The climate has cooled - for sure...

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Since climate researchers (I refuse to call them scientists) are very obviously incompetent liars, and the weather 'forecasters' are political propaganda agencies (as well as being very clearly incompetent - they cannot even describe the current weather, leave aside predicting weather!); the only way to decide about what's going on is by direct personal experience.

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Luckily, with 'global' climate, that kind of thing is very easy - because (at the first level of approximation, which is about as far as we can really understand in something as mega-complex as planetary climate) if the 'global' temperature is rising (or falling), then the temperature of the whole earth surface, thus any specific spot on the globe, will also be rising (or falling). ^

(Unless there is some known reason why this might be subverted, such as - for example - when the thermometer measuring temperature has a furnace built next to it.)

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The only limitation on this inference is concerned with random measurement error - which would be substantial for one small patch of ground and one year, but can be reduced substantially by taking larger areas and observing over several years.

On this basis, the global climate has cooled - with a high degree of probability. I've made the observations.

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Several years ago I decided that the global climate is either warming or cooling (because it is always doing one or the other, except for a few years when at an apex or trough and the trend is changing direction).

All I had to do was see whether there was a new pattern of extremes - and the number of repetitions and annual frequency of these extremes would determine my degree of certainty. My area was Newcastle upon Tyne.

(But the process is retrospective - we know what has happened up to now, but cannot know whether it is valid to extrapolate past trends into the future. At least not until we have made and tested several predictions of future trends - and then we must recognize the limits of this kind of inductive - non causal - reasoning.)

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When we had an exceptionally sustained period of exceptional cold in the winter of 2009-10 I noticed this and began to suspect global cooling; but decided that it would need two more confirmations, close together, before I would be sufficiently sure that the climate was cooling.

The next year - 2010-11 - there was another exceptionally sustained period of exceptional cold which this time began in early November - nobody I spoke with could remember such an early winter in this area ever before.

For 2011-12 the winter was not exceptional - indeed it was quite mild.

But this year (2012-13) we have had another severe winter, although with intermittent rather than continuous snow - culminating in severe cold and snow just two night ago - exceptionally late for snow.

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With three out of four exceptionally cold winters (an unprecedented thing in my lifetime), I regard the observation as sufficiently replicated to state that the Newcastle upon Tyne climate, hence the global climate, has cooled.

If the same pattern of bunched together sustained temperature extremes could be described by specific trustworthy persons at a couple of other reasonable sized areas of the earth's surface, then the hypothesis would be clinched; but in the meantime, and in the absence of such evidence - I know what to believe.

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^NOTE: If, on the other hand, it is assumed that (once random fluctuations have been dealt with) the temperature of one part of the earth's surface can rise while that of another part of the earth's surface is cooling, then the whole concept of a global temperature or climate is challenged.

Indeed if contradictory trends can occur over sustained periods, then there is no such thing as global temperature or climate - unless it is rescued by an auxiliary hypothesis which explains how contradictory sustained trends can occur in the context of a true underlying overall unidirectional trend - and this auxiliary hypothesis would need to be tested separately.

However, I strongly suspect that this kind of auxiliary hypothesis is de facto untestable in a context as complex and uncertain as global climate. Since confirmation would necessarily be prospective (not retrospective), the precision and period of future observation required to discriminate between rival complex hypothesis would make an auxiliary hypothesis designed to explain contradictory climate trends in practice undisproveable.

Only the simple theory of climate change being qualitatively reflected everywhere (absent specific known locally distorting factors, like a furnace or a new-grown city or the like) can be tested in a reasonable time frame. 

(ie. If climate is warming, everywhere warms, and vice versa - the sign of direction of change should be the same, although the quantitative change need not necessarily be to exactly the same extent.) 

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Noted added 19 March - I changed the title of this post from 'is cooling' to 'has cooled' because it is my thesis that humans cannot predict climate beyond saying something like 'next year will probably be similar to this year'. So, I can say, from three out of four exceptionally cold winters, that the climate has cooled; but I can't say whether or not this retrospective trend will continue - because neither I nor anybody else understands the cause of these (small) trends.