Ireland's massive flooding has almost certainly been the result of climate change, says Nobel Prize-winner and Ireland's leading climatologist, Prof. John Sweeney.

"We have reaped what we have sown," he said.

Devastating floods have swept large parts of the country. Areas of the south and west of Ireland have been under water in the worst flooding in 800 years, according to experts. Major rivers such as the Shannon and the River Lee have burst their banks and thousands have been evacuated.

Sweeney, of Maynooth College, was one of the climatologists who formed part of the Intergovernmental Panel on Climate Change and won the Nobel Prize in partnership with Al Gore in 2007 because of their warnings about climate change

He pointed out that, per capita, Ireland is one of the largest contributors to climate change, as the country has far- greater greenhouse emissions than Germany, France, and Britain.

Sweeney was also the main author of a report published by the Environmental Protection Agency about the effect on climate change in Ireland. Among his predictions was that winter rainfall amounts would rise steeply in Ireland, which seems to be happening.

"Floods have always been with us and we can't point the finger at any human agency, but the effects of climate change will mean that events like this will become more frequent," he said referring to the flooding

He stated that in some parts of the west of Ireland, it has rained in each of the last 30 days.

Sweeney said that "serious lessons must be learned from this.

"There needs to be more care on where we build new infrastructure and new housing. I have been quite struck in the last number of days by the number of modern housing estates I have seen flooded that are located on flood plains."

It is an Irish brawl sure to keep fans on the edge of their seat, Chris Matthews of NBC has denounced fellow Irish American Sean Hannity as a 'clown and a hyena' because of his comments on global warming.

Read more: Global warming map shows Sligo, Galway and Mayo underwater by 2100