The Penguin

Isn't it quiet now? Too quiet. We haven't had a drift to the North Atlantic for ages. Which brings me to a thought. Or two. If a great big mega-ton asteroid landed in the Atlantic, would it A cut of the Gulf Stream and B make a big splash?

FfO, I see what you mean but I’m still interested in the temperature records over the past thousand or so years because a) there are significant changes and human influence was far less. There are a couple of graphs in Wikipedia that illustrate what I mean. http://en.wikipedia.org/wiki/Image:2000_Ye..._Comparison.png http://en.wikipedia.org/wiki/Image:1000_Ye..._Comparison.png As I said in a previous post, the analogy of a hockey stick is misleading as that description alludes to a long period of temperature stability, a straight line on the graph, with a sudden, unprecedented, and dramatic upturn towards the end of the measured period. Looking at the graphs in the above links we see that this is not the case. There were sustained warm and cool periods, ‘medieval warm’ and ‘little ice age’, together with a regime of constantly fluctuating temperatures where hot to cold and vice versa happened as repetitively as they happened suddenly. My understanding is that human activity was imperceptible in the causes of these changes. It’s also notable that, looking at the last thousand years, if the latest period of temperature increases had not occurred the downwards temperature trend would by now have us in an alarmingly cold period. So we could simply be in a period of balancing out. With reference to survivability, we know that, today, people inhabit vastly different environments the world over. From equatorial regions of high temperatures and high humidity to sub-tropical deserts with high temperatures and zero humidity, to polar areas with freezing temperatures and large seasonal changes in humidity. We also know that, as a species, humans have dispersed from one point to all points on the globe, adapting physiologically and technically as they went. In that evolutionary period the climates humans were faced with were more extreme than that referred to in the links. In response then, ffO, I don’t see that we are necessarily faced with imminent extinction, based on the facts currently to hand. I’m not saying there’s no point in looking into the future, but if we do, the assessment should be analytical rather than simply prophetic in it’s primary objective. Quote, Devonian, 2 April 2006 - "No, the change we make is small, but it will have a big impact. Look at it this way: The sun raises temps from close to absolute zero to about -18C. Pre humanity GHG's topped this up to a average world temp of 14C (or so, ball park figures these off the top of my head). People like me are talking of perhaps 2-4C on top of that thanks to anthropogenic ghg's, not much compared to the sun's 270C or so warming is it!!! But 5C cooling is an ice age and 2-4C warming on heck of a lot in climate terms...." Devonian, your point is possibly quite correct – in general terms. My worry, when we’re talking up the high significance of temperature increases slightly over half a degree in a thousand years, is that an argument which relies on terms like ‘14C or so’ and ‘2 – 4C on top of that’ is insufficiently accurate to engender real concern in accurately defined and very small global temperature increases.

ffO, wonderful to see you back, drawn like a moth no doubt to this emotionally charged but factually imperfect debate. Rather than going round in circles gain, we may all now actually learn something. Scribbler. I don't wish to lower the tone of the neighbourhood, (any more than necessary,) but really! We have more influence than the sun? I think not. But that's the point really. I find myself in regular agreement with BFTP, for instance, in the belief that the Earth is a big thing, like massive, and we are wee, very very wee, so although the human race may make tiny adjustments to the climate these are insignificant compared to the ebbs and flows of the natural cycles. As for the hockey stick blade, might this not be just another spike in the handle rather than the defining event in climatic evolution? Chill man, everything's cool. (It certainly bl**dy is today!)

Ha! Fat chance.

That’s why this is so interesting. The dreaded ‘Hockey Stick’ is often waved at us as proof of impending doom. But the ‘ski jump’ end, in terms of actual fluctuation, is not exactly impressive. Further, the handle bit (the previous 900 years) is less like a hockey stick and more like Harry Lauder’s walking stick. (Harry Lauder, for the younger amongst you, was an erstwhile Music Hall performer of the early 20th century whose trademarks were a kilt and a walking stick shaped like a car spring. He was also a school pal of Peter T’s apparently.) In other words, the situation before the latest upturn in global temps has never been stable. So why the panic now? Especially when we wont know the true implications of the current warming in our lifetimes. At least, not mine. And I completely agree about the manners exhibited in this debate.

Thanks, Scribbler, for that pointer – I’d missed the link previously. Having looked at the article now, and although it doesn’t show the correlation of CO2 to temperature I was after it’s still certainly interesting, I am struck by how open the interpretation of the data contained there could be. There is plenty of scope in these graphs for both sides in the GW debate to reference elements of proof in support of their argument. The problem, as it says somewhere in the text, is that we will not be able to truly interpret the data for at least 150 years.

Is it as simple as that though, Scribbler? Leaving aside that you’ve doubled up on your list of examples through repetition, I don’t remember ever seeing a graph of historical organically based energy production plotted against the rise in CO2 levels and global temperature increase. I suppose, as many have pointed out, this would be too simple an analysis anyway due to the many other factors that may influence the climatic system. But it would be interesting to see whether the rather overused mantra “We’ve created an artificial level of CO2 in the atmosphere, so we must be to blame for global warming”, really holds water. But if the model is too simple, then how much more complicated could it be? Do we know? And if we don’t, how can anyone be so certain that there isn’t something else going on; something we can’t yet understand that may have a bigger impact on the climate than human activity?

I may be missing the point again but is what we remember of previous winters in each of our own little bits of the world really relevant. I’m in my late forties (though look much, much younger) and I remember playing in the snows of ’63 and travelling in February of that year from Scotland down to the Northeast of England through miles and miles of frighteningly deep snow, but I doubt if I can base my opinion of climate change on that experience. There very probably are climate cycles that effect changes in chemical composition and temperature of the atmosphere over time. But I doubt if we’re talking about twenty years here, or fifty, or a hundred, or even a thousand years in the frequency of the events associated with them. If I’m right, whether any of us felt colder last Christmas than this Christmas is hardly relevant to climatic change, or shifts in the ocean currents. Although such discussion does remain interesting in any general conversation about the weather.

I don’t know whether CO2 levels were twelve times higher at the start of the last ice age (however you define that,) than they are now, is a fact. I don’t know whether current CO2 levels being at they’re highest for one million or thirty million years is a fact. I am pretty sure there’s nobody around to confirm either fact from first hand experience, so either proposition is purely based on interpolation and is therefore open to challenge. And I’m damn sure nobody looking for today’s big headline is going to bother explaining the qualitative, quantitative, or contextual background to his or her revelation, far less explain an alternative proposition.

You must be much taller than me. I can't see Iceland. I can't see anything north of Manchester.

My first post - I'm not a technical weather wizard but can report sighting of a snowman, 75cm tall, chubby, with red, white & blue scarf on south side of Glasgow at 20.30hrs. Hope this is useful.