Any of you noticed the BOM have been rewriting history again. New "corrections" show a fabricated greater increase in temperature over the century.

Pity for them that there are so many copies of the real data. Will be good evidence when they are charged with conspiracy to defraud.

We know as fact that the oceans are warming, by as much as 2C in places! We know as fact that our oceans are becoming more acidic; and that alone is enough to threaten the food chain; and indeed, our supply of breathable oxygen; two thirds of which comes from the ocean; sometimes described as the lungs of the planet!
Warmer oceans equate to increased rainfall. More atmospheric moisture equates to more trapped radiant heat, even warmer oceans, even more atmospheric moisture, more trapped radiant heat; and well you get the picture?
We know as literal fact that the earth warmed by around 2C around 90 million years ago. The palaeontologic record is like an open book; for those able to accurately interpret it.
When the earth's temperatures rose by just 2C; that was sufficient to allow the methane trapped in the frozen tundras etc; to also begin to melt; adding to the combined greenhouse effect and a total increase in ambient temps by 5C!
5C was enough to almost destroy all life on planet earth and turn places like the united Kingdom; into a wind swept barren salt laden desert, repeatedly swept by winds often in excess of 300klms per!
5C will be enough to threaten all life on the planet once again ;if we don't act to prevent this increasingly real possibility and by as soon as 2070!
Everything including us relies on plant life for food or the very oxygen we breathe! Create conditions that make it almost impossible for that same plant life to grow and prosper; and, we all of us are also threatened with a planet wide extinction event! Rhrosty.

Hasbeen,

You claim to be a scientist and an engineer ... yet, you seem incapable of understanding why some instruments need calibrating with secondary (if not primary) standards ... for example.

If a satellite loses altitude and the altitude is incorporated in the algorithm to calculate a measurement - then obviously, an adjustment has to be made.

The same can be said for the Argo floats (or measurements by BOM) - you so called sceptics scoffed at the re-calibration (holding Willis up as a messiah for the sceptics 'cause' then denigrating him as a Judas for clarifying the discrepancy). Yep, you so called 'sceptics' did it as well with the BEST study (see WUWT). There are many, many, many more examples of your "denial", Hasbeen.

The way you continually rant on, you have absolutely no understanding of the scientific process of observation, measurement, repeatability, quality assurance/control, etc, etc, etc. In fact, your claim to be a scientist and engineer, I would say is a delusion of your hasbeen TAFE days. Either that or you have lost it completely, Hasbeen.

Raw data is one thing, but the hasbeen's of this world are just that - hasbeen. They have no undewrstanding of what the science or engineering is of today.

ps, please feel free to contact BOM directly - and post the response.

Bonmot, the issue as I understand it is that these are not just adjustments to recent temperature figures, but changes to temperature figures that were recorded decades ago. If you would like to explain the rationale by which 'scientists' in 2012 can determine that a temperature that was recorded in, say, 1950 was too high, when the operator is long dead and the weather station no longer there, I would be interested to hear it.

Here's just one example:

http://notalotofpeopleknowthat.wordpress.com/2012/01/25/how-giss-has-totally-corrupted-reykjaviks-temperatures/

Talking about the the poor art of modelling climate change, there are seemingly no end of data being thrown around these days that raise more questions than provide answers, let alone a sound basis for extrapolation modelling. All data requires careful scrutiny.

Take this statement from Rhrosty above for example - "We know as literal fact that the earth warmed by around 2C around 90 million years ago."

Simple enough, ok, I'll believe it, but upon scrutiny, it raises these questions -

1. What warmed? The earth, the ocean or the air?

And then the next statement - "When the earth's temperatures rose by just 2C; that was sufficient to allow the methane trapped in the frozen tundras etc; to also begin to melt; adding to the combined greenhouse effect and a total increase in ambient temps by 5C!"

Let's look at that.

2. "The earth's temperatures rose by just 2C" - What increased in temperature here? The earth (the actual surface rock/soil of the Earth?), the ocean, or mean surface air temperature? What exactly increased by 2C?

It needs definition because it precedes the next bit - "...adding to the combined greenhouse effect and a total increase in ambient temps by 5C!"

3. What is this "ambient" temperature here?

I assume this refers to the mean surface air temperature, which is usually used to indicate the Earth surface temperature. The two are usually taken as being the same. So how can we have two different figures?

4. What should the actual "literal fact" be then? 2C or 5C increase?

The data are ill-defined.

And one more question just for the heck of it -

5. What was the likely cause of the temperature increase around 90 million years ago, whatever it was, 2C or 5C, without human intervention?

It is also noteworthy that around 90 million years ago there was a great deal of tectonic plate and volcanic activity going on and there's quite a bit going on right now in our times too. Significant earthquake reports are occurring almost daily.

Now there's a coincidence.

Jon J, “adjustments” are made to preserve the sometimes innocuous underlying trends in raw data. Changes in; instruments, methods, siting, spatial and temporal discontinuities, etc. arise that have to be 'homogenised'. For example, it would be wrong to assume the way we measure a metric now is the same as it was 100 years ago, or a 1000 years ago, or as voxUnius alludes to - millions of years ago. Indeed, “adjustments” are necessary to cater for longer term time-series trend analysis e.g. how to compare satellite ‘temperature’ analysis to ice-core ‘temperature’ analysis, or how to account for missing or erroneous raw data.

.

voxUnius, if you are really interested in finding out the why's and the wherefore's - I strongly recommend 'Principles of Planetary Climate'.