I hope the Climate Activists are proud of the effect their lies are having on the younger generation

It is interesting that the 1st IPCC report was quite happy with the Medieval Warm Period and Little Ice Age. They were later ‘homogenised’ out of existence because they didn’t agree with the models.

The original one made the massive mistake of assuming that the weather where you are is the global climate.  The medieval warm period and little ice age were phenomena of the North Atlantic.

What we know is that the Roman Warm Period, the Medieval Warm Period and the Little Ice Age were documented where the population produced documentation. They were obviously of sufficient magnitude to warrant being recorded. The actual temperature changes are much harder to determine, work with various proxies has been carried out, but the influence of more rapidly changing weather systems makes these difficult to determine. Tree rings are affected by temperature and rainfall. Was it a cold year or a dry year?

What is difficult to determine is what happened in areas where there was no population to record any significant changes. One of the many theories suggests that there was a seesaw effect and the southern hemisphere cooled whilst the northern hemisphere warmed, a version of the ocean oscillations. This can only be determined by proxy temperature data which is much harder to calibrate in unpopulated areas.

Changes certainly took place. Is it reasonable to attempt to wipe them from the climate record because they don’t support your theory. True science would adjust the theory to match the data.

Roger Bryant: 
 

I see that the CET series is being mentioned.  

…….

Now we just have scare mongering based on unvalidated computer models and extreme scenarios like RPC8.5.

Do you agree or disagree with Peter Stott's result, which I cited, of how much the rise  in CET since 1950 is due to anthropogenic warming? If you disagree with it, what is your basis?

Quite so, and we need to be very cautious of models that need data ignoring to work well.

Part of the problem is we have only been measuring in the modern way for a very short time, and a great many things could be force fitted to older,  incomplete data.

There is a balance of risks - if we carry on as we are we will comprehensively degrade the planet in a number of ways, warming or not.

Environmentally

I'd not be in favour of clearing Amazon rain forests or burning more coal for power than we really have to,  even if there was not a big question about CO2 levels. The loss of habitat, wildlife etc and the reduction in quality of life from pollution really ought to be enough, nor before we think this is a ‘them problem ’ rather more locally should southern water be putting raw sewage into rivers. It is just not the 20th century any more - any system that makes it cost-effective to behave like that needs to be altered until it is not, and there are so many examples.

Then there is national security, the current political system tends to afford too much power to a small number of, in some cases very nasty, people who happen to control the places the energy comes from. Now that alone should be a call for a bit more independence from fossil fuels than we currently  exhibit.

Have the folk running XR or sitting down on the motorway to raise awareness of insulation all missed the point ? - perhaps, but the fact plenty of folk are now are thinking the shape of the future world at all  is a very good first step. The second is to shape and focus that will to improve things,  into something slightly more nuanced and at the same time truly effective.

Mike.

Peter,

I think that your question may be a little simplistic. As the CET dropped around 0.5°C from 1950 to 1970 the natural forcing effects must be significantly stronger than any ‘man made’ effect. If the effects were equal the temperature would have been flat, not dropping.  The maximum anthropogenic effect here must therefore be rather less than 50%, 25%???. I don’t therefore consider it to be significant.

The cause of the fairly rapid temperature rise from around 1980 to 2000 is interesting. If it was anthropogenic why did it effectively stop? If it was mostly natural why is it missing from the models?

If it was anthropogenic why did it effectively stop? 

It didn't.

Aivar Usk: 
 

Doubling of atmospheric CO2 will add to GHG radiative forcing about 3.5 W/m2 =  2.2% increase, just a nudge! 

Is that right? What is the reasoning behind that estimate? Why do others disagree with it?

 

Surface will radiate 401.5 W/m2 instead of the current 398 W/m2, causing additional warming of 0.75 degC or 0.6 degC 

Is that right? What is the reasoning behind that estimate? Why do others disagree with it?

I would humbly recommend to check the argumentum ad hominem definition. 

I had no intention to start debating the basics within this thread. Since I am not a scientist researching relevant topics, I can point you to the sources for such information 

The trouble is, so far you have been pointing to a bunch of dubious sources. At some point, I have to ask why on earth you believe this stuff. If you can't give any reason (despite having been asked) then that tells us you are not able to judge the scientific worth of the material you are pointing us to. For example:

- for instance, here one can find pointers to climate research and media articles form both the "realist" and "orthodox" lairs, summarized on the weekly basis:

http://sepp.org/the-week-that-was.cfm

Any organisation which wants to lecture us on the application of what they call the Scientific Method is patently willing to express public opinions on stuff they know absolutely nothing about. There is to date no identifiable “Scientific Method” that stands up to much scrutiny. Apparently they don't know that but they write about it anyway. I wonder if it's similar with the rest of what they write?

Maybe so. I notice this week's summary discusses a paper by Richard Lindzen, one of the people you have mentioned. Apparently the paper begins : 

[Lindzen] For about 33 years, many of us have been battling against climate hysteria. We have correctly noted: 1) The exaggerated sensitivity, 2) The role of other processes and natural internal variability, 3) The inconsistency with the paleoclimate record, and 4) The absence of evidence for increased extremes, droughts, floods, wild-fires, and so on.

Look at point 4). Apparently this gentleman doesn't read the newspapers. He wouldn't be ablt to say that in a lecture anywhere in California. Or, I imagine, many places in Louisiana. Or in the Eifel. And it passes in this supposed review also without comment. So there are at least two people not reading newspapers :-)

And I wonder what Lindzen makes of the methodology of estimating increased risk of adverse events, which has been established now for 15 years? If we take point 4) literally, he wouldn't consider those results “evidence”.  

 

I would also remind the ClimateGate - these revelations had only short-lived positive effect on cleaning up the climate science but should not be forgotten:

Politics is fascinating, I admit. But I prefer to discuss here the physical phenomenon/phenomena and imputed phenomena of climate change.

Roger Bryant: 
 

I think that your question may be a little simplistic. 

The question was absolutely clear. The answer is “yes”, or the answer is “no”. Or, maybe, “I don't know”.

If I understand what you say, you are manifestly disagreeing with Karoly/Stott about the results of the paper I cited. You are both talking about exactly the same data set. Either you are right and they are wrong, or they are right and you are wrong, or you are both wrong. Which is it?

Peter Bernard Ladkin:  Which is it?

Two side of the fence we sit. One saying we're doomed unless we blow all our hard earned on discredited CO2 green agenda. The other saying hang on a minute are you really sure about that.

One Example.

In the UK last week scotish wind farms were paid 1.8 million quid from tax payers to stop the turbines for 3 days as the infrastructure is not in place to distribute the energy to where it was needed.

I'm sharpening my pitch fork for that reason alone.

Peter,

As I said above for the given data from 1950 (why was 1950 the chosen startpoint?) the natural effects must be significantly greater than any man made forcing to allow the drop in temperture. Therefore he is wrong, we are both wrong or the datset is incomplete/incorrect.