Climate change is one of the biggest threats to the Gower landscape and we are already feeling its effects. It is widely accepted that human behaviour is the dominant cause of climate change, a result of our increasing emissions of greenhouse gases such as carbon dioxide (CO2). Despite efforts to reduce carbon emissions, Gower will still feel the effects of inevitable climate change as a result of past emissions locked in the atmosphere. Adaptation to these changes is essential to preserve the special qualities of the area.
Climate change is already having an impact on Gower. Increases in temperature have been recorded over the last 40 years: in their research, Mayes and Powell record that mean daily maximum and minimum daily temperatures on Gower increased by 0.7 and 0.9 degrees centigrade respectively between the periods 1962- 80 and 1981- 2000. This same research has also demonstrated that winters have become warmer, wetter and more unsettled.
Unsettled weather can have a significant impact on the landscape, as was the case at the beginning of 2014 when winter storms caused several years worth of erosion damage in just a few weeks. At Rhossili, one of the most famous beaches in Wales, relentless rain and stormy weather washed away the main access path to the beach. The path was not due for major refurbishment for a further ten years. However, the storm brought this work forward and the new path is designed to be more resilient to extreme weather events in future.
How the climate might change in the future
It is predicted that climate change will impact on all areas of the built and natural environment of Wales within the next 50 years. Some of the changes could benefit Gower, but many could have disastrous consequences. For example, warmer summers and milder winters could increase tourism and the length of visitor stays. However, changes in temperature could impact on local farmers, as it may alter the growing seasons and change the types of crops that can be grown on Gower.
Another catastrophic impact is the predicted sea-level rise together with more frequent, less predictable storm events, which could cause the coast of Gower to change quite dramatically. The area of Gower facing the greatest threat from these pressures will be the sensitive estuarine environment of North Gower. The ecosystems of the estuary are relatively fragile. Marshes, including Llanrhidian Marsh, an internationally important site for waders and wildfowl, are threatened by climate change in many ways. Warmer summers may cause increased evaporation and drought, leading to increased salinity (‘saltiness’), which in turn causes changes in plant communities, including a loss of vegetation. Grass species can become more competitive because they are more likely to survive in such conditions than many of the more ecologically valuable species.
Increased rainfall and storm events can result in an increase in pollution run off. This can lead to an increase in nutrients and toxins in the marshes, again altering the vegetation mix of the habitats. Inundation and waterlogging caused by sea level rises and storms can lead to more exposed mud, providing opportunities for invasive species to colonise the marshes as well as causing erosion and changes in soil processes – all of which can reduce the amount of habitat for existing wildlife.
Marshes are also at risk of ‘coastal squeeze’, where sea level rises and human development, such as flood defences, cause a reduction in the size of habitats. This can have significant consequences for species that rely upon the habitats under pressure – especially in marshes, which are relatively rare both nationally and internationally and so their loss cannot easily be compensated for elsewhere.
Whilst some habitats can ‘retreat’ inland when sea levels rise, others are blocked by sea cliffs or dunes and this means they become ‘squeezed’ even further – reducing in size and eventually disappearing altogether.
There will be several impacts of climate change in Gower, as identified by the UK Climate Projections:
- The number of very hot days, especially in summer and autumn, is set to rise.
- There will be fewer very cold days in winter.
- Winters will be wetter and summers are predicted to become drier.
- There will be more frequent storm events.
- There will be more contrast between seasons.
- There will be much less snowfall.
- Growing seasons will be longer.
- At sea, surface water temperatures will increase around the coast.
- The sea level will rise from 1990 levels by 30 to 43 cm by the 2080s.
Sand dunes, such as those at Nicholaston Burrows, are also at risk from climate change. Weather patterns that bring both stormy and flat seas can alter the patterns of sediment supply and removal, which are necessary for the formation of dunes. Increasingly energetic seas can increase the rate of dune erosion. Drier summers can lead to a rise in wind-blown sand, causing dunes to grow in size and extent; whilst wetter winters result in wet sand that is less mobile, which can affect dune processes and vegetation.
As you can see, the impacts of climate change on Gower are many and often complex! It’s therefore important that we continue to study how the climate is changing and do our best to minimise its harmful effects by helping to make the landscape more resilient, whilst also modifying our own behaviour.