The Dublin Region is faced with many climate change related risks and challenges, from flooding and sea level rise, to air pollution and extreme weather events.
The effects of urbanisation and climate change both impact and increase the risk of flooding. This is the case for Dublin, as it is a coastal county and has a complex system of rivers, canals, surface-water sewers, foul sewers and urban watercourses. Flooding can have multiple causes, including sea level rise, run-off water, heavy rainfall, extreme events, storms and tidal surges. Over the last 10 years in particular, the number of flood events caused by extreme weather have increased at a significant rate. Furthermore, it is predicted that the probability of these flood events occurring will increase, i.e. a 1-in-100-year event can become a 1-in-25-year event instead. The number of heavy rainfall days per year is also projected to rise, resulting in a greater risk of both fluvial and pluvial flooding.
Dublin is especially vulnerable to future risks, due to the projected population growth over the coming years. This increased risk of flooding will affect the region’s already vulnerable systems, in terms of increased pressure on water and sanitation systems, and damage to critical infrastructure and property.
Sea Level Rise
As a coastal region, Dublin is also faces significant risk of sea level rise, and this would have significant impacts on the county and its infrastructure. Following recent extreme flood events and predictions of sea level rise due to climate change, Dublin City Council carried out a review of the capacity of the existing coastal flood defences to provide protection for urban areas. Dublin City Council calculates that over the last 15 years, the Average Annual Sea Level in Dublin Bay appears to be rising faster than initially projected. The recorded average sea level rise in Dublin Bay for the period between 2000 and 2016 was 6-7 mm per year, compared to a projected rise of 3-4 mm per year globally. This, coupled with increased wave heights, tides and frequency of coastal storms, storm surges, means that coastal communities will face increased economic, social and environmental vulnerabilities if we don’t act now.
Extreme Weather Events
Dublin has experienced an increase in extreme weather events, and their effects can be seen in prolonged periods of extreme cold or heat, which cause snows and heat waves, hurricane gusts due to violent winds, and heavy rainfall resulting in flooding. Recent weather events such as Storms Ali, Bronagh and Ophelia, the Beast from the East and the heat wave during the summer of 2018 all put local and national infrastructure at risk, such as electricity and water supplies. Met Éireann predicts that we will experience wetter and milder winters, with a 10-15% increase in rainfall, and drier summers. It is also projected that extreme wind speeds will increase during the winter periods. This would greatly affect critical infrastructure such as communication and transportation, which may be disrupted by the violent winds. Also, this increase in extreme wind events, coupled with sea level rise and coastal storms, may lead to increased wave heights and could result in habitat loss and damage, due to coastal and soil erosion.
Dublin’s emissions from the transport sector, construction industry and the burning of waste and emissions from industrial activities, all make the region vulnerable to pollutants.
Air pollution and air quality risks mainly relate to health and risks to ecosystems.
These risks may be further exacerbated in the future, especially with a projected population growth that will require more services such as transport networks, energy, waste disposal and housing. Emissions of air pollutants, particularly PM10 (particulate matter) and NOX (nitrogen oxide) from road traffic, remain the biggest threat to air quality in urban areas. Even though the new standards for car emissions have resulted in cleaner fuels and reduced emissions, Ireland has still seen an increase in both the number of cars and their engine sizes. Also, there has been a shift to diesel engines in recent years, which are lower in CO2 but are higher in particulate matter. Dublin has had an increase in construction and development over the recent years, and construction is projected to grow with the increased demand for housing from a growing population. As construction and demolition in the region increases, so do airborne emissions and dust particles, which further aggravate health issues in the population.