The Phil Jones Interview, Part II

Here is the second part of the BBC's interview with Dr. Phil Jones, one of the world's leading pro-GW scientists-advocates who has been at the center of the Climategate controversy.

F - Sceptics of anthropogenic global warming (AGW) suggest that the official surface record paints a different story from the actual station records. To restore trust, should we start again with new quality control on input data in total transparency?

First, I am assuming again that you are referring to the surface record from both land and marine regions of the world, although in this answer as you specifically say "station" records, I will emphasise the land regions.

There is more than one "official" surface temperature record, based on actual land station records. There is the one we have developed in CRU, but there are also the series developed at NCDC and GISS. Although we all use very similar station datasets, we each employ different ways of assessing the quality of the individual series and different ways of developing gridded products. The GISS data and their program are freely available for people to experiment with. The agreement between the three series is very good.

Given the web-based availability of the Global Historical Climatology Network (GHCN), which is used by both NCDC and GISS, anyone else can develop their own global temperature record from land stations.

Through the Met Office we have released (as of 29 January 2010) 80% of the station data that enters the CRU analysis (CRUTEM3).

The graphic in the link below shows that the global land temperature series from these 80% of stations (red line) replicates the analysis based on all 100% of stations (black line).

http://www.metoffice.gov.uk/climatechange/science/monitoring/data-graphic.GIF

The locations of the 80% of stations are shown on the next link in red. The stations we have yet to get agreement to release are shown in grey.

http://www.metoffice.gov.uk/climatechange/science/monitoring/locations.GIF

I accept that some have had their trust in science shaken and this needs the Met Office to release more of the data beyond the 80% released so far. Before all the furore broke we had begun discussions with the Met Office for an updated set of station temperatures. With any new station dataset we will make sure we will be able to release all the station temperature data and give source details for all the series.

For years, Dr. Jones stonewalled (and, it has been determined by a UK investigation, illegally stonewalled requests for the raw data, but cannot be prosecuted due to Britian’s equlivalent to the statue-of-limitations running out) multiple requests to provide this data. It is still is not completely available as indicated above.

Part of the reason, according to news reports, is that some data was faked and others “adjusted” in a questionable manner. Note, there is much more on these topics, the latter of which is the "Daughter of Climategate" (manipulation of the temperature record about which I still have one more post to make).

G - There is a debate over whether the Medieval Warm Period (MWP) was global or not. If it were to be conclusively shown that it was a global phenomenon, would you accept that this would undermine the premise that mean surface atmospheric temperatures during the latter part of the 20th Century were unprecedented?

There is much debate over whether the Medieval Warm Period was global in extent or not. The MWP is most clearly expressed in parts of North America, the North Atlantic and Europe and parts of Asia. For it to be global in extent the MWP would need to be seen clearly in more records from the tropical regions and the Southern Hemisphere. There are very few palaeoclimatic records for these latter two regions.

This is one of the core issues revealed by Climategate. Remember, “hide the decline” and “the trick”? Some media reports incorrectly equated “the decline” with the recent cooler worldwide temperatures. This was incorrect.

The “decline” referred to the Mann “Hockey Stick” that purported to show no MWP via climate reconstructions from tree cores and other “proxy” data. The last 60 years of this data showed temperatures declining while the instrumental record (see F above) showed warming.

So, they had to “hide the decline.” That was done via “the trick.” In the illustration, the yellow line is the original temperature reconstruction, the red is the instrumental record. Note the reconstruction shows cooling (declining) temperatures while the instrumental record show warming.  “The trick” is shown in the blown up image from the which was to stop the reconstruction temperature line (in this case shown in green) before the decline started and hope that, in the spaghetti of the lines, no one noticed. It was Steve McIntyre who uncovered this scandal.  

Not only was this a mockery of science, it calls into question these 1000 year climate reconstructions.  If they don’t agree with the instrumental record in recent years, why would they produce accurate results 800 years ago?

Of course, if the MWP was shown to be global in extent and as warm or warmer than today (based on an equivalent coverage over the NH and SH) then obviously the late-20th century warmth would not be unprecedented. On the other hand, if the MWP was global, but was less warm that today, then current warmth would be unprecedented.

There is no doubt there was a Medieval Warm Period, the evidence is overwhelming. We don’t know, for sure, whether the MWP was in the Northern Hemisphere (only) or the entire world. 

We know from the instrumental temperature record that the two hemispheres do not always follow one another. We cannot, therefore, make the assumption that temperatures in the global average will be similar to those in the northern hemisphere.

I agree, we just don’t know.

For more, see the answer to question Q.

H - If you agree that there were similar periods of warming since 1850 to the current period, and that the MWP is under debate, what factors convince you that recent warming has been largely man-made?

The fact that we can't explain the warming from the 1950s by solar and volcanic forcing - see my answer to your question D.

But, we can’t explain the cause of the MWP.  If we can’t explain the past, how can we explain the present and future?

I - Would it be reasonable looking at the same scientific evidence to take the view that recent warming is not predominantly manmade?

No - see again my answer to D.

His “evidence” that the answer is “no” are the same computer models that utterly failed to forecast the flat to lower temperatures of the last dozen years. If they can’t get twelve years right, why believe they can get 120 years correct?

Part III still to come.