Birds which normally live in the Mediterranean have been colonising Ireland over the last 20 years, indicating global warming is slowly catching up on us.
Species such as the little egret, reed warbler, pied flycatcher, bearded tit, Mediterranean gull, goosander, whitethroat and blackcap have started breeding here, according to scientists.
The birds, according to Dr John Sweeney of the department of geography, NUI Maynooth, have provided some of the best evidence of our changing climate.
"There are relatively good records here in Ireland on birds and they have been very useful in providing supportive evidence of a warming climate," he said.
He said the new bird species began arriving here nearly 20 years ago and in 1997 the little egret began breeding in Cork. Other species such as the Mediterranean gull had also been coming here in the last 20 years as Ireland's climate became warmer.
In addition, the rising temperature meant the earlier arrival of swallows and housemartins over the last decade. "How they get the message down in Africa that it is warm enough to arrive that bit earlier is one we cannot explain, but it is happening," he said.
Research he carried out with colleague Ms Laura McElwain and Ms Alison Donnelly and Mr Mike Johns of Trinity College Dublin established that the 1990s was the warmest decade on record.
It also showed that while the temperature had been rising by an average of 0.3 degrees over the past two decades, Ireland was also becoming wetter. "For instance, Malin Head had had a 40 per cent increase in rainfall in the 1990s and there are indicators that rainfall in the west and north-west is increasing," he said.
Ireland had been lagging behind other European countries in dealing with global warming, but was beginning to conform. This, he said, had implications for all forms of planning and for agriculture and other industries.
Dr Sweeney will be one of the main speakers at the "Pathways to a Sustainable Future" conference on May 15th and 16th in the Royal Hospital, Kilmainham. The conference is organised by the Environment Protection Agency.