Oslo - Children in Peru on the front line of a severe cyclical warming of the Pacific Ocean in 1997-98 suffered stunted growth, showing how extreme weather can cause lasting damage to health, a study said on Tuesday.The study of 2 095 children born between 1991 and 2001 in villages around Tumbes in northern Peru found that those born during or just after the El Nino weather system, which caused floods, damaged crops and triggered illnesses such as malaria and diarrhoea, grew less than normal."The El Nino had a big effect by reducing food availability", William Checkley, one of the authors at Johns Hopkins University in the United States, told Reuters. Children under three, a crucial period for growth, were hardest hit.Overall, children in areas apparently hardest hit by floods were 4cm shorter than normal by the age of 10, he said.Stunting has been linked with decreased mental and physical capacity in later life."If adverse weather events affect a significant portion of young children of a country, then they have the potential to adversely affect the future of a community as a whole", said the study by scientists in the United States, Peru and Britain, published in the journal Climate Change Responses.A UN report this month said downpours linked with El Nino events, which typically happen every three to seven years and can disrupt weather worldwide, may intensify because of climate change.Officials from almost 200 governments will meet in Lima from 1-12 December for UN talks about ways to slow global warming. Australia's Bureau of Meteorology said last week that the tropical Pacific was showing renewed signs of El Nino conditions.Another report on Tuesday suggested that investments in nutrition for children were among the best ways to safeguard health in developing nations, yielding benefits of $45 for every $1 spent because of higher expected earnings.Avoiding stunting "should be a top development priority", wrote the authors, Susan Horton of the University of Waterloo in Canada and John Hoddinott of Cornell University in New York state."It turns out that what looks like a good idea morally is also really good economically", said Bjorn Lomborg, head of the Copenhagen Consensus Centre, which commissioned the study.