The key point is that good science involves updating things when new information is available. Not doing so would be wrong.

Oct 18, 2017 at 11:38 AM | ...and Then There's Physics

Good science also involves acknowledging and correcting past mistakes, not adjusting old data to fit, having criticised and ostracised those that have been pointing out the errors.

Golf,
There is a vast difference between a piece of research turning out to be wrong, or turning out to have used a method that we would no longer use today. Research is a process of continual learning; not every step has to be right.

Would also be interesting for you to give an example of someone who has been criticised and ostracised for pointing out errors. The scientific community is often quite pleased to have errors pointed out. The manner in which it is done, and it being blown out of proportion, can - however - have an impact on the response from the broader scientific community.

Schrodinger's cat

Take a look at Spencer and Christy's UAH.

Their earliest reading in 1979 was anomaly -0.33C.

The most recent reading was September, 2017 at 0.54C. That is an increase of 0.87C in 37 years.

To quote Dr Spencer "The linear temperature trend of the global average lower tropospheric temperature anomalies from January 1979 through September 2017 remains at +0.13 C/decade." That is a trend of 0.48C in 38 years.

Uncertainties? Dr Spencer quotes +/-0.1C.

Are you happy with those figures?

ATTP - Raw data is raw data. It needs to be preserved and labelled as such. It is the original record and is therefore the definitive record.

You can massage and correct that record as much as you like but each modified version is just that and should be labelled as such together with full documentation that explains how and why the changes were made. It is therefore up to future researchers to decide for themselves whether the changes were appropriate, justified, an improvement or the proverbial thumb on the scales.

I've never come across researchers who welcome using a constantly changing historical database in ongoing research.

Schrodinger,
1. As far as I'm aware, all of the data is available as are the updates. That's why, for example, there is HadCRUT4.x etc.

2. None of what you've said changes the point that virtually no researcher would present a result using data that had not undergone some kind of analysis. The goal is typically present some kind of signal that you extract from the noise. Sometimes this is easy, sometimes it is not. However, it almost always requires taking the raw data and doing some kind of analysis that allows you to extract a signal that tells you something about the system you are observing.

Here, for example, is a webpage describing updates to the GISS surface temperature data. Here, for example, is a webpage with previous versions of the HadCRUT data.

Entropic Man - Yes, I'm very happy with these figures. I have no idea why we continue to use unreliable, thinly distributed surface stations and almost non-existent buoys then pretend that we can fill in a global grid with measured temperatures.

Perhaps you want me to comment on the temperature increase? That is not surprising at all. I assume that the 300 year warming from the LIA continued during the timescale you mention. In addition, the rapid warming of the thirties seems to have been replicated about fifty years later. Then we have the many, poorly understood, multidecadal cycles some of which have periods which exceed the entire existence of climate science. Then there is the solar activity peak that seems to coincide with the warming period, though there is no causal link identified at present.

The September temperature was of course a delayed response to the high SST seen in June and July. The oceans have shown cooling since then so I would expect the September figures to represent the peak.

RR,
I don't know what counts, I was just interested in who you would regard as having been criticised and ostracised.

Therefore, by your very own admission, aTTP, there is very little science involved in the climate change scam.

Putting words in my mouth? The climate science community seems quite happy with credible critiques. It's less welcoming to ideas that are patently nonsense, and I have no idea why they should be.

If not, have a look at point 3. Perhaps your increase of 0.87°C in 37 years may not be as you assert, if the baseline has been “adjusted”…

How much we've warmed between two time periods does not depend on the baseline.

ATTP- HadCRUT modifications are usually negligible. I am sure that Schmidt and Ruedy always provide detailed documentation about their changes but still leave people wondering why a very high percentages of GISS historical temperatures are adjusted downwards and more recent ones upwards. Still, that seems to be the dominant trend in climate data quality control.

As you said, the goal is typically to present some kind of signal that you extract from the noise. Unfortunately with our climate, the natural variability or noise is very large and not understood, while the global warming signal, if it exists at all, is very small and an act of faith based on a hypothesis and supportive, theoretical models.

The GISS, NOAA and HadCRUT datasets generally agree but they are really inadequate and unfit for purpose in the current age. We should not depend on dodgy algorithms to fill in missing cells in a global grid where a huge number of cells have no data in the first place. The measurements are not reliable, the calibration is not reliable, the siting is not reliable and there are frequent station changes and frequent technology changes.

Satellite measurements are the way ahead. These offer less need and less scope for local adjustment. I would hazard a guess that the breadth of adjustment exceeds the global warming signal by 100%.

Satellite measurements are the way ahead.

Currently, satellite measurements do not measure the surface. My own preference is to use all the information, and to select the dataset on the basis of what I would like to know information about.

These offer less need and less scope for local adjustment.

My understanding is that this is not true. Not only does determining temperatures from satellite data require models, the satellite measurements have undergone (as I understand it) larger adjustements than the surface datasets.

I would hazard a guess that the breadth of adjustment exceeds the global warming signal by 100%.

I'm not quite sure what this means. The largest adjustments that I know of for the surface datasets are the bucket correction (which applied to sea surface measurements and actually reduced the warming trend) and the time of observation correction (which applied mainly to the USA). Globally, I do not think that the difference between the uncorrected and the corrected data is nearly as large as the warming signal.

Schrodinger's cat

Judith Curry posted an article on comparison between raw and corrected data.

https://judithcurry.com/2015/02/09/berkeley-earth-raw-versus-adjusted-temperature-data/

She agrees that the corrections are much smaller than the trend.

RR,
You said (which was what I quoted)

Perhaps your increase of 0.87°C in 37 years

which does not depend on the baseline.

It does if the baseline shifts. What are the apposite absolute temperatures?

Would also be interesting for you to give an example of someone who has been criticised and ostracised for pointing out errors. The scientific community is often quite pleased to have errors pointed out. The manner in which it is done, and it being blown out of proportion, can - however - have an impact on the response from the broader scientific community.

Oct 18, 2017 at 2:38 PM | ...and Then There's Physics

You fail to credit Steve McIntyre for pointing out Climate Science's errors, ignore his work at your blog, yet he accepts your posts at his.

You, and the rest of Climate Science could learn a lot from him, about integrity in science.

Rhoda,
The temperature change over some time interval only depends on the values at the beginning and end of that time interval. It only changes if they change relative to each other.

Golf,

You fail to credit Steve McIntyre for pointing out Climate Science's errors, ignore his work at your blog, yet he accepts your posts at his.

I haven't ignored his work, and I've posted all the comments he's ever made at my blog, so I really don't know what it is that you're complaining about.

Well, use proper temperatures, not slippery anomalies. If it IS an anomaly, don't call it a temperature.

You fail to credit Steve McIntyre for pointing out Climate Science's errors, ignore his work at your blog, yet he accepts your posts at his. 

I haven't ignored his work, and I've posted all the comments he's ever made at my blog, so I really don't know what it is that you're complaining about.

Oct 19, 2017 at 12:53 PM | ...and Then There's Physics

Read what I wrote, not what you replied

Golf,

Read what I wrote, not what you replied

I did. I really don't know what your issue is. I haven't ignored his work.

Radical rodent

Different datasets use different baselines.

GISS anomalies arecbased on the average from 1951-1980. That is 14.0C. To convert from their anomalies to actual temperatures add 14.0. Thus the GISS temperature anomaly for September 2017 is 0.80C, which becomes 14.80C.

UAH anomalies are based on the average from 1981-2010. IIRC that is 14.40C. To convert from anomalies add 14.4.
The September 2017 anomaliy iis 0.54C. That becomes 14.94C

If you want to directly compare anomalies from different datasets Moyhu has graphs here comparing the different anomaly datasets all corrected to a common 1981-2010 baseline.

In a warming world, the later baselines give lower anomalies. Thus UAH with its 1981-2010 baseline gives monthly anomalies about 0.4C lower than GISS with its1951-80 baseline.

EM - Thanks for the useful summary.

I confess to having mixed feelings about our global temperature datasets.

They are inadequate for lots of reasons but they are all that we have. At least they are scrutinised by independent observers so any doubts about their integrity are in the public domain.

I understand the arguments put forward by ATTP in support of GISS data manipulation but I disagree with the practice. Unlike many other sciences, climate science is not really based on experimental evidence and it increasingly uses cascades and even ensembles of models to construct theoretical arguments that are presented as the outcome of experiments.

They are not. Modelling is commonly used in other sciences, in particular, aerospace, engineering and mathematics and its benefits and disadvantages are extremely well understood. These very precise disciplines have strict rules about validation of models.

Climate science appears to have no rules about models and is in great danger of becoming an irrelevant virtual study that produces hypothetical predictions based on hypothetical analyses of hypothetical raw data.

Schrodinger's cat

The experimental evidence is the measurements made at stations, by ships , buoys, balloons and satellites. There are agreed standard procedures for collection of this data, so that it is comparable. These procedures have developed over the period since 1880 as the technology and purposes have changed. Remember, for example, that the network set up by Robert Fitzroy was primarily for storm forecasting around the British Isles, and not for analysing climate change 140 years later. Analysis was by drawing wind, isobar and temperature charts and then using past experience to make local and national forecasts.

Nothing has changed. The primary consumers of measured data are still weather forecasters, sailors and pilots. It is no accident that so many of the long established weather stations are around coasts and airports.

In 1932 the World Polar Year was the first real attempt to think on a global scale. A number of countries cooperated to collect data in the Arctic and Antarctic. The data collection went well, but much of it was subsequently lost during WW2.

The next milestone was the International Geophysical Year in 1957, measuring everything from weather to magnetic fields and mid-ocean ridges. One outcome was the data from which plate tectonics emerged. One lesson learned from the WPY was to set up World Date Centres to secure the data and make it available for study. As a result you can now download raw modern and historical weather data from 14 different centres around the world.

Post-IGY, scientists started thinking about Earth's climate as a single system. Their questions included How do you describe the system? What is it like now? How has it changed? How does it work? How has it changed and how will it change?

The prime tools for answering these questions are the laws of physics and the collected weather data.

This raw data is then processed by a number of different groups of scientists.

Schrodinger,

I understand the arguments put forward by ATTP in support of GISS data manipulation but I disagree with the practice.

This isn't quite what I'm doing. Let me put it a different way. We would like to estimate how global average surface temperatures have changed (or not). If we had a time machine, we could go back in time and install properly calibrated instruments that are in locations that do not change, that are appropriately spaced across the surface, and that record temperatures in a consistent fashion. We can't do this. Therefore we need to use what we do have, which are temperature measurements that were not designed to be used to produce some kind of global average surface temperature. Therefore, you need to correct for things like station moves/changes, changes to the time of observation, changes to the instruments used, etc. Not doing so would be wrong. I don't know enough about what is actually done to have a strong view as to whether or not what they're doing is the best way to do this (but. also, no reason to think it isn't), but it's clear that some kind of analysis has to be done.