Earlier this week the Environment Secretary Michael Gove announced the publication of the UK Climate Projections 2018 (UKCP18). UKCP18 represents the most up-to-date assessment of how the climate of the UK may change over the 21st century and the first major update of UK climate projections in nearly 10 years.
Climate change is an important consideration for marine stakeholders including coastal zone managers, port and shipping operators, owners of offshore renewable energy infrastructure and coastal landowners. The past few years have given us a glimpse of what the future may hold, with the UK experiencing a number of extreme weather events: successive storms meant that winter 2013/14 was the wettest in the Met Office’s records whilst the summer of 2018 was the joint hottest ever recorded in England. This pattern is anticipated to continue.
Some of the most pronounced effects of climate change are likely to be rising sea levels and changing weather patterns which may result in increased flooding and accelerated coastal erosion. The Earth is already locked in to sea level rise for decades and centuries ahead and by 2100, sea levels around the UK are expected to have risen by between approximately 0.3 and 1.2 metres above the 1981-2000 average level.
We have identified five key points in the UKCP18 from a coastal perspective:
1: UK coastal flood risk is expected to increase over the 21st century and beyond under all future emission scenarios considered. However, there are large regional differences in projections of future mean sea level.
2: The UKCP18 sea level projections are consistently larger than in the previous set of UK climate projections (UKCP09) for similar emissions scenarios.
3: UKCP18 now provides some exploratory projections of mean sea level out to 2300. (UKCP09 only considered to 2100). Based on these results, sea levels continue to increase beyond 2100 even with large reductions in greenhouse gas emissions.
4: UKCP18 finds no evidence for significant changes in future storm surges.
5: The annual maximum significant wave height is projected to change by up to +/- 1m or 20% by the end of the 21st century: increases are found to occur off the south west of the UK, in parts of the Irish Sea and to the north of the UK but reductions are seen off the west of Ireland and in the southern North Sea. However, uncertainty with projections is high.
Whilst projections of change for time horizons towards the end of the 21st century may appear to lack immediate relevance, this is not the case. For instance, infrastructure assets such as sea defences typically have design lives measured in many decades and so consideration of long term change is critical in order to build in climate resilience.
Having access to reliable climate change predictions and understanding how best to apply them is therefore essential for informed decision making. This will become ever more important if, as anticipated, the rates of change accelerate throughout the 21st Century.
View the UKCP18 Science Overview Report, visit: https://www.metoffice.gov.uk/pub/data/weather/uk/ukcp18/science-reports/UKCP18-Overview-report.pdf
Prepared by Tony Brooks, Marine Physical Processes Specialist.
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