The heartbreaking scenes of devastation caused by the recent floods are a reminder that the cost of ignoring the current and coming impacts of climate breakdown will be huge. Of course we quickly forget the last event, and think it will never happen to us anyway. But at the same time, we know that the contribution we are making to enhancing extreme events is considerable. We have almost forgotten that Midleton was an event doubled in probability due to our alteration of the atmosphere, and undoubtedly Storm Chandra will show a similar contribution.
Storm Chandra was the culmination of an unusual sequence of events. Firstly, the intense cold of North America, caused by the southward displacement of the polar vortex, generated an extremely strong jet stream across the Atlantic. Speeds of 300kph were undoubtedly of benefit to some airline pilots travelling eastward, but also were capable of picking up and greatly intensifying nascent low pressure systems approaching Europe.
Secondly, Chandra was what meteorologists call a cyclonic bomb, deepening by more than 24 hectopascals (24hPa) in 24 hours. It also developed so quickly that models were quite unsure where it would be located until it was almost mature. Some placed it west of Ireland, some south – important considerations for how much moisture it would pick up, and how strong the winds would be.
Ultimately, it settled to the west and drove southeasterly winds up the Irish Sea (with temperatures at about 8-10 degrees Celsius) to further increase their rainfall capacity, dumping more than 100mm of rain in several locations on to already saturated ground. The duration of the rainfall was extended by the inability of the storm to progress eastward due to a large blocking anticyclone over northern Europe.
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It is now over 20 years since the first scenario-based projections of Ireland’s future climate were made. I led that project. Its key conclusion was that Ireland’s winters would become significantly wetter. Numerous studies have since confirmed this – and indeed Ireland’s annual rainfall has increased by 7 per cent since the 1961-90 period, with greater increases in winter.
[ Ireland must prepare itself for the ‘big flood’Opens in new window ]
More tellingly, recent work by my former colleagues in Icarus, Maynooth University, have indicated that the rainfall associated with a two-day event has increased in magnitude by nearly 12 per cent compared with a pre-industrial climate.
Extreme rainfall events are what we face increasingly in the future. Of course, whether such rainfall events occur on dry or already saturated ground is crucially important in terms of flood potential, and this is not something that is adequately considered in the calculations for flood-protection measures. Past rainfall data is often the basis for calculating the once-in-a-century rainfall event, but it is not safe to do so in a changed climate, and the concept is now obsolete.
Places that flooded infrequently in the past will now flood more frequently, and places that never flooded in the past may now become vulnerable. Clearly, an approach based on better warning and greater adaptation to what lies ahead is needed.
We either take the problem seriously and deliver what the law demands in mitigation and climate adaptation, or suffer the long-term lack of competitiveness in an economy stuck in short-term considerations
In other countries, the public can log in to their nearest river monitoring site. Information on the water level, and whether the river is rising or falling, is available in real time. When thresholds in the river level are reached, a text message is triggered to those downstream, warning of imminent flood, or alerting them to take immediate action to protect their properties.
A form of this exists in Ireland, but is based on participation by local authorities and opt-in by computer-savvy citizens. As such it is county-specific, of limited use to the residents of Bunclody or Enniscorthy, Co Wexford, if a flood threatening them is coming from Co Wicklow. But the technology needed is not rocket science.
As we sit in our cars and look at the maps showing the red roads that are traffic-congested, we are looking at mobile phones connected to transmission masts in that vicinity. Using the same technology to warn people in a specific catchment or sub-catchment is something that is an obvious next stage. After all, it is done in many of the world’s poorest countries, warning of impending floods or storms. It just takes joined-up thinking, and resourcing – in Ireland’s case between the Office of Public Works, Met Éireann and the Environmental Protection Agency.
[ Ireland needs a better strategy than ‘hope’ when it comes to flood preventionOpens in new window ]
In a disaster, the skeleton of society is laid bare. Politicians need scapegoats when their inability to make hard strategic decisions is exposed. Whether it be Met Éireann, the Habitats Directive, the freshwater pearl mussel, civil society groups, or local authority officials, blame has to be ascribed somewhere. But who rezoned the floodplains, who allowed housing closer to river banks than was wise, who has drastically underfunded climate-adaptation measures for the past 20 years?
The Central Bank recently estimated that floods are currently costing more than €100 million per year, with a loss of €500 million expected once every 25 years. That’s probably quite conservative, since the insurance bill for Storm Éowyn, which struck this time last year, is now in excess of €300 million.
A concern here would be that the willingness of the EU to come to our aid in future might be questionable, given our ambivalence towards meeting our legally binding climate obligations. While the EU has reduced its emissions by 40 per cent since 1990, Ireland has managed 5 per cent. The expression “cakeism”, ie having your cake and eating it, echoes Ireland’s recent interactions with the EU. Unfortunately, when it comes to climate change, the laws of physics don’t recognise this duality.
We either take the problem seriously and deliver what the law demands in mitigation and climate adaptation, or suffer the long-term lack of competitiveness in an economy stuck in short-term considerations, and tragically see more citizens left bereft of their homes and businesses as a consequence.
John Sweeney is emeritus professor in the department of Geography at Maynooth University
