Agence France-Presse: World temperatures will cool slightly in 2008, but it will remain among the top 10 hottest years on record, British weather experts predicted Thursday. The impact of a strong La Nina climate pattern over the Pacific will help keep temperatures down, according to the annual forecast by the Met Office and the University of East Anglia. Overall the global temperature is expected to be 0.37 degree Celsius above the long-term average of 14.0 degree, making it the coolest year since …