That's entirely up to you, Poirot.

Joe

Loudmouth, you must be squinting again. It reminds me of the old rhyme about the donut. You have your eye firmly on the hole. If you take you focus off the noise in the graph, you would see the trend better. It is the long term average you need to look at. Before you carry on about the fact that it hasn’t gone anywhere for the past few years, I will point out that this has happened several times in the past 30 years – indeed it has gone down on occasions – only to begin its inexorable rise again. That is the influence of La Nina periods.

Any claim that the curve will continue down based on some notion that it should be concave is simply more bull. There is a powerful mechanism, where the physics and chemistry are well understood, that will drive the temperature up further.

And finally, just to deflate the no warming for the last 14 years claim, I took the data since 1998 and plotted a trend line through it. The slope is upwards at 0.9 degrees per century. The same average rate for the last century. All this focus on the rather unusual 1998 reminds me of another old saying about 1 swallow not making a summer.

Hi Agronomist,

Thank you for clarifying a few points. But are you saying that the current rate of increase in temperatures, i.e. since 1998, is no greater than the rate for the twentieth century as a whole ? 0.9 degree/century ? There is no acceleration, no exponential growth ? That any presumed growth has levelled off ? Even though CO2 production is rising ?

I'm open to persuasion, but only from evidence. If you assert, then you must prove. It's not up to me or anyone else to do it for you. Accusations of 'bull' are not really congenial to persuasion.

Cheers,

Joe

Joe, it's a common fault of the so called “climate sceptics” to confuse short-term “noise” (natural variability) with the long-term “signal” (AGW).

Some people here deliberately obscure this inconvenient fact of time series statistical analysis. This demonstrates to me how little they understand statistics or how much they want to deliberately distort or misrepresent it.

Take your pick; cognitive dissonance or confirmation bias – in either case, they want to find a reason to not believe in the science.

Poirot’s link to the graph ‘what sceptics think and what realists think’ is correct. The ‘sceptics’ are not looking at the long term trends; they deliberately (or in their ignorance) highlight short term noise. Indeed, the typical purveyors of “cherry picks” start and finish at points to suit their beliefs (motivational reasoning).

So you want curves, Joe – how about this?

http://tinyurl.com/Joe-Curves

BTW, that black curve was statistically computed by BEST (I told you about them previously but perhaps you have forgotten). BEST was headed by Professor Muller, that climate sceptic (in the scientific meaning of the term) who is now considered a 'fake' by the usual suspects who once held him up so high in their esteem of him.

Joe, you don’t have to believe in AGW or how serious it is. However, if the likes of the Tony Lavis’s of this world are anything to go by - sipping whatever they’re sipping or smok'n whatever they’re smok'n, we should be alarmed – about inaction and slumping into a warm and fuzzy haze.

A different type of alarm to the likes of the UN Security Council, who are concerned about our energy use/abuse, or food and water security, etc. as we head towards a 10 billion population in about 40 years’ time.

Sheesh, even this lot were concerned then:

http://www.ens-newswire.com/ens/apr2007/2007-04-16-05.asp

More so now:

http://www.guardian.co.uk/commentisfree/cifamerica/2011/may/20/climate-change-climate-change-scepticism

Avagoodweek :)

PS: your last comment. Joe, been over it before and there's much in the literature and it's really not that hard to do your own homework.

You either just don't get it or you just don't want to. My guess, the latter :(

Thank you, Bonmot. Hansen's Curve is still puzzling: of course, the dip in the last few years doesn't mean much in the longer term, except that it hardly confirms the AGW hypothesis. I'm more concerned about why the curve itself is slightly convex - rather than concave, or VERY concave - over the years since 1970, years of rampant CO2 production.

I admit to having little statistical knowledge, but at least I can see whether or not a graph is going up or down, or a trend is accelerating or decelerating. And of course one can fit a line to data as one chooses, it depends on the averaging involved. In Hansen's Curve, I'm puzzled why there seems to be a decline in average temperature during the period 1940-1970, not generally years of economic stagnation and minimal CO2 production. I guess there is a time-lag in the effects of CO2 on temperature, but if so, why the dip since 1998 ? Why not an accelerated rise right since 1970 ? i.e. a concave curve ?

Of course, I may be just showing my ignorance here, but I'm trying to honestly understand what are very complex processes. And I don't want to be conned with some appeal to authority: the authority of the IPCC generally and Pachauri in particular with his predictions about glacier extinction over the next 23 years - when even the NSW snow-fields seem to be doing fine (or am I mixing weather and climate here ?) - are hardly confidence-building.

Yes, AGW is probably an issue but currently, on my scale, it ranks somewhere along with same-sex marriage and population-explosion, storms in tea-cups, yada yada stuff, no big deal. But as a voter, I'm willing to be persuaded properly.

Cheers,

Joe

Joe, perhaps you want to see the trees instead of the forest.

This may sound tedious but it is a point that you seem unable to appreciate (even when you admit to having little statistical knowledge - and not least in time series analysis):

Nevertheless, I will try and explain once more, writing slowly:

The bumps and wiggles (concave or convex) is “noise” – natural variability.
The AGW “signal” (unnatural variability) is superimposed on this noise.

The noise must be filtered out to see the relatively long term trend.

When you do this, the long term trend is up, despite the bumps and wiggles and despite your eyeball.

Global Warming does not mean the globe will warm every year.

As far as increasing ‘heat trapping’ greenhouse gases go, they will likely increase exponentially, unlike temperatures.

The black curve is not “Hansen’s curve”, it is from Professor Muller’s BEST (Berkeley Earth Surface Temperature) analysis. You have been given the detailed links before.

For your post 1940 query; it is well known to people that do inquire of the records in the literature, that aerosols had a cooling influence. Environmental pollution laws were less robust then.

You say “of course one can fit a line to data as one chooses, it depends on the averaging involved”.

No Joe, you obviously didn't understand my previous comment, and it really is becoming tiresome.

You don’t want to “conned with some appeal to authority: the authority of the IPCC generally and Pachauri in particular”?

Ok then, appeal to the amateurs and wannabes - there's plenty around here.

Should I expect someone who has such an abiding interest in things you have raised know at least the issues, workings and resultant resolutions of the IPCC? Of course!

As to the NSW snow-fields; have you actually seen the trend since the 60’s? Bumps and wiggles Joe.

I’m a voter too, Joe – but I'll be voting on issues that's progressive for future energy policy, amongst other things. On my scale, I will be dead when those decisions will come back to bite, or not : )
Cheers