At the time of its establishment the CRU set out four key aims, which still remain valid: • To establish firmer knowledge of the history of climate in the recent and distant past. • To monitor and report on current climatic developments on a global scale. • To identify the processes (natural and man-made) at work in climatic fluctuations and the characteristic timescales of their evolution. • To investigate the possibilities of making advisory statements about future trends of weather and climate from a season to many years ahead, based on acceptable scientific methods and in a form likely to be useful for long-term planning purposes. CRU produces a range of climate datasets, covering temperature,
precipitation, pressure and circulation, both global and regional. One of the CRU's most significant products is the CRUTEM global dataset of land near-surface temperature anomalies on a 5° by 5° grid-box basis, which is compiled in conjunction with the
Hadley Centre for Climate Prediction and Research and its sea-surface temperature dataset to produce the
HadCRUT temperature record. First compiled in the early 1980s, the record documents global temperature fluctuations since the 1850s. The CRU compiles the land component of the record and the Hadley Centre provides the marine component. The merged record is used by the
Intergovernmental Panel on Climate Change in all its publications. This type of dataset can be used to monitor
drought conditions, for example. CRU is also involved in a study of Eurasian climate over the last 10,000 years based upon
tree ring data and a study of European climate in the last 200 years based upon temperature records. The custodians of the raw data are the
National Meteorological Organisations that originated the data; CRU retains most but not all of the raw data, which continues to be held by the originating services. It published a quarterly journal,
Climate Monitor.
Release of raw meteorological data The CRU collates data from many sources around the world. In August 2009 its director, Phil Jones, told the science journal
Nature that he was working to make the data publicly available with the agreement of its owners but this was expected to take some months, and objections were anticipated from National Meteorological Organisations that made money from selling the data. It was not free to share that data without the permission of its owners because of confidentiality agreements, including with institutions in Spain, Germany, Bahrain and Norway, that restricted the data to academic use. In some cases, the agreements were made orally, and some of the written agreements had been lost during a move. Despite this, the CRU was the focus of numerous requests under the
Freedom of Information Act for data used by the unit's scientists.
Nature reported that in the course of five days in July 2009 the CRU had been "inundated" with 58 FOI requests from
Stephen McIntyre and people affiliated with his
Climate Audit blog requesting access to raw climate data or information about their use. In early 2011 a large amount of raw weather station data had been released by the Met Office and the US
Global Historical Climatology Network, but around two-thirds of the data owners did not respond to the CRU requests for agreement, and both
Poland and
Trinidad and Tobago declined. Two FOIA requests for data shared with another researcher were refused by the university, and the requestors appealed this to the
Information Commissioner's Office (ICO). In its decision released on 23 June 2011, the ICO required CRU to release the remaining raw data irrespective of the wishes of the meteorological organisations which owned the data. This decision included data from Trinidad and Tobago but did not cover Poland. The raw data release was completed by 27 July 2011. == CRU email controversy ==