Last year was ninth-warmest in more than 160 years

Last year was the ninth-warmest since record-keeping began in 1850, despite the cooling effect of the weather pattern called La Nina, the World Meteorological Organisation says.

The UN’s weather agency says this marks the 27th year in a row the global average temperature – 58 degrees Fahrenheit (14.45 degrees Celsius) in 2012 - surpassed the 1961-1990 average.

WMO said in its annual climate report the years from 2001 to 2012 were all among the top 13 warmest on record – the hottest being 2010, when the average temperature was 58.2F (14.6C).

WMO Secretary-General Michel Jarraud says “sustained warming of the lower atmosphere is a worrisome sign” of global warming despite La Nina, which is the flip side of El Nino and generally cools the oceans globally.