Klimaatgekte: Tekst BBC-interview met Phil Jones
Dr. Marc-Alexander Fluks
fluks at COMBIDOM.COM
Tue Feb 16 11:46:51 CET 2010
REPLY TO: D66 at nic.surfnet.nl
Bron: BBC News
Datum: 13 februari 2010
URL: http://news.bbc.co.uk/2/hi/science/nature/8511670.stm
Q&A: Professor Phil Jones
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Phil Jones is director of the Climatic Research Unit (CRU) at the University of
East Anglia (UEA), which has been at the centre of the row over hacked e-
mails.
The BBC's environment analyst Roger Harrabin put questions to Professor
Jones, including several gathered from climate sceptics. The questions were
put to Professor Jones with the co-operation of UEA's press office.
----------------------------------------------------------------
A - Do you agree that according to the global temperature record used by the
IPCC, the rates of global warming from 1860-1880, 1910-1940 and 1975-1998
were identical?
An initial point to make is that in the responses to these questions I've
assumed that when you talk about the global temperature record, you mean
the record that combines the estimates from land regions with those from the
marine regions of the world. CRU produces the land component, with the Met
Office Hadley Centre producing the marine component.
Temperature data for the period 1860-1880 are more uncertain, because of
sparser coverage, than for later periods in the 20th Century. The 1860-1880
period is also only 21 years in length. As for the two periods 1910-40 and
1975-1998 the warming rates are not statistically significantly different (see
numbers below).
I have also included the trend over the period 1975 to 2009, which has a very
similar trend to the period 1975-1998.
So, in answer to the question, the warming rates for all 4 periods are similar
and not statistically significantly different from each other.
Here are the trends and significances for each period:
Period Length Trend Significance
DegC/decade
1860-1880 21 0.163 Yes
1910-1940 31 0.15 Yes
1975-1998 24 0.166 Yes
1975-2009 35 0.161 Yes
B - Do you agree that from 1995 to the present there has been no statistically-
significant global warming
Yes, but only just. I also calculated the trend for the period 1995 to 2009. This
trend (0.12C per decade) is positive, but not significant at the 95%
significance level. The positive trend is quite close to the significance level.
Achieving statistical significance in scientific terms is much more likely for
longer periods, and much less likely for shorter periods.
C - Do you agree that from January 2002 to the present there has been
statistically significant global cooling?
No. This period is even shorter than 1995-2009. The trend this time is
negative (-0.12C per decade), but this trend is not statistically significant.
D - Do you agree that natural influences could have contributed significantly
to the global warming observed from 1975-1998, and, if so, please could you
specify each natural influence and express its radiative forcing over the period
in Watts per square metre.
This area is slightly outside my area of expertise. When considering changes
over this period we need to consider all possible factors (so human and
natural influences as well as natural internal variability of the climate system).
Natural influences (from volcanoes and the Sun) over this period could have
contributed to the change over this period. Volcanic influences from the two
large eruptions (El Chichon in 1982 and Pinatubo in 1991) would exert a
negative influence. Solar influence was about flat over this period. Combining
only these two natural influences, therefore, we might have expected some
cooling over this period.
E - How confident are you that warming has taken place and that humans are
mainly responsible?
I'm 100% confident that the climate has warmed. As to the second question, I
would go along with IPCC Chapter 9 - there's evidence that most of the
warming since the 1950s is due to human activity.
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.
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.
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.
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.
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.
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.
J - Are there lessons to be learned for society or scientists about the way we
see uncertainty and risk?
Yes - as stated by Sir John Beddington - the government chief scientist. And
this doesn't just apply to climate science.
K - How much faith do you have - and should we have - in the Yamal tree ring
data from Siberia? Should we trust the science behind the palaeoclimate
record?
First, we would all accept that palaeoclimatic data are considerably less
certain than the instrumental data. However, we must use what data are
available in order to look at the last 1,000 years.
I believe that our current interpretation of the Yamal tree-ring data in Siberia
is sound. Yamal is just one series that enters some of the millennial long
reconstructions that are available.
My colleague Keith Briffa has responded to suggestions that there is
something amiss with the Yamal tree-ring data. Here is his response:
http://www.cru.uea.ac.uk/cru/people/briffa/yamal2009/
L - Can you confirm that the IPCC rules were changed so lead authors could
add references to any scientific paper which did not meet the 16 December
2005 deadline but was in press on 24 July 2006, so long as it was published in
2006? If this is the case, who made the decision and why?
This is a question for the IPCC.
M - What advice did you seek in handling FOI requests?
The university's policy and guidelines on FOI and the Environmental
Information Regulations are on our website and the information policy and
compliance manager (IPCM) takes responsibility for co-ordinating responses
to requests within that framework. We also have colleagues in each unit and
faculty who are trained in FOI to help in gathering information and assessing
any possible exceptions or exemptions.
I worked with those colleagues and the IPCM to handle the requests with
responses going from the IPCM. He also liaises with the Information
Commissioner's Office where necessary and did so on several occasions in
relation to requests made to CRU. Where appropriate he also consulted with
other colleagues in the university on specific issues.
N - When scientists say "the debate on climate change is over", what exactly
do they mean - and what don't they mean?
It would be supposition on my behalf to know whether all scientists who say
the debate is over are saying that for the same reason. I don't believe the
vast majority of climate scientists think this. This is not my view. There is still
much that needs to be undertaken to reduce uncertainties, not just for the
future, but for the instrumental (and especially the palaeoclimatic) past as
well.
O - Can you tell us about your working life over the past decades in climate
science. Paint a picture about the debate with your allies and scientific rivals
etc.
I have been at CRU since November 1976. Up until 1994, my working life was
almost totally in research. Since 1994, I have become more involved in
teaching and student supervision both at the postgraduate and undergraduate
level. I became a Professor in 1998 and the director of the Climatic Research
Unit in 2004 (I was joint director from 1998).
I am most well known for being involved in the publication of a series of
papers (from 1982 to 2006) that have developed a gridded dataset of land-
based temperature records. These are only a part of the work I do, as I have
been involved in about 270 peer-reviewed publications on many different
aspects of climate research.
Over the years at scientific meetings, I've met many people and had
numerous discussions with them. I work with a number of different groups of
people on different subjects, and some of these groups come together to
undertake collaborative pieces of work. We have lively debates about the
work we're doing together.
P - The "Climategate" stolen emails were published in November. How has
your life been since then?
My life has been awful since that time, but I have discussed this once (in the
Sunday Times) and have no wish to go over it again. I am trying to continue
my research and supervise the CRU staff and students who I am responsible
for.
Q - Let's talk about the e-mails now: In the e-mails you refer to a "trick"
which your critics say suggests you conspired to trick the public? You also
mentioned "hiding the decline" (in temperatures). Why did you say these
things?
This remark has nothing to do with any "decline" in observed instrumental
temperatures. The remark referred to a well-known observation, in a
particular set of tree-ring data, that I had used in a figure to represent large-
scale summer temperature changes over the last 600 years.
The phrase 'hide the decline' was shorthand for providing a composite
representation of long-term temperature changes made up of recent
instrumental data and earlier tree-ring based evidence, where it was
absolutely necessary to remove the incorrect impression given by the tree
rings that temperatures between about 1960 and 1999 (when the email was
written) were not rising, as our instrumental data clearly showed they were.
This "divergence" is well known in the tree-ring literature and "trick" did not
refer to any intention to deceive - but rather "a convenient way of achieving
something", in this case joining the earlier valid part of the tree-ring record
with the recent, more reliable instrumental record.
I was justified in curtailing the tree-ring reconstruction in the mid-20th
Century because these particular data were not valid after that time - an issue
which was later directly discussed in the 2007 IPCC AR4 Report.
The misinterpretation of the remark stems from its being quoted out of
context. The 1999 WMO report wanted just the three curves, without the split
between the proxy part of the reconstruction and the last few years of
instrumental data that brought the series up to the end of 1999. Only one of
the three curves was based solely on tree-ring data.
The e-mail was sent to a few colleagues pointing out their data was being
used in the WMO Annual Statement in 1999. I was pointing out to them how
the lines were physically drawn. This e-mail was not written for a general
audience. If it had been I would have explained what I had done in much
more detail.
R - Why did you ask a colleague to delete all e-mails relating to the Fourth
Assessment Report of the IPCC?
This was an e-mail sent out of frustration at one FOI request that was asking
for the e-mail correspondence between the lead authors on chapter six of the
Working Group One Report of the IPCC. This is one of the issues which the
Independent Review will look at.
S - The e-mails suggest you were trying to subvert the process of peer review
and to influence editors in their decisions about which papers to publish. Do
you accept that?
I do not accept that I was trying to subvert the peer-review process and
unfairly influence editors in their decisions. I undertook all the reviews I made
in good faith and sent them back to the editors. In some e-mails I questioned
the peer-review process with respect to what I believed were poor papers that
had appeared. Isn't this called freedom of speech? On some occasions I
joined with others to submit a response to some of these papers. Since the
beginning of 2005 I have reviewed 43 papers. I take my reviewing seriously
and in 2006 I was given an editor's award from Geophysical Research Letters
for conscientious and constructive reviewing.
T - Where do you draw the line on the handling of data? What is at odds with
acceptable scientific practice? Do you accept that you crossed the line?
This is a matter for the independent review.
U - Now, on to the fallout from "Climategate", as it has become known. You
had a leading role in a part of the IPCC, Working Group I. Do you accept that
credibility in the IPCC has been damaged - partly as a result of your actions?
Does the IPCC need reform to gain public trust?
Some have said that the credibility in the IPCC has been damaged, partly due
to the misleading and selective release of particular e-mails. I wish people
would spend as much time reading my scientific papers as they do reading my
e-mails. The IPCC does need to reassure people about the quality of its
assessments.
V - If you have confidence in your science why didn't you come out fighting
like the UK government's drugs adviser David Nutt when he was criticised?
I don't feel this question merits an answer.
W - Finally, a personal question: Do you expect to return as director of the
Climatic Research Unit? What is next for you?
This question is not for me to answer.
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(c) 2010 BBC News
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