Climate Resilient Coastlines, UK

Abstract

Climate change has taken its toll on the UK coastline through increased sea levels, increased rate of erosion and heightened flood frequency and intensity. This has had detrimental impacts on people and the economy through the destruction and damage of infrastructure. With global mean temperatures still predicted to increase, the UK coastline is more than likely to experience further destruction if effective steps are not tafken to strengthen the resilience of coastal infrastructure. This article explores how the UK can ensure climate resilience through management and structural adaptation, which will enable the infrastructure sector to become prepared and adapt to the changes in climate they are yet to face.

Keywords

UK, CLIMATE CHANGE, CLIMATE RESILIENCE, SEA LEVEL RISE, COASTAL FLOODING, EROSION, INFRASTRUCTURE

Introduction

Over centuries, the Earth has experienced climate change, which results in a significant shift in global air temperatures, leading to a much warmer or colder climate across the globe. Currently, the Earth is going through a warming stage and atmospheric temperatures have risen by approximately 1˚C (Allen at el., 2018), with further increase predicted. The increase in global temperatures has led to extreme weather events and created many issues for the environment.

Climate change has impacted the Earth in a range of ways, from melting arctic ice and increasing sea levels, to reducing annual precipitation rates even further in arid regions and increasing rainfall in regions like the UK, which has led to several storm and flood events in recent years.

One of the most vulnerable areas to climate change within the UK is its coastlines. For years, the UK’s coasts have fallen victim to the severe impacts of climate change and sea level rise, imposing serious issues for the environment and people of these areas. This report will outline the impact that climate change has had on the UK coastline and how the UK can develop and protect infrastructure to create a climate resilient coastline.

Climate Change in the UK

In recent years, the UK has witnessed drastic changes in weather patterns and harsher seasonal changes due to climate change. These changes have been quantified using the UK Climate Projections (UKCP) tool, which provides the most up-to-date findings on UK climate change and forecasts. Observations carried out in the UK have found a general warming trend, which shows that temperatures within the UK are increasing and are expected to continue to increase as global temperatures rise (UKCP, 2018). The decade between 2008-2017 was found to be an average of 0.3˚C warmer than 1981-2010 and 0.8˚C warmer than 1961-1990. Also, the ten warmest years the UK has experienced have all occurred after 2002 (Met Office, 2019), whereas the ten coldest years were all prior to 1963. Figure 1 clearly displays the change in temperature within the UK, especially in the last 3 decades (1990-2020) which have gotten considerably warmer than previous years.

Figure 1: UK annual air temperature with the 5 coolest and warmest years highlighted (Met Office, 2019)

Analysis of the England Wales Precipitation (EWP) series has found that the UK can expect to have drier summers and wetter winters (Gregory et al., 1991 and Kendon et al., 2017). This has been further supported by regional model projections for the coming decades (Maisey et al., 2018). However, Murphy et al.’s (2020) research has found discrepancies with this widely reported trend and believe further research needs to be carried out in order to better understand the seasonal change in precipitation within the UK, by re-evaluating early data and trends.

The UK has also experienced a significant rise in sea levels. An observational study carried out by Woodworth et al. (2009), found that the sea level rise the UK has experienced as a results of climate change ranges from 1.44 +/- 0.2mm per year. Similar results were recorded by Haigh et al. (2009) when investigating sea level rise within the English Channel.

Impact on coastal cities

The changes the UK has faced as a result of climate change has made the coastal regions amongst the most effected areas. The coastlines are more susceptible to storms, sea level rise and are being directly impacted. Research suggests that the UK coastlines can expect to see an increase in flood risk under all emission pathways scenarios due to the increase in mean sea levels. It has been noted that flood activity and sea levels can be impacted by a change in atmospheric storminess, which has the potential to increase sea levels (Horsburgh et al. 2020). However, the increase in flood activity appears to be a result of increased sea levels rather than a change in atmospheric storminess and storm surges (UKCP18, 2019). There appears to be little to no evidence suggesting that storm surge magnitude has changed (IPCC, 2012), which means the increase in sea level cannot be accounted to this either.

Several different regions within the UK have been severely affected by coastal flooding over the past few years. One example of this is Torbay, which is located in the south of England and includes three towns, Torquay, Paignton and Brixham. Torbay has been flooded as a result of several different sources, such as overflowing of rivers due to intense rainfall, sewer flooding, highway flooding and flooding due to sea defence breaches. Within this region, sea level rise is predicted to rise by over 1m over a 100-year period, putting several properties and other infrastructure at serious risk of flooding (Torbay Council, 2016).

Coastal areas are often subjected to a high degree of change as a result of natural processes, such as erosion. Coastal erosion is a complex process which is caused by a variety of sources, with sea level rise being one of them. Even with regular sea-levels, the coast is naturally inclined to move landward overtime. However, with the sea level rise that the UK is currently experiencing, the rate of erosion has increased considerably. The east coast of England is the most vulnerable to erosion due to the coastal geomorphology of this region, which allows for it to be easily eroded (Burden et al., 2020). In recent years, the storm events that had occurred in different coastal regions (Storm Eleanor 2018 and winter 2013/14) had led to flooding and an increase in coastal erosion. The impact of such events often leads to a sudden spike in flooding and erosion impact costs. For example, the damage incurred to the Dawlish Railway line during the series of storm events over the winter of 2013/14, was estimated to be between £60 million and £1.2 billion (DMF, 2014).

The impact of climate change has been detrimental for several different sectors (Table 1), as there are often many issues arising due to different aspects of climate change (sea level rise, precipitation, etc…). As a result of this, effective management of coastal infrastructure has become more important than ever.

Table 1: Illustrative impacts of climate change on different sectors (OECD, 2018)

From this we can see that the UK coastline is being severely impacted by climate change due to a rise in sea levels, flood events and an increase in coastal erosion rates. This has already started to have detrimental effects on communities, the environment and on infrastructure. Climate change has inflicted hundreds of million pounds worth of damage upon the UK coastlines and is an issue that needs to be managed to prevent further destruction.

The UK’s Response

The UK is aware of the urgent need to respond to the threats that are being imposed on their coastlines as a result of climate change, with the biggest threats being sea level rise, increased flood events and coastal erosion. The Environment Agency (2015) has predicted that over 700 properties could be at risk of being lost to erosion and that there are 247,000 businesses and properties at high risk of flooding. Coastal response and management within the UK must be conducted at a regional or local level. The reason for this being, coastal areas respond differently to the impact of climate change due to site specific factors (Masselink et al., 2020). Site specific factors must me considered throughout the development and planning process of creating climate resilient coastlines.

Due to climate change, the infrastructure within these coastal cities is often subjected to a considerable amount of damage. Damage to certain sectors (Figure 1) leads to wide-spread disruptions and can affect hundreds of thousands of people. Furthermore, the damage caused can become very costly and places a huge strain on organisations and on the economy. Therefore, in order to minimise the impact of climate change on infrastructure, the UK must develop climate resilient infrastructure. The idea of climate resilient infrastructure is to ensure that it is built, designed and planned in a way which is prepared for and adapts to changing climate conditions (OECD, 2019). This can be achieved through both structural and management adaptation.

For several years, coastal areas have been protected and managed by different hard and soft engineering methods. Hard engineering methods compromise built structures, which aim to prevent retreat and protect the coast from flooding events. Although hard engineering methods have been widely used across the UK, this approach is being reconsidered due to some of the implications that have arisen as a result. Many of these structures result in what is known as beach lowering, which increases wave action and undermines the defence as it promotes coastal erosion. As a result, many of these structures have been deemed as unsustainable, which has led to an increase in soft engineering methods to recreate natural coastlines.

The use of soft engineering and adaptation has been demonstrated well by some of the work carried out by the National Trust who have put in place a Shifting Shores scheme, which aims to adapt the coast in order to work with nature, in the hopes of providing more effective protection for habitats and infrastructure (National Trust, 2020). Part of this is done by ‘rolling back’, which involves creating enough space for the coast to naturally retreat by relocating infrastructure and saving it from the impact of sea level rise, flooding and erosion. By 2030, the National Trust aims to have established 80 adaptation strategies across the UK. This scheme has seen several areas of improvement across UK coasts. The coast of east Sussex is currently reviewing architectural plans in order to roll back in advance to prevent future damage to infrastructure (National Trust, 2015). As a result of this scheme, the Welsh coast’s footpaths have also been reinstated after being damaged by the 2013/14 winter storms. However, the chance of being able to roll back to protect this further in a timely manner appears to be unlikely, as certain sections have already failed due to coastal erosion.

Climate resilient infrastructure can also be developed through policy and management. Adaptation Reporting Power has been introduced under the Climate Change Act (2008), which provides the government with the power to request reports from reporting authorities in order to see how and what they are doing to adapt to climate change. These reporting authorities include organisations who are responsible for infrastructural services. This is a good method to ensure organisations are considering the potential risks of climate change on infrastructure and enables them to plan and respond to these issues in a timely manner. Although this could be a beneficial approach in managing UK coastal infrastructure, it is not a mandatory task for organisations anymore. The government only mad the first round of reporting mandatory and since then it is being used on a voluntary basis. This may not be an effective approach as many organisations may opt to not report on their adaptation and risk strategy, prompting them to not consider the detrimental impacts on climate change on coastal infrastructure.

Several studies have been conducted within the UK that display how effective the use of modelling could be in promoting climate resilient infrastructure. For example, a study conducted by Chen et al. (2018) investigated how the use of the EU-CIRCLE framework (Figure 2) and high-performance flood modelling will enable stakeholders to better understand the future impact of flooding under a range of scenarios. They were able to use the framework and modelling to illustrate the impact of past flood scenarios on critical infrastructure, provided by Torbay Council, and the implications this had on the town from the disruptions caused by the flood events. This information is very important in developing adaptation measures and enhancing the resilience of infrastructure within the region.

Figure 2: EU CIRCLE resilience framework (EU CIRCLE, 2015)

Conclusion

The UK coastlines will continue to become even more vulnerable overtime as a result of climate change and sea level rise. This has put many coastal regions within the UK at serious risk of flooding, erosion, which inflicts damage and loss of infrastructure and disrupts the operations of entire populations. As a result, the UK needs to create an urgent response system which better manages the infrastructure of coastal areas. Several different pieces of research suggest that the best method for ensuring infrastructure resilience is through adaptation, whether that is structural adaptation or management adaptation.

In recent years, natural forms of defence are encouraged as they work harmoniously with the idea of allowing the coast to adapt rather than attempting to halt and deter the impact of flooding and erosion. This approach coupled with management adaptation, which is focused on promoting timely intervention, could prove to be a very beneficial approach for infrastructure resilience within the UK. Infrastructure management can be encouraged and supported by local governments through policy and framework, which is made lawful to follow for infrastructural services. This could be a useful method in encouraging infrastructural services to consider the impact of climate change on coastal infrastructure and prompt them to develop an adaptational strategy, which will strengthen infrastructure resilience.

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