Ireland could become one of the last remaining refuges in a world crippled by global warming, according to a climate change expert.
Professor Brendan Gleeson, of the National University of Ireland (NUI) at Maynooth, was speaking in the first of a series of lectures on the dangers of climate change, entitled "An Urban World at Risk".
He told the audience that if global temperatures rise by three or four degrees, as he predicts they will, Ireland could become one of only a few habitable 'lifeboat' regions.
He urged governments to consider the potential consequences of an influx of people from around the world fleeing rising seas, drought and destructive weather.
In his speech on Wednesday, Prof Gleeson said: "We cannot know precisely how the disaster will unfold, but the southern megacities in Africa, the sub-continental states and Asia will be the first to go under, taking with them a substantial proportion of our species.
"This will generate enormous migratory shifts, as displaced and stressed populations flee the sea level rise and wildly destructive weather.
"Where are the lifeboats? They are surely the cities, the few cities, in which most of our population resides.
Prof Gleeson claimed that cities in Ireland would be among those that could provide a safe haven as the shift in global climate takes its toll, creating a world that is "much less conducive to human existence".
"For this reason alone Ireland must consider and cannot refuse to engage the climate crisis", he said.
However, there is considerable debate in the scientific community as to whether these apocalyptic conclusions are the right ones to draw.
Dr Andy Kerr, director of the Edinburgh Centre on Climate Change, told the BBC that it was a controversial issue that was not so much a matter of scientific evidence as of personal belief.
"I'm sure we will see rapid changes in climate over the next hundred years but I think we're very capable of surviving," he said.
Dr Kerr agrees that the UK and Ireland will be less impacted by climate change than other areas of the world but does not think we are facing an extinction event: "The whole world won't be coming through Ireland or the UK."
He added that although we may see large shifts in populations during the next century, they are as likely to be driven by social pressures of various forms, as much as environmental factors.