not at all. You statement is about as sensible as saying that maybe its
the rain that causes the clouds, as all the rain evoporates and forms
clouds.

I'm afraid that's an evasion.

The evidence is that CO2 lags 'global warming', and no-one now takes
that part of Al Gore's alarmist film with any seriousness.

I wish I could find the reference that said the planet had cooled by
0.7 degC in the last 12 months - a rise of that magnitude would have
been trumpeted from high buildings by the supporters of CO2-led
'global warming'; instead of the current deafening silence.

Annual variations of that order of magnitude are statistically
insginificant: plenty of mechanisms within the models can account for
that. My guess is that arctic ice has melted to a huge extent, and
dumped a load of cold water elsewhere than the poles.

Stop guessing. So far, I haven't guessed anything, but reported the
science.

Consider a bowl of water with an ice cube in it. At the start, you have
a lot of warm water and one cold spot. The ice cube. 'Average' (by area)
temperatures are high. The cube melts, lowering the average temperature.
But in fact the total heat in the system has increased due to absorption
from the room..

Only if the bowl is below room temperature. If the room's at 4 degC
and the bowl at 50 degC, there certainly won't be any net absorption
from the room.

If we measured the total heat in the ecosphere, rather than the average
temperature, it might be a very different story.

No, what we need to do is quantify all the effects. So far only one is
known with any degree of certainty; there are many others that are
known but unexplored, and possibly some currently unknown.

To focus on the one is essentially fraudulent.