In identifying climate risk, it is important to realise that risk is based on projections and therefore requires regular updating. The main climate related risks are outlined below and the following is an account of possible effects on key operational areas of the Local Authority as set out in the Local Authority Adaptation Development Guidelines [11]. In terms of assessing how such events affect operational areas of Cork County Council, some examples are included.

out in the Local Authority Adaptation Development Guidelines [11]. In terms of assessing how such events affect operational areas of Cork County Council, some examples are included.

Based on available sources, observed and projected changes in seven climate variables have been investigated. They are summarised below, with future climate risks identified:

Observed The analysis of river flows is complex and subject to large variability and as a result, it is difficult to identify impacts of climate change. For Ireland during the period 1954 to 2008, summer mean flows were dominated by decreasing trends, while for winter there is a tendency for increases in mean flows. Annual and winter high flows are also dominated by increasing trends [31].

Projected Changes in temperature and precipitation will affect hydrological response. Due to the uncertainties associated with projected changes in precipitation, projected changes in hydrological response remain subject to a high level of uncertainty. The response of individual catchments will be determined by individual catchment characteristics (e.g. groundwater versus surface water dominated catchments). For example, summer reductions for groundwater dominated catchments are not as severe as those projected for surface water dominated catchments [32]. Using runoff impact models a robust indication of increasing seasonality in hydrological regimes is evident with increases in winter and spring stream flow likely and a decrease in summer. A 20% increase in the amount of water flowing during winters through rivers are expected for the majority of catchment by mid-late century while for summer, decreases of over 40% (those with little groundwater storage in particular) have been simulated for the end of the century [32][33]. Projected increases in winter flows coupled with likely increases in extreme precipitation events are likely to lead to an increased flood risk. However, catchment response time will be critical in determining the changing nature of extremes and catchments with fast response times are likely to be most at risk.

Drier summers could have effects on summer base-flows of rivers in Cork and recharge of underlying aquifers. This ultimately has implications for the provision of drinking water as was evident in many parts of the county during the prolonged drought period in Summer 2018.