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The first three questions I offered before were these:

  • Why do I exist?
  • Why does anything exist?
  • Does anything really exist at all?

Staring with the third of these is necessary. Removing the doubt from this most basic inquiry allows progress to be made on the more – interesting subjects.

The answer to the third question is either ‘yes’ or ‘no’. If the answer is ‘maybe’, it isn’t an answer at all. If the answer is yes, something exists, then there is no problem. The real problem seems to be when the second question ‘how do I know that anything exists?’ follows from the first. This is because it takes us into the world of what ‘know’ might mean.

But it is, really, a false dilemma. For the sake of argument, let it be assumed that what we think of as ‘existence’ does not, actually, ‘really’ exist. What is it that we think is going on then? If not ‘actual’, then it must be imagined – perhaps the dream of a butterfly, or of a divine figure, of a ‘cosmic mind’ – who knows? Perhaps all that we imagine exists is our own fevered dream, and we are trapped in ‘the Matrix’, some kind of dream-state, as in the film of that name.

There are two responses to this; first, if it is imagined, then it must be being imagined by a consciousness of some kind, a ‘mind’ must exist to do the imagining. And if a mind must exist, then something exists, there must be something, in or outside the Universe, which actually does exist. Ah, you say, but what if that mind’s existence is also imagined? Then the step goes one stage farther back. It doesn’t make any difference how far back you take it, at some point, infinitely far down the line, perhaps, at bottom, there must be an existence.

‘Ah,’ you say, ‘but all it might be is radio waves, or electromagnetic forces, or the accidental collision of particles of energy.’ it makes no difference; whatever the cause is of imagined existence, it in itself must exist. So, it is not possible for nothing to exist.

Do you see where this takes us?

The second response (roughly) is this: It makes no difference to us and our lives whether what we think existence is is real or imagined; in terms of how it effects us, both the real and the imaginary have equal power; the imagined may only ‘seem’ real, but that seeming has the force of reality; it is immanent and experienced (or perceived). The status does not change what happens in our lives one jot, permits no escape from some kind of real. It is simpler, then, to accept that what appears to be real actually is real, rather than worry about how real it might not be. In the end, the question is not worth asking: it makes no difference to us, to you.

So, this is the first axiom, or principle, of the meaning of life: Life is real; the world is real, we are real; everything actually exists as it appears to, by and large. To speculate otherwise is pointless. Accept this first: existence is.

And be loved.

 It is possible to argue that discussions of global warming have got out of control in recent months, not just in the media, but within the academic and political arenas, too. But, even if there are exaggerations and examples of hyperbole, there still has to be a baseline position from which a case for optimism can be made. How far can one go with scepticism about GW?

I have done a bit of the required reading – even as far as some of the mathematics – and it is reasonably clear to me that, when it comes to some of the alternative explanations for GW, the numbers really don’t add up; and this isn’t the models’ numbers, its the observed data. Whilst it is possible to argue attributions of warming, it is not really feasible to argue that there hasn’t been a warming trend over the last thirty-five years and, beyond that, over the last hundred. Even if the temperature measurements were all wrong, they are wrong in the same way and show the same trend. Apart from the coincidence that would imply, plus the underlying implication that scientists are incompetent, we’d then have to face the fact that other ‘symptoms’ of warming; ice loss, glacial melt, regional temperature changes, droughts, all show the same general trend. My argument then would be that we have to accept that it has warmed in modern times.

In addition, when I say that ‘it isn’t solar variation’ or ‘it isn’t volcanoes’, these observations are based on the known relationship between measured variations in such forcings and measured variations in temperatures. no models, no assumptions, simple fitting of data to data. If, on top of this, we then posit the hypothesis that at least some of the measurements of some of the variables tend to underestimate them systematically, which is at least a plausible argument, then one possible conclusion we can reach is that the measured forcing of CO2, calculated in relation to these other forcings, may be exaggerated. Because of the physics, I can’t see how it can be eliminated completely as a forcing, however.

Then there comes the issue of climate sensitivity. This is a heavily mathematical/statistical field of research and I simply don’t have the background to critique methods and formulae. I can, however, follow arguments and challenge conclusions. It is in areas like this where I tend to follow the lead of specialists, who not only can do what I cannot, but also offer what I judge, based on my knowledge of logic, to be reasoned and balanced judgements.
As things stand, these specialists have narrowed down the range of equilibrium climate sensitivity (response to a doubling of CO2) to 2-4.5C, very unlikely less than 1.5C, unlikely more than 5C. Most of the main players work with a figure between 2.5 and 3C. Even if their work is based on an exaggeration, it is still hard to reach a climate sensitivity figure below 1.5C.

So,  an individual who was cynical about many of the claims, and dubious about some of the figures offered, can reasonably argue that temperatures are as likely to rise by only 2C as they are by more, if CO2 levels are doubled. Pushed hard, a case might be made for only 1.5C.

But then comes the big political issue; under what circumstances are CO2 emissions limitable to 550ppm? (the doubling). How much CO2 are we going to pump into the system, and how quickly? These are not questions of climate science at all, but political matters, and depend on human actions and decisions, not on how the climate works.

Has it warmed? Is some of the warming human-induced? Is some of the warming able to be fitted into natural variations and forcings? Here, I suggest that the answer to all of these questions must be ‘Yes’. The challenge for the sceptic, if this is the case, is to demonstrate that the human component of climate change is less than has been suggested, and not sufficient to merit undue concern.

Some thoughts on the subject.

Rather than give an opinion based on a personal prejudice (either way), I’ve had another look at the AR4 and come up with some stuff in support of the argument that AGW is exaggerated. See what you think.

Wherever possible, I’ve kept the numbers within the known bounds of probability and the IPCC’s own error bars.

First; it is really hard to argue against the case that CO2 warms the atmosphere, but by how much? The lower estimate of the IPCC is <+1.50 W/M2.
It is also hard to argue that there hasn’t been recent warming, so it has to be coming from somewhere.

Top estimates of solar variation put it at 0.3W/m2, though some reputable people have suggested that this is a conservative estimate: for the sake of argument, let’s say that Stott et. al. (a ‘legit.’ paper, unlike Solanki or some others) are correct. The actual figure ‘should’ be ~0.5W/M2.

What other factors come into play? There has been no recent change in volcanicity, or a major eruption/slowdown in annual outgassing, so the forcing (either way) from volcanoes is still around 0.

What about the Milankovitch cycles?: on the timescales we are dealing with here, no marked change outside normal variations is likely to be measurable, so they don’t account for the changes, in the short term.

Aerosols; an area of ‘low’ understanding and large error bars. Let’s say that the net direct and indirect (cloud albedo) aerosol effect is at the lower end (not so negative) of the estimates: net forcing here would be as low as ~-0.5W/M2.

Positive forcing from Ozone and water vapour are also limited: total of around +0.2w/M2

There are a few other to play with too. What comes out? Even if the forcing from CO2 is 1.5W/M2, the net anthropogenic forcing (positive effects minus negative effects) could be as low as 0.6W/M2 – this is the bottom end of the IPCC estimate. Messing around with the variables allows us to permit the possibility that CO2 forcing is not as high as the best guess, that the negative forcings have had less of a damping effect than has been assumed, that the sun has had a bit more of an effect, and cloud albedo and water vapour numbers, being as they are highly uncertain, favour the ‘not as bad as they are saying’ hypothesis.

What we can end up with (I’m neither advocating nor dismissing this), is a picture of recent human impact on climate which is less than half the ‘assumed’ amounts.

Add to this, that the estimate of climate sensitivity (how much warmer it will get if we double CO2) at the lower end of 2-2.5C.

Add to this, the estimates of sea-level rise, assuming no ‘dramatic’ change and using their number, is as likely to be 20cm in the next 100 years as the upper-end estimates of ~60cm.

Where do we end up? Somewhere close to many so-called ‘sceptics’ position on the AGW debate: By then end of the century, global average temperatures may well be a little less than 2C warmer than they are now. The sea will only have risen 8 inches. Though there are still droughts, hurricanes, melting ice-caps and the like, none of these exceeds our recent experience substantially. The net human input exists, but one part of it has largely been offset by another.

I would argue that this is a scientifically tenable and rational interpretation of the facts, physics and numbers as we have been given them by the IPCC.
No horror stories, no dramatic slide into chaos, no death by flooding or super-hurricane. Good reasons to consider where ocean-side development is viable or not, and good reason to support adaptive strategies by/for the most vulnerable nations. But would it be sufficient grounds to justify radical changes in energy policy? Probably not, though this wouldn’t weaken the argument for change based on pollution issues. Reason enough to justify careful monitoring of the various systems and variables which come into play. Good reason to fund scientific research, as well as social/infrastructure investment.

Reason to panic? Absolutely not. Reason to fear that our world will change beyond recognition? Not really. Reason to be cautious about the long-term decisions we make? We always should be, anyway.

There’s only one snag. In order to subscribe to this particular ‘version’ of the climate change future/AGW debate, it is necessary to accept that there is some human impact on the climate, that the solar impact is significant but not sufficient in itself, that the scientists aren’t entirely wrong about the laws of physics. The only ‘victim’ of this version, really, are the climate models: they are seen to be at best rough approximators of possibility, rather than reliable indicators of most likely outcomes.

So, are there any people who have been pooh-poohed as ‘sceptics’ who are willing to subscribe to this version of ‘scepticism, which does not deny climate change or AGW, but calls into question the assumptions about the extent and associated risks, calls into question the political motivations for action (they are worried about energy, not warming), call into question the Political/ethical conclusions being drawn without reference to the equal possibility of not much change occurring, but doesn’t deny the fundamental science?

Thatis my back-of the-envelope effort at responding to the excessive panic and doom-mongering that AGW invokes. Any takers?


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March 2007