How will Climate Change affect Wales?
The main ways that climate change will affect Wales over the coming century is by impacting on average temperatures, rainfall, extreme weather events, and flooding. The chart below, published by the Welsh government, shows some of the main projected impacts from climate change in Wales for a medium emissions scenario.
On the other hand, extreme heat waves of over 40C are also more likely. The latest report suggests that close to half of all over 65's in Wales are already vulnerable to heat exposure [1]. On 18th and 19th July last year (2022) for example, Wales and the UK experienced record breaking heatwaves, with temperatures in some parts of the UK hitting over 40C.
The heatwaves led to widespread suffering, with care services for the elderly placed under stress, a surge in emergency calls and hospitalisations, and estimates of the number of deaths close to 1,000 [2]. A study suggested that heatwaves like this, though still rare, were ten times more likely now with climate change. The author of the study, Dr Mariam Zachariah, said:
“The maximum day-time temperature on 19 July was so extreme that it was a rare 1-in-1,000-year event, even in the current climate. The likelihood of the average temperature over the two days was also rare, with a 1 in 100 chance… these temperatures would have been statistically impossible in a world before the Industrial Revolution."
Flooding
Sea levels around the coast of Wales are expected to rise between 0.5m and 1m this century due to global warming. As a result of changes in rainfall, sea level rise and the greater frequency and intensity of extreme rainfall events, over 10% of the land area in Wales is at risk of flooding over the coming decades as a result of climate change. That is a huge land area. The risk of flooding due to climate change is severe enough that the Welsh parliament has incorporated the latest projections into its national planning policy, to ensure that no more developments take place on land that is at risk of flooding due to climate change [3].
To get some idea of how this impacts on the Welsh coastline, the pictures below show in red the areas of the Welsh coast that will be under the annual flood level by 2050 [4]. This does not mean they will be permanently under water, it means they will be at higher risk of annual flooding.
So overall, due to global warming Wales will likely see drastic changes to its coastal cities, towns and villages this century. Many of its beaches are likely to be underwater. Summers will be 5C hotter and much drier, winters will be warmer and wetter, and there will be a lot more extreme heavy rainfall and heatwave events.
[1] https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(18)32594-7/fulltext (for a CNN report see https://edition.cnn.com/2018/11/28/health/global-climate-change-and-health-report-intl/index.html)
[2] https://www.imperial.ac.uk/news/238772/climate-change-made-uk-heatwave-more/
The table shows significant increases in temperature during the winter and summer, but especially in the summer, with a huge 5C increase in daily summer temperatures by 2080, coupled with a decrease in summer rainfall by one fifth. Winter temperatures also rise, as do the levels of rainfall. On the whole, there is a clear pattern of hotter and drier summers and milder and wetter winters.
We can already see this happening. The image below shows the distribution of the hottest and coldest years on record over the last century. We can clearly see that we are already experiencing significantly warmer temperatures.
Although this will affect crops and the types of crops we are and aren't able to grow, overall it does not sound so bad, and some people may even welcome the change as it looks as though the weather will be better. There are, however, additional factors that arise from this change in the weather that make climate change much more of a threat and that aren't considered above.
Extreme Weather Events
One of those factors is a greater frequency and intensity of extreme weather events. Professor Ian Hall, head of Cardiff University's school of earth and environmental science, for example, says that the 'intensity and frequency' of extreme weather events in Wales 'is likely to increase as global warming continues'. This means that there will be an increase in the frequency and severity of, for example, heatwaves, torrential rain, and storms and gales.
Storms Ciara, Dennis and Jorge in early 2020, for example, led to record rainfall and river flows across Wales and the most widespread flooding seen since 1979. These are exactly the kind of extreme weather events that will become more common due to climate change, with even the Royal Meteorological Society describing them as a 'taste of things to come' for Wales.
But it is not just Welsh scientists and national scientific institutions saying this. The figure below sums up the science that has been done all over the world, and shows how the frequency and intensity of extreme rainfall events will change as a result of climate change. It's important to note that the figure does not show how average rainfall patterns will change, but how the frequency and intensity of extreme rainfall events will change. The more dark blue the area, the greater the frequency and intensity of extreme rainfall events.
It is clear from the figure that Wales and the UK are situated within a band of medium blue that stretches across the Atlantic and over Scandinavia, and which means we will see a roughly 30% increase in extreme rainfall events during this century.
