Nightmare weather forecast for homeowners

Your new Wexford summer home has everything

Your new Wexford summer home has everything. It is just a stone's throw from the beach with dramatic sea views from its elevated position above the dunes. It might also end up in the Atlantic before you get a chance to retire.

Global warming, and the climate change that follows it, is with us and there is precious little we can do to stop it. Annual average temperatures are climbing slowly, sea levels are rising and all of the predictions suggest that the Atlantic Ocean will be brewing up much more frequent and powerful storms.

This will mean faster coastal erosion, the potential for more flooding along estuaries and rivers and future trouble for property owners whose prime locations today may be under water or unsellable in 20 or 30 years.

Global warming is being driven by the build-up of so called greenhouse gases in the upper atmosphere, including carbon dioxide and methane. These gases act like an invisible but very effective blanket, allowing energy from the sun to warm the Earth's surface but then trapping it underneath.

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Runaway global warming is theorised to have left the planet Venus with surface temperatures of over 460 degrees C, hot enough to melt lead. We don't face this kind of change but even slightly higher temperatures could mean significant changes.

"There is a big body of evidence that shows that global warming is a reality," stated Dr Peter Coxon, senior lecturer in the Department of Geography at Trinity College. He does not subscribe to scare stories about rising sea levels swamping Dublin and Cork but he does point out that sea level can change dramatically related to temperature.

About 125,000 years ago, when the polar ice caps were small, sea levels were five metres higher than today's levels. But just 20,000 years ago during the last "glacial maximum", when much of Northern Europe was under the Arctic ice cap, sea levels were 120 metres lower.

If the greenhouse theory is correct then larger amounts of greenhouse gases in the upper atmosphere should lead to higher temperatures. This is happening, Dr Coxon said. Average world temperature has risen by about a degree since 1850. Carbon dioxide is expected to double by 2050 however and estimates of temperature change as a direct result vary from an optimistic 2.5 rise to a worst-case scenario of 8 however. Energy is exchanged between the sea and air, something we know as weather. Higher air and water temperatures will mean greater turbulence between the two, he said. "We can expect severe storms to be more frequent." Sea level will rise both because of thermal expansion but also because of more rapid melting of land ice.

Estimates of sea level rise over the next 50 years vary from a few centimetres to half a metre or more. This in itself would hardly be noticeable but when an incoming front whips up a storm surge then coastal damage increases, river estuaries flood and rains swell rivers that can't dump their water fast enough to prevent flooding.

"The waves are generated by the wind. The meteorologists are telling us storms are becoming more frequent and more severe," stated Daragh Cullinan, environment engineer with Wexford County Council.

That county's engineers have seen wide chunks of its territory disappear into the Atlantic due to coastal erosion. The process is a natural occurrence but global warming is expected to speed the whole thing up.