January 21, 2011 View all news BBC News 2010 was the warmest year since global temperature records began in 1850 - although margins of uncertainty make it a statistical tie with 1998 and 2005. The World Meteorological Organization (WMO) concludes 2010 was 0.53C warmer than the average for the period 1961-90 - a period commonly used as a baseline. The 10 warmest years have all occurred since 1998, it notes. The WMO analysis combines data from three leading research agencies, and is regarded as the most authoritative. The three records are maintained by the US-based National Aeronautics and Space Administration (Nasa) and National Climatic Data Center (NCDC), and jointly in the UK by the Hadley Centre and the University of East Anglia's Climatic Research Unit (CRU). They use broadly the same data from weather stations, ocean buoys and satellites across the world; but each analyses that data in different ways, leading to slight differences in their conclusions. The University of Alabama at Huntsville team, which runs the satellite temperature record, has already called 2010 as the second warmest year in its 41-year series, just behind 1998. "The 2010 data confirm the Earth's significant long-term warming trend," said WMO secretary-general Michel Jarraud. READ MORE