Irish climate warming in line with global trends

Ireland : Ireland's climate continues to warm up in line with the global picture, according to the latest data from Met Éireann…

Ireland: Ireland's climate continues to warm up in line with the global picture, according to the latest data from Met Éireann. Last year was the warmest on record for a number of the country's recording stations.

Nor is there any reasonable doubt about what is causing it, according to Séamus Walsh of Met Éireann's climatology and observation division.

"The figures don't really lie. It is 95 per cent certain it is the man-made contribution to levels of greenhouse gases that is the cause. The weight of evidence points to the fact it is anthropogenic."

Ireland has seen an increase in temperatures over the last 100 years, but the rate of increase has been higher in the last couple of decades, he adds. While there has been an average increase of about 0.7° over the country as a whole over that time, the increase has not been uniform.

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There was warming in the period 1910 to the mid-1940s, followed by a cooling period up to the early 1960s, he said. Another period of warming began in about 1980 and it is this trend that has continued, leading to steadily increasing average annual temperatures.

The warming here has accelerated in recent years, with 10 of the 15 warmest years in the last century all occurring since 1990. The last decade is also the warmest 10-year period of the last 100 years, according to the Met Éireann figures.

For the country as a whole, 2006 now ranks as the second-warmest year in the last 100 years, being beaten only slightly by the average reached in 1945.

Last year stands as the warmest year on record at many individual weather recording stations including Casement Aerodrome, Kilkenny, Rosslare, Malin Head and Phoenix Park.

Malin Head and Phoenix Park have observations dating back more than 100 years.

Climatologists take a very conservative view of the data they collate, only slowly drawing conclusions about changes to an established pattern. Mr Walsh says that as recently as four or five years ago there were many who dismissed the notion of climate change, arguing there wasn't enough data, or that natural variability was behind the rising temperatures.

This uncertainty is no longer there. "It is almost universally accepted that temperatures are rising due to man-made causes. Only a minority don't accept it, putting forward arguments that it is due to natural causes."

Reports from the Intergovernmental Panel on climate change make an important contribution to the acceptance of anthropogenic-driven climate change. "As each of these reports arrives, the evidence mounts up. The statistics fairly speak for themselves."

A particularly alarming feature of the climatologists' findings is that if greenhouse gas emissions levelled off tomorrow, we would still see global and local annual temperatures continue to rise for some decades.

"Even if emissions were stabilised at present levels," says Mr Walsh, "because of the way the Earth's systems work we would still have a 0.1° increase per decade coming from the latent heat stored in the oceans. But emission levels aren't going to stabilise."

Met Éireann's figures also show that the annual average wind speed has been reducing almost everywhere in recent years. There have been reductions in the frequency of days with higher wind speeds and in the number of days with higher gusts.

Dick Ahlstrom

Dick Ahlstrom

Dick Ahlstrom, a contributor to The Irish Times, is the newspaper's former Science Editor.