Submerged cities and torrential floods just a sign of things to come

This is the third year in a row that Ireland has experienced extraordinary levels of rainfall, both in terms of the amount of rain and the number of intense spells.

And while it is possible to explain our bizarre weather as being within the realms of our "normal" climatic conditions, experts say these events rarely occur so close together and it is reasonable to assume they are caused by climate change.

While the Earth's climate has changed many times over the course of history, what's different about this change is that it is caused by human activities.

The United Nations Intergovernmental Panel on Climate Change (IPCC) is clear: "Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic (produced by humans) greenhouse gas emissions."

Emissions of greenhouse gases, such as carbon dioxide and methane from heavy industry, transport and agriculture, are resulting in increased air and ocean temperatures, drought, melting ice and snow, rising sea levels, increased rainfall and flooding.

Problem

Burning fossil fuels, including coal, oil, gas and peat, to produce electricity adds to emission levels, and changes in land use such as deforestation and urbanisation exacerbate the problem.

Changes have already been noted in Ireland. There is less frost and snow and longer growing seasons for plants and crops.

An analysis of meteorological records by the Environmental Protection Agency's (EPA) Climate Change Research Programme shows a mean temperature increase of 0.7C between 1890 and 2004, with six of the 10 warmest years in Ireland occurring since 1990.

The cost of adapting to these changes will be crippling unless we act fast.

Homeowners face higher energy bills and hikes in their insurance premiums, while extreme summer temperatures will increase the mortality rate among the elderly, adding to pressure on the health service.

Key infrastructure, including power stations, wastewater treatment plants, roads and rail lines, could be destroyed during extreme flooding events.

Today, the Irish Independent reveals details of two internal ESB reports which raised concerns about water management in Cork's Lee valley, saying that the reservoirs in place were too small to cope with extreme weather events.

The reservoirs were designed and built in the 1950s, and will come under extreme pressure in the coming years as flood events become more commonplace -- events they were never designed to handle.

It will be expensive to deal with climate change -- up to €100bn a year will have to be given to developing countries to stave off the worst effects.

But money alone won't solve the problem. We need to reduce our transport emissions. Agriculture emissions must be tackled. Our homes must be better built to retain heat. Renewable clean energy sources are needed.

Just last week, the Academy of Engineers warned that Cork city centre was in danger of being submerged because of global warning.

The same morning, flood waters began to hit Cork and Galway.

That flood threat will become more common in the future. Failure to act now by curbing our emissions and building flood defences will mean expensive clean-up bills over the coming decades.