Reflections on Ireland’s Climate Change Assessment: Volume 1

Climate Science – Ireland in a changing world

Professor Brian Caulfield reflects on the first volume of Irish Ireland’s Climate Change Assessment with additional responses from Dr Karen Bacon and Professor Laurence Gill.

The Irish Climate Change Assessment (ICCA) report provides a comprehensive overview of our climate, the direction it is heading in and how adaptation and mitigation could change Ireland. The research effort is modelled on that produced by the Intergovernmental Panel on Climate Change (IPCC) and for the first time provides policymakers, academics, and the general public with a wealth of information on how our world is changing around us. But more importantly, the pathways to stop this change.

The research was funded by the EPA and included a writing team from Dublin City University (DCU), the Irish Centre for High-End Computing (ICHEC), Maynooth University (MU), Trinity College Dublin (TCD) and University College Cork (UCC). This comprehensive research activity is distilled into four volumes. The first volume examines the climate science and Ireland in a changing world, Volume 2 examines achieving climate neutrality by 2050, Volume 3 explores Ireland’s preparedness for our climate future, and finally, Volume 4 examines the benefits of transition and transformation. In this blog we explore the research presented in Volume 1.

The first volume of the ICCA explores the science of a changing climate in Ireland and beyond. The opening statement in this research unequivocally says that ‘we are already living in a changed climate’ and the best scientific estimates indicate that ‘global surface temperature increases from 1850–1900 to 2013–2022 is 1.14°C.’ The median annual precipitation over Ireland was up by 7% in the period 1991 to 2020 compared to the previous 30 years. Concentrations of methane and nitrous oxide in our atmosphere are at the highest levels they have been in 800,000 years.

But what does this mean for Ireland? The volume indicates that the average temperature has increased by 1°C since the early- twentieth century and that in recent decades we have experienced the warmest years on record since 1900. Increased incidence of extreme weather events as a result of human-induced climate change is also predicted in the volume. The evidence shows the link between human-induced climate change and the increased incidences of heat waves and extreme precipitation.

The report considers three climate scenarios for Ireland:

• Scenario One – Early Action: rapid global action occurs, and warming is limited to Paris agreement goals (below 2°C)
• Scenario Two – Middle Action: delayed global response and warming exceeds 2°C and continues into the next century
•  Scenario Three – Late Action: delayed and uncoordinated global response resulting in warming in excess of 3°C, which lasts beyond 2100

The analysis of the modelling suggests that early and rapid action would result in Ireland maintaining a climate that would be recognisable from what we have today. The authors warn that any delay in reducing emissions could result in Ireland having a climate that is ‘increasingly unrecognisable as the century progresses.’ Increased temperatures and a more frequent incidence of days with high levels of precipitation should be expected in Ireland if a global delayed response occurs. The research demonstrates that as sea levels continue to increase, storm surges can be expected around the island of Ireland. This could become extremely damaging to the critical infrastructure in cities like Cork, Dublin, and Limerick. We know from past events nationally and internationally that such damage can cost the state billions to repair.

The first volume of Ireland’s Climate Change Assessment provides a comprehensive overview of the probability of extreme weather events impacting upon Ireland, and beyond, should our climate goals go unrealised. Some elements of the report do not make for easy reading, given the potentially disastrous implications of a warming planet. These implications, the pathways to avoiding such disastrous impacts, and the benefits of a net zero Ireland are explored in the other volumes. The key recommendations coming from Volume 1 center around the urgent need to maintain and enhance our current climate observational systems in Ireland and to improve our modelling capabilities to enable scientists to predict under different scenarios how a changing planet could impact upon Ireland. The authors stress that this cannot be done in a silo and that greater cooperation with EU activities in this area are needed.

Professor Brian Caulfield

Response from Professor Laurence Gill

The Irish Climate Change Assessment (ICCA) report provides an overview of Ireland’s climate and the science behind assessing the ongoing changes. The report clearly shows that the climate is changing rapidly, linked to rising levels of industrialisation and global population, and that there has been an average temperature rise of 1°C since the early 20th century. From a hydrological perspective the projections for Ireland are for increased frequencies of high intensity (extreme) rainstorms which will cause more frequent and wider scale flooding in winter. The projections also suggest longer periods of drought in summer which could lead to pressures on our water resource infrastructure as well as challenges to the natural ecology rivers and wetland areas during low flow periods. In parallel, the projections are for the sea level to rise by over 0.3 m by the end of the century which will cause increased frequencies of storm surges as well as wider areas of flooding in the lower reaches of rivers areas caused by combinations of higher tides and more frequent extreme rainstorm events. These impacts are already being felt which should drive more urgent decarbonization policies and technologies, as well as more research and action into adaptation strategies.

Response from Dr Karen Bacon

Ireland’s changing climate is not in doubt. The Irish Climate Change Assessment report highlights that temperatures have risen by approximately 1 °C since 1850, concomitant with increases in extreme precipitation events. Mitigating the most severe effects requires rapid global action but further temperature increases are inevitable. A range of modelling estimates suggests that future temperature increases range from 2 °C, under rapid global action, to in excess of 3 °C under delayed and uncoordinated global action. This latter response is projected to result in a climate envelop for Ireland that is increasingly unrecognisable to that which we have today as the century progresses. The report highlights the need to enhance our current climate observation systems to be able to predict the impacts of changing climate on Ireland.

 

To read Ireland’s Climate Change Assessment in full visit the Environmental Protection Agency website

About the authors

Professor Brian Caulfield is Professor in Transportation in the Department of Civil, Structural and Environmental Engineering, Trinity College Dublin. He has been active in transport research for over 10 years and to date has attracted €8m in research funding from both National and EU funding sources. His research focuses upon the optimisation of transportation networks with the goal of reducing emissions and meeting our climate change targets.

Professor Laurence Gill is a Professor in Environmental Engineering in the School of Engineering, Trinity College Dublin. His research interests involve studying the fate and transport of both air and water-borne pollutants in the natural and built environment, the development of passive treatment processes, the ecohydrology and greenhouse emissions of wetlands and the characterisation of karst hydrological catchments.

Dr Karen L. Bacon is a plant ecologist and palaeoecologist in the School of Natural Sciences at the National University of Ireland, Galway. She completed her PhD in plant palaeoecology in 2012 in University College Dublin. She then spend several years as a lecturer in the University of Leeds before returning to Ireland in 2019. Dr Bacon’s interests span palaeobotany to modern plant ecology and incorporates elements of plant biology, geology and chemistry.

The views expressed within this blog are those of the authors and do not necessarily reflect the views of their employers or of the Royal Irish Academy.

About the blog series

In January 2024 the Environmental Protection Agency published Ireland’s Climate Change Assessment (ICCA), a comprehensive and authoritative assessment of the state of knowledge around all key aspects of climate change, with a central focus on Ireland. The report provides an assessment of our understanding of climate change, tying together all available lines of evidence to provide actionable information.

The Royal Irish Academy’s Climate Change and Environmental Science Committee recognises that it has a role to play in communication and advocacy for climate action in Ireland. Through a four-part blog series the committee aims to distil and offer perspectives on each of the four ICCA volumes with the goal of highlighting the importance of their content and promoting and sustaining a discussion around the topics addressed.

Read the next blog in the series here.