Tuesday 28 April 2009

EPA report predicts wetter winters and drier summers

AVERAGE TEMPERATURES in Ireland will rise by between 1.4 degrees and 1.8 degrees by 2050, according to a new report on climate change impact published by the Environmental Protection Agency (EPA).

The research also indicates that summer and autumn will warm faster than winter or spring, with the midlands and east warming more than coastal areas.

Winter rainfall is also expected to increase by 10 per cent within 40 years with converse reductions of summer rainfall. The decrease in summer precipitation could be between 12 and 17 per cent.

The report, Climate Change in Ireland: Refining the Impacts for Ireland, suggests that we need to plan for these changes, which are already occurring, but which will be clearly evident within four decades.

The lead author of this report, Prof John Sweeney from NUI Maynooth said that Ireland would experience changes in extremes at both ends of the spectrum.

There would be more rain and more intense rainfall at one end and then heat waves and droughts at the other.

He did qualify the projections.

“Considerable uncertainty still remains in several areas, particularly in relation to rainfall. A risk management type approach to adaptation will be required to take account of these uncertainties.”

The report looks at discrete changes that are expected in different regions of the country, with the largest winter rainfall increases predicted for the midlands.

“By 2050, reductions in summer rainfall of between 20 and 28 per cent are projected for the southern and eastern coasts, increasing to between 30 and 40 per cent by 2080,” it says.

Laura Burke, an EPA director with responsibility for climate change, said: “Climate projections such as those provided in this report enable us to assess potential impacts, plan and take actions to avoid the worst of these and if possible, to utilise positive changes.”

The new projections are in line with earlier reports provided by NUI, Maynooth and Met √Čireann. However, these new projections are based on outputs from a wide range of global climate models, thereby increasing confidence in the projections.

The report states there is an urgent need to adopt appropriate mitigation and adaptation responses to the risks posed by climate change, notwithstanding the challenges of recent economic events.

Detailed studies and research of impacts also highlighted the implications for water resources and also warned about an increase in flood risk, especially in areas that are vulnerable to flooding.

Case studies were presented for a number of the rivers including the Suir, Blackwater (Co Cork), and Barrow.

Among the serious findings was a projection that the return period of the “10 year” flood would reduce to a three-year event on most catchments by 2050.

“The main challenges to Irish agriculture will come from wetter winter and drier summer soils. The impacts will not be uniform across the country. Regional specific adaptation strategies will be required,” state the authors.

It also identifies the most vulnerable habitats as sand dunes, lowland grasslands, mountainous heath, raised bogs, and some fens, turloughs (winter lakes) and upland lakes.

The threat posed to Irish peatlands is also emphasised.

“Increased decomposition of Irish peatlands will be facilitated mainly by cracking during drier summers. Compositional changes within the peatlands will be associated with further deterioration,” it says.

The research concluded that despite the uncertainty inherent in the analysis, there is an urgent need to adopt appropriate mitigation and adaptation responses to the risks posed by climate change, notwithstanding the challenges of recent economic events.

Irish Times


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