Statement from Professor Trevor Davies, Pro-Vice-Chancellor, Research

The publication of a selection of the emails and data stolen from the Climatic Research Unit (CRU) has led to some questioning of the climate science research published by CRU and others. There is nothing in the stolen material which indicates that peer-reviewed publications by CRU, and others, on the nature of global warming and related climate change are not of the highest-quality of scientific investigation and interpretation. CRU’s peer-reviewed publications are consistent with, and have contributed to, the overwhelming scientific consensus that the climate is being strongly influenced by human activity. The interactions of the atmosphere, oceans, land, and ice mean that the strongly-increasing concentrations of greenhouse gases in the atmosphere do not produce a uniform year-on-year increase in global temperature. On time-scales of 5-10 years, however, there is a broad scientific consensus that the Earth will continue to warm, with attendant changes in the climate, for the foreseeable future. It is important, for all countries, that this warming is slowed down, through substantial reductions in greenhouse gas emissions to reduce the most dangerous impacts of climate change. Respected international research groups, using other data sets, have come to the same conclusion.

The University of East Anglia and CRU are committed to scientific integrity, open debate and enhancing understanding. This includes a commitment to the international peer-review system upon which progress in science relies. It is this tried and tested system which has underpinned the assessments of the Intergovernmental Panel on Climate Change. It is through that process that we can engage in respectful and informed debate with scientists whose analyses appear not to be consistent with the current overwhelming consensus on climate change

The publication of a selection of stolen data is the latest example of a sustained and, in some instances, a vexatious campaign which may have been designed to distract from reasoned debate about the nature of the urgent action which world governments must consider to mitigate, and adapt to, climate change. We are committed to furthering this debate despite being faced with difficult circumstances related to a criminal breach of our security systems and our concern to protect colleagues from the more extreme behaviour of some who have responded in irrational and unpleasant ways to the publication of personal information.

There has been understandable interest in the progress and outcome of the numerous requests under information legislation for large numbers of the data series held by CRU. The University takes its responsibilities under the Freedom of Information Act 2000, Environmental Information Regulations 2004, and the Data Protection Act 1998 very seriously and has, in all cases, handled and responded to requests in accordance with its obligations under each particular piece of legislation. Where appropriate, we have consulted with the Information Commissioners Office and have followed their advice.

In relation to the specific requests at issue here, we have handled and responded to each request in a consistent manner in compliance with the appropriate legislation. No record has been deleted, altered, or otherwise dealt with in any fashion with the intent of preventing the disclosure of all, or any part, of the requested information. Where information has not been disclosed, we have done so in accordance with the provisions of the relevant legislation and have so informed the requester.

The Climatic Research Unit holds many data series, provided to the Unit over a period of several decades, from a number of nationally-funded institutions and other research organisations around the world, with specific agreements made over restrictions in the dissemination of those original data. All of these individual series have been used in CRU’s analyses. It is a time-consuming process to attempt to gain approval from these organisations to release the data. Since some of them were provided decades ago, it has sometimes been necessary to track down the successors of the original organisations. It is clearly in the public interest that these data are released once we have succeeded in gaining the approval of collaborators. Some who have requested the data will have been aware of the scale of the exercise we have had to undertake. Much of these data are already available from the websites of the Global Historical Climate Data Network and the Goddard Institute for Space Science.

Given the degree to which we collaborate with other organisations around the world, there is also an understandable interest in the computer security systems we have in place in CRU and UEA. Although we were confident that our systems were appropriate, experience has shown that determined and skilled people, who are prepared to engage in criminal activity, can sometimes hack into apparently secure systems. Highly-protected government organisations around the world have also learned this to their cost.

We have, therefore, decided to conduct an independent review, which will address the issue of data security, an assessment of how we responded to a deluge of Freedom of Information requests, and any other relevant issues which the independent reviewer advises should be addressed.



Statement from Professor Phil Jones, Head of the Climatic Research Unit, University of East Anglia.

In the frenzy of the past few days, the most vital issue is being overshadowed: we face enormous challenges ahead if we are to continue to live on this planet.

One has to wonder if it is a coincidence that this email correspondence has been stolen and published at this time. This may be a concerted attempt to put a question mark over the science of climate change in the run-up to the Copenhagen talks.

That the world is warming is based on a range of sources: not only temperature records but other indicators such as sea level rise, glacier retreat and less Arctic sea ice.

Our global temperature series tallies with those of other, completely independent, groups of scientists working for NASA and the National Climate Data Center in the United States, among others. Even if you were to ignore our findings, theirs show the same results. The facts speak for themselves; there is no need for anyone to manipulate them.

We have been bombarded by Freedom of Information requests to release the temperature data that are provided to us by meteorological services around the world via a large network of weather stations. This information is not ours to give without the permission of the meteorological services involved. We have responded to these Freedom of Information requests appropriately and with the knowledge and guidance of the Information Commissioner.

We have stated that we hope to gain permission from each of these services to publish their data in the future and we are in the process of doing so.

My colleagues and I accept that some of the published emails do not read well. I regret any upset or confusion caused as a result. Some were clearly written in the heat of the moment, others use colloquialisms frequently used between close colleagues.

We are, and have always been, scrupulous in ensuring that our science publications are robust and honest. 


CRU statement

Recently thousands of files and emails illegally obtained from a research server at the University of East Anglia (UEA) have been posted on various sites on the web. The emails relate to messages received or sent by the Climatic Research Unit (CRU) over the period 1996-2009.

A selection of these emails have been taken out of context and misinterpreted as evidence that CRU has manipulated climate data to present an unrealistic picture of global warming.

This conclusion is entirely unfounded and the evidence from CRU research is entirely consistent with independent evidence assembled by various research groups around the world.

There is excellent agreement on the course of temperature change since 1881 between the data set that we contribute to (HadCRUT3) and two other, independent analyses of worldwide temperature measurements. There are no statistically significant differences between the warming trends in the three series since the start of the 20th century. The three independent global temperature data series have been assembled by:

• CRU and the Met Office Hadley Centre (HadCRUT3) in the UK.
• The National Climatic Data Center (NCDC) of the National Oceanographic and Atmospheric Administration (NOAA) in Asheville, NC, USA.
• The Goddard Institute of Space Studies (GISS), part of the National Aeronautic and Space Administration (NASA) in New York.

The warming shown by the HadCRUT3 series between the averages of the two periods (1850-99 and 2001-2005) was 0.76±0.19°C, and this is corroborated by the other two data sets.

The Intergovernmental Panel on Climate Change (IPCC) in its 4th Assessment Report (AR4) published in 2007 concluded that the warming of the climate system was unequivocal. This conclusion was based not only on the observational temperature record, although this is the key piece of evidence, but on multiple strands of evidence. These factors include: long-term retreat of glaciers in most alpine regions of the world; reductions in the area of the Northern Hemisphere (NH) snow cover during the spring season; reductions in the length of the freeze season in many NH rivers and lakes; reduction in Arctic sea-ice extent in all seasons, but especially in the summer; increases in global average sea level since the 19th century; increases in the heat content of the ocean and warming of temperatures in the lower part of the atmosphere since the late 1950s.

CRU has also been involved in reconstructions of temperature (primarily for the Northern Hemisphere) from proxy data (non-instrumental sources such as tree rings, ice cores, corals and documentary records). Similar temperature reconstructions have been developed by numerous other groups around the world. The level of uncertainty in this indirect evidence for temperature change is much greater than for the picture of temperature change shown by the instrumental data. But different reconstructions of temperature change over a longer period, produced by different researchers using different methods, show essentially the same picture of highly unusual warmth across the NH during the 20th century. The principal conclusion from these studies (summarized in IPCC AR4) is that the second half of the 20th century was very likely (90% probable) warmer than any other 50-year period in the last 500 years and likely (66% probable) the warmest in the past 1300 years.

One particular, illegally obtained, email relates to the preparation of a figure for the WMO Statement on the Status of the Global Climate in 1999. This email referred to a “trick” of adding recent instrumental data to the end of temperature reconstructions that were based on proxy data. The requirement for the WMO Statement was for up-to-date evidence showing how temperatures may have changed over the last 1000 years. To produce temperature series that were completely up-to-date (i.e. through to 1999) it was necessary to combine the temperature reconstructions with the instrumental record, because the temperature reconstructions from proxy data ended many years earlier whereas the instrumental record is updated every month. The use of the word “trick” was not intended to imply any deception.

Phil Jones comments further: “One of the three temperature reconstructions was based entirely on a particular set of tree-ring data that shows a strong correlation with temperature from the 19th century through to the mid-20th century, but does not show a realistic trend of temperature after 1960. This is well known and is called the ‘decline’ or ‘divergence’. The use of the term ‘hiding the decline’ was in an email written in haste. CRU has not sought to hide the decline. Indeed, CRU has published a number of articles that both illustrate, and discuss the implications of, this recent tree-ring decline, including the article that is listed in the legend of the WMO Statement figure. It is because of this trend in these tree-ring data that we know does not represent temperature change that I only show this series up to 1960 in the WMO Statement.”

The ‘decline’ in this set of tree-ring data should not be taken to mean that there is any problem with the instrumental temperature data. As for the tree-ring decline, various manifestations of this phenomenon have been discussed by numerous authors, and its implications are clearly signposted in Chapter 6 of the IPCC AR4 report.

Included here is a copy of the figure used in the WMO statement, together with an alternative version where the climate reconstructions and the instrumental temperatures are shown separately.