SINGAPORE – A global slowdown in the growth of nuclear power in reaction to the Japan crisis will seriously hamper the fight against climate change, a top International Energy Agency (IEA) official said Monday.IEA chief economist Fatih Birol told AFP that governments must study the implications carefully before making any decision to retire nuclear power plants earlier than expected or shelve plans for new facilities.”Nuclear is a very crucial part of the global energy mix,” he said in a telephone interview from the IEA headquarters in Paris as Japan battled to place the damaged Fukushima nuclear reactors under control.”A lower nuclear capacity growth in the future may have substantial effect on the global energy mix, energy prices and climate change.”In its annual report released last yea…