Moderated Global Warming Discussion

[Pixel42]

While it isn't proved yet, it is very likely the open arctic ocean water is leading to changes in the atmospheric circulation, which I introduced early on as the reason climate science suspects is causing the colder winters in parts of the US, Europe, Russia and China.

You introduced? The possible link between Arctic warming, the jet stream and unusually cold spells in certain areas in recent winters has been discussed here for years.

No, but because I had looked at all the regions, I knew it was in one that shows the warmer spring/hotter summer/colder winters pattern. That the 100 year trend showed colder winters was just another serendipitous event. I can also prove that winters there are colder, based on 30 years of data. But you refuse to explain what would be proof to you.

I did explain it. What part of statistical significance at the 95% level did you not understand?

Nobody claimed the trend is global. Even so, I'm curious how that can be claimed. Where is the data the shows this to be a fact?

The same link you've been using. Just click the 'Global' tab rather than the 'US' one.

 

[Brainster]

Interesting article at the Economist.

Temperatures fluctuate over short periods, but this lack of new warming is a surprise. Ed Hawkins, of the University of Reading, in Britain, points out that surface temperatures since 2005 are already at the low end of the range of projections derived from 20 climate models (see chart 1). If they remain flat, they will fall outside the models’ range within a few years.

I do believe in AGW in general, but I also think that the alarmists have exaggerated the effect. The downside is that if the actual recorded temperatures fall completely outside the projected range, deniers will use that to raise doubt about any AGW.

 

[DC]

Interesting article at the Economist.



I do believe in AGW in general, but I also think that the alarmists have exaggerated the effect. The downside is that if the actual recorded temperatures fall completely outside the projected range, deniers will use that to raise doubt about any AGW.

they use that since many years already, the since 10, 11, 12 , 13 ..... 17 years of no significant warming is a common gospel the denialist cult is spreading on the net and media. they somehow think it contradict AGW theory lol. sad its only based on their ignorance and their perfect ignoring of sea temperatures etc.
but your use of the word alarmist is a bit confusing. also your claim of exaggerated the effect. sounds like the usual denialist nonsense.

 

[Pixel42]

the since 10, 11, 12 , 13 ..... 17 years of no significant warming is a common gospel the denialist cult is spreading on the net and media.

I still sometimes see deniers posting Phil Jones' acknowledgement in 2010 that the warming since 1995 was not statistically significant.

http://news.bbc.co.uk/1/hi/sci/tech/8511670.stm

B - Do you agree that from 1995 to the present there has been no statistically-significant global warming

Yes, but only just. I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods.

They are invariably unaware that it only took one more year of data to make the warming statistically significant at the 95% level:

http://www.bbc.co.uk/news/science-environment-13719510

Climate warming since 1995 is now statistically significant, according to Phil Jones, the UK scientist targeted in the "ClimateGate" affair.

Last year, he told BBC News that post-1995 warming was not significant - a statement still seen on blogs critical of the idea of man-made climate change.

But another year of data has pushed the trend past the threshold usually used to assess whether trends are "real".

Dr Jones says this shows the importance of using longer records for analysis.

By widespread convention, scientists use a minimum threshold of 95% to assess whether a trend is likely to be down to an underlying cause, rather than emerging by chance.

If a trend meets the 95% threshold, it basically means that the odds of it being down to chance are less than one in 20.

Last year's analysis, which went to 2009, did not reach this threshold; but adding data for 2010 takes it over the line.

 

[Belz...]

I do believe in AGW in general, but I also think that the alarmists have exaggerated the effect.

Er, of course, worded like that... I mean, don't alarmists always exaggerate ? I think you just wanted to avoid pointing at most people who accept AGW but you erred by rewording your post into a truism.

 

[aleCcowaN]

I do believe in AGW in general ...

I have a problem trying to understand what the verb believe does in that phrase.

...but I also think that the alarmists have exaggerated the effect. The downside is that if the actual recorded temperatures fall completely outside the projected range, deniers will use that to raise doubt about any AGW.

That only means that the projected range was wrong, what is not a surprise as those projections come from knowledge and technology from the previous century.Those projections, and some of the current ones, are as accurate to the climate reality as chemotherapy is effective to cure cancer: everybody has something to criticize, but we would be even worse if we haven't got those.

Don't worry, deniers will use anything available. Those projections show the very long term trend -very long term even for a Japanese point of view- but actual projections are evolving to show the influence of the Earth system, mainly the oceans -which have the "last word" on this subject- and the global temperature depending on the actual heat. In the present state of quick change of the atmospheric composition and emerging land surface there's no surprise when the system shows strange excursions including stagnation and short reversed trends.

 

[aleCcowaN]

The discussion about winters is not that the entire world, or even the NH is cooling. Nobody has said the entire NH is having a colder winter trend. That is absurd, strawman, and shows the lack of comprehension some people bring to the table.

The links I provided show colder winters in some places, most of which really matter to vast populations who live and farm there.

It's like you are telling a sheep farmer with dead livestock his winter was warm, because the global average says so. You can avoid the issue by saying the topic is about the globe, not real world locations. But that makes it useless.

The effects of warming are the most important part of the matter.

If global warming is leading to deadly winters, it's actually more important to know that, than what fraction of a degree warmer it was in the south pacific ocean last year.

But fortunately we are here to neutralize your deleterious prose. If farmers were going to be misguided by your capricious "trends", famines would be much more common.

For any person who knows the slightest bit of statistics and considering the interests you proclaim to care about, not only trends are of a lesser importance, but YOUR trends are just crap: not only those trends are of little value to predict the temperatures during the next agricultural cycle, but YOUR trends would predicts ranges of temperature outside the real ones. Why? Because even an intellectual dwarf understands that temperatures in South Podunk, FL, or Boondocks County, KN and the whole neighbouring State of Franklin during December 2014 will depend more on Cape Town temperatures during 2010, the northern sea ice extension minimum during 2007 or the ENSO 3.4 values for 2011 and not in the local temperatures during December 1915 as your tiddly-dee-trend!s promise.

 

[Dancing David]

He's getting them from this link, which I originally posted:

http://www.ncdc.noaa.gov/cag/

He's been quoting figures derived from it ever since I posted it, though he didn't start quoting the right figures until I explained how to set the parameters correctly.

As Megalon says, it's the concept of whether the trend derived from the figures he's quoting is statistically significant that he now seems to be struggling with.

http://www.ncdc.noaa.gov/cag/
Funny thing
if I set the start year and end year and then the display base period and the trend period all to 1895 and 2013 and the time scale to one year, every month plotted for Illinois shows an increasing trend.

Am I looking at something wrong? By using the time scale of one year instead of one month am I messing things up?

 

[aleCcowaN]

You should get always the same plot. Selecting annual should disable month choice.

 

[aleCcowaN]

For Illinois, negative pseudo-trend for January and July to September, positive pseudo-trend for February to June and November-December. Slightly positive good-for-nothing trend for the whole year.

EDIT: Besides Illinois covering latitudes from Granada, Spain to Lourdes, France, or from the Isle of Naxos, Greece to Sofia, Bulgaria.

 

[BenBurch]

For Illinois, negative pseudo-trend for January and July to September, positive pseudo-trend for February to June and November-December. Slightly positive good-for-nothing trend for the whole year.

EDIT: Besides Illinois covering latitudes from Granada, Spain to Lourdes, France, or from the Isle of Naxos, Greece to Sofia, Bulgaria.

Illinois is also noted for being in a very strange place for weather development.

 

[a_unique_person]

Interesting article at the Economist.



I do believe in AGW in general, but I also think that the alarmists have exaggerated the effect. The downside is that if the actual recorded temperatures fall completely outside the projected range, deniers will use that to raise doubt about any AGW.

The 'alarmists' didn't predict the collapse in the Arctic sea ice, which has been truly alarming.

 

[r-j]

James Hansen, the head of NASA’s Goddard Institute for Space Studies, observes, “the five-year mean global temperature has been flat for a decade.

Denier! He probably believes in the flat earth and hates science.

 

[DC]

Denier! He probably believes in the flat earth and hates science.

actually what you quote showed that Hansen is not a denier at all in regard to climate. which nicely shows the difference between real scientists and the deniers. and also what the deniers made out of it showed their cherry picking and dishonesty.

 

[aleCcowaN]

Illinois is also noted for being in a very strange place for weather development.

Not strange for a state that covers almost half way from the Great Lakes to the Gulf of Mexico.

I wonder if somebody noticed that all plots offered by r-j have deltas of up to 22°F (10°C) in the monthly average within a time span of no more than 4 years. But we had to read about carefully carved "trends" which swung from +0.7°F/century to -1.9°F/century depending on the interval selected. What an idiotic analysis to do if somebody is interested in what is happening locally and how it affects eggplants and cabbages, and not as a part of a great whole.

For the local interest the question is how variability has changed decade after decade.

 

[a_unique_person]

Denier! He probably believes in the flat earth and hates science.

It takes 30 years to get the most reliable time to make an assessment of the long term trend.

 

[CapelDodger]

I do believe in AGW in general, but I also think that the alarmists have exaggerated the effect.

By definition alarmists exaggerate. Do you have anything particular in mind that's been predicted by scientists but hasn't panned out in the predicted timescale?

The downside is that if the actual recorded temperatures fall completely outside the projected range, deniers will use that to raise doubt about any AGW.

If surface temperatures do indeed fall outside the projected range we will all have to reconsider. It's been like that for decades and I've never
found it necessary, but it could happen. Over that time I've seen predictions called alarmist which are now observable, not least in the Arctic Ocean.

When you think about it it isn't AGW that's a problem for societies, it's the effects it has. Predicted effects are an increase in extreme weather events (no sign that that's not happening), more droughts and floods (panning out so far, but who knows, it may turn around in the next few years), stronger storms (again, no evidence against), disruption of glacier- and snowpack-fed hydrology (check), sea-level rise (check). No sign of alarmism in the science, naturally.

So we get onto the social impacts of these changes, which is outside science and hence more vulnerable to hysteria and hyperbolic thinking. This is the realm of the blog and economists and other such dubious characters, but there are some rational predictions from there. The price of food, for instance, depends on production and production suffers from uncertain weather and hydrology. Hence with increased uncertainty comes increased price volatility, on a rising trend. We've been seeing that. Unpicking the AGW effect from the oil-price effect is a playpen for dubious characters with an agenda, but it seems unlikely there's none.

Personally, I'll leave it a few more years before I judge who's been alarmist and who's been complacent. But right now I'll judge as insane Piers Morgan's announcement that the New Little Ice Age has begun.

 

[CapelDodger]

It takes 30 years to get the most reliable time to make an assessment of the long term trend.

How long have deniers been focussed on Hansen now? It has to be getting on 30 years, surely. Mann not so long. You hardly hear about Gore these days, for some reason. But of course playing the man not the ball isn't a trend in denialism, it's a feature.

 

[CapelDodger]

But we had to read about carefully carved "trends" which swung from +0.7°F/century to -1.9°F/century depending on the interval selected.

It shouts "not statistically significant" doesn't it? It's a good illustration of what that actually means.

Anyhoo, that's all wrapped up now. r-j didnt mean winters are getting colder when he said it, they're not, looking back a century only conceals what's happening now and is thus pointless, and nobody gives a toss about benighted sinkholes like Kentucky. No offence meant to Kentuckians but for crying out loud, take a good look around you and move already.

 

[CapelDodger]

Not strange for a state that covers almost half way from the Great Lakes to the Gulf of Mexico.

Quite. It seemed so simple back in my schooldays : there are oceanic climates (the UK) and continental climates (Russia). Lessons didn't touch on Illinois but heck, there was a syllabus to get through.