EPA - Ireland's Environment 2016

Chapter 3: Climate Change

Impacts of Climate Change in the Marine Environment

Rising sea temperatures and sea levels, and ocean acidification have been identified as some of the key stressors

impacting on the state of the world’s oceans and coastal environments as a consequence of Climate Change (EPA,

2009; IPCC, 2014). These three factors have the potential to seriously affect the functioning of marine and coastal

ecosystems and biogeochemical cycles on global, regional and local scales (Gruber, 2011). These factors acting

independently, in combination, or synergistically, are likely to further impact ecosystems which have already been

stressed by other factors such as over fishing, chemical pollution and the introduction of alien species.

Temperature changes

Temperature plays an implicit role in many biological processes such as respiration, photosynthesis and remineralisation

as well as influencing, along with salinity, the density of seawater and ocean stratification. Over the period 1971–2010

the global sea surface temperatures (surface to 75 depth) has increased by 0.11˚C per decade (IPCC, 2013a). In Ireland,

while long-term temperature records are sparse, observations maintained by Met Eireann at Malin Head since 1958

show a progressive warming in the record since the 1990s of approximately 1ºC. This warming is partly explained by the

natural cycle of variability in the North Atlantic known as the ‘Atlantic Multi-decadal Oscillation’, but approximately half

of the recent warming is attributed to an underlying global warming trend (Dwyer, 2012).

Sea level changes

Global mean sea level has risen by 0.19 m over the period 1901–2010 (IPCC, 2013a). Rising sea levels in combination

with increased storm events that are also predicted to happen are likely to impact on many coastal habitats. An

average sea level rise of 0.5 to 1 m by the end of the century, in combination with storm surge events, could result

in approximately 300 to over 1,000 km

of coastal lands around Ireland being inundated by the sea (DeVoy, 2008).

A rise of 1 m in sea level would see 30% of existing wetlands disappearing (DeVoy, 2008). The habitats most at risk

include low-lying coastal lagoons, saltmarsh and estuaries, and of particular vulnerability are those that are prevented

from extending landward because of the presence of some fixed or artificial boundary. Many of the low-lying

estuarine sandflats, mudflats and lagoons found along the southeast coast, some of which have been identified as

Special Areas of Conservation (SACs), could be threatened. These habitats provide rich feeding grounds for a variety

of bird species as well as providing important nursery grounds for juvenile fish.

Coastal erosion

The 2013/2014 winter wave conditions that severely impacted the Atlantic coast of Europe were investigated and

demonstrated that this winter was the most energetic along most of the Atlantic coast of Europe since at least

1948. Storm wave conditions such as were encountered have the potential to dramatically change the equilibrium

state (beach gradient, coastal alignment, and near shore bar position) of beaches along the Atlantic coast of Europe.

One of the consequences of Climate Change will be more frequent and extreme storm events (EPA, 2010).

National Legislation and

Policy

Irish climate change policy takes significant step

forward in 2015.

The National Policy Statement on climate change (DECLG,

2014) articulates a vision to transition to a competitive,

low-carbon, climate-resilient and environmentally

sustainable economy by 2050; based on:

an aggregate reduction in CO

emissions of at

least 80% (relative to 1990 levels) by 2050 across

the electricity generation, built environment and

transport sectors

an approach to carbon neutrality in the agricultural

and land use sector.

The Climate Action and Low Carbon Development Act

2015 provides, inter alia, for approval of plans by the

Government in relation to climate change mitigation and

adaptation for the purpose of pursuing this transition and

meeting international obligations and targets to 2020 and

2030. Key provisions of the Act include:

the preparation and submission to Government for

approval of successive 5-yearly National Mitigation

Plans, which will specify the policy measures to reduce

GHG emissions in Ireland

the preparation of a National Adaptation Framework,

which will reduce the vulnerability of the State to the

negative effects of climate change and avail of any

positive effects that may occur; it will be reviewed

not less than once every 5 years, in keeping with the

continued development of the evidence base and

actions on adaptation and mitigation.