Changing Climatic Conditions of British Sporting Events under Increased Global Temperatures

While this phrase has become somewhat of a mantra for some people in the climate science community, the effects of increased global temperatures on the climate of the UK are expected to be much more nuanced than can be conveyed in just six words.  

This nuance continues to be well researched by scientists and there has been recent work aiming to convey this complexity in ways which are relatable to the British public. Some examples of this include work by scientists at the Met Office to produce a set of Future Forecasts to explore how Wimbledon and Glastonbury Festival may be affected by a heatwave in the 2050s. Similarly, BBC Sport’s Sport 2050 looked at how the weather could impact sporting events across the world by 2050.  

Expected future climatic conditions of popular UK sporting events 

In this blog we look at a recent piece of work conducted at the Met Office which aims to build on these previous studies and explore the expected future climatic conditions of a number of popular sporting events spread across the country and throughout the year. These include the Great North Run (Newcastle in September), the first Test match at Edgbaston (Birmingham in June), the London Marathon (London in April) and the start of the Six Nations (February) at the Twickenham (London), Murrayfield (Edinburgh) and Principality (Cardiff) stadiums.  

By exploring this range of events, which also includes a range of cultural and social events, this work aims to build a richer picture of the future climate and highlight changes to the climatology of events which take place outside of the British summer – the season which has been the focus of previous similar studies. 

The above events were chosen due to their significance to large portions of the British public and, because they are outside, our experience of them is closely linked to the weather conditions at the time. Understanding changes to the climate of these events will give an insight into one way in which people’s daily experiences and lifestyles are likely to be different because of climate change. 

How the study was carried out 

For the analysis of this work, the dates the chosen events took place on over the last 20 years were used to create a window of plausible dates for the event (assuming the organisers continue with these timings). To understand the historic observed climate of the events, HadUK-Grid data (at 12km resolution) was used, and the 1980-2010 time frame was selected to form the baseline period. For the future projections, bias corrected UKCP18 Regional data (12km resolution) was used covering 2040-2060. The analysis uses all 12 of the ensemble members available to explore the full range of uncertainty available within the UKCP18 Regional data. The projections data models a high emission (RCP8.5) future. 

Key results and common themes 

Let’s begin by having an overall look at the results from across all the events analysed. Although the events are spread across all four seasons, some common trends can be seen. The three plots in Figure 1 compare the average values from observations with the average values from future projections for maximum daily temperature, minimum daily temperature, and daily rainfall, respectively. Each of the colourful dots represents one of the twelve ensemble members which make up the UKCP18 Regional projections. 

Plot 1: Average maximum daily temperature 

Plot 2: Average minimum daily temperature  

Plot 3: Average daily rainfall.

Figure 1: Dot plots comparing the observed average and the projected future average (from 12 ensemble members) for each event for three climate metrics: maximum daily temperature (Plot1), minimum daily temperature (Plot 2) and daily rainfall (Plot 3). The labels on the horizontal axis correspond to the events as follows: Great North Run (GNR), the first Test match at Edgbaston (ETM), the London Marathon (LM) and the start of the Six Nations at Murrayfield (M6N), Principality (P6N) and Twickenham (T6N).  

In Plot 1, average maximum daily temperature, we see that across all the events, the observed average maximum daily temperature (the average value of the highest temperature recorded each day in the grid squares surrounding the event location) is either less than or at the very lower end of the projected future values for this metric. This means that it is likely, under this high emission scenario, that the peak temperatures for these events in the 2050s will be higher than those we are used to. While this may not be an unwelcome change for rugby fans spectating at the Six Nations, these increases may make for an unpleasant experience for the masses taking part in the Great North Run and London Marathon. 

In Plot 2, minimum daily temperature, a similar, but more pronounced, trend is evident when we look at the average minimum daily temperature. This time for all events the average observed minimum temperature is cooler than those projected by all the ensemble members. This shows that we can expect to see increases in the daily minimum temperature for all the events, no matter the season. In some cases, the difference between the coolest projected average and the observations is over 1 degree and in the case of the Great North Run this difference is over 2 degrees. 

The average rainfall shown in Plot 3,  presents a much more varied picture, this reflects the high natural variability of rainfall in the UK. It is only at Twickenham and Principality during the Six Nations where the average observed rainfall between 1980 and 2010 does not fall in the range of the projected rainfall for the 2050s. Despite these both being part of the Six Nations and hence taking place at the same time, the data projects conditions will become drier on average at the home of Welsh Rugby while its English counterpart can expect wetter conditions on average. For the first Test at Edgbaston and for Murrayfield during the Six Nations, there is no clear change in the average daily rainfall evident in the data as some ensemble members project more rainfall while others project less than is historically observed.  

How might extreme conditions affect our collective experiences of the sports we love? 

While these average values reveal some interesting results, they tell us little about the more extreme weather we may encounter. Often it is these extreme conditions which are likely to seriously affect our collective experience of these events.  

To explore this further, we will look at the 5^th and 95^th percentile values for the daily maximum temperature and daily precipitation for some of the events, again comparing the values from observations with those from the projections (taking the median of the 5^th or 95^th percentile values from all the individual ensemble members).  

Maximum daily temperatures 

Table 1 below, shows that the expected increases in the 5^th percentile values across the events varies from 1.5°C to 2.6°C and for the 95^th percentile the increases range from 0.5°C to 1.7°C. Regarding maximum daily temperatures, it is likely to be these more extreme high-end temperatures which are of interest to people participating in the chosen sporting events. The largest increase of 1.7°C in the 95^th percentile value is for the London Marathon, and with tens of thousands of people pushing their bodies to complete the marathon, this increased chance of experiencing temperatures over 22.3°C will only add to the challenge.  

This is likely to cause concern for organisers as they work to ensure the safety of the participants in increased temperatures and face challenges like running out of water at the water stations as happened when high temperatures were recorded during the 2018 London Marathon. It may also mean we are less likely to see some of the weird and wonderful fancy dress we have become accustomed to as participants get advised to consider the safety of their costumes in higher temperatures (see above linked article). 

	Daily maximum temperature (°C)
	Observation		Projection		Change
	5th  Percentile	95th  Percentile	5th  Percentile	95th  Percentile	5th  Percentile	95th  Percentile
Great North Run	13.6	21.8	16.1	23.0	+2.5	+1.2
Edgebaston first Test	13.3	25.1	14.9	26.2	+1.6	+1,1
London Marathon	9.0	20.6	10.5	22.3	+1.5	+1.7
Six Nations Murrayfield	1.7	11.1	4.0	12.1	+2.3	+1.0
Six Nations Principality	2.0	11.9	4.6	12,7	+2.6	+0.8
Six Nations Twickenham	1.9	13.1	3.8	13.6	+1.9	+0.5

Table 1: Table comparing values from observation and projections for the 5^th and 95^th percentiles of daily maximum temperature for each of the sporting events chosen.  

Daily Rainfall  

The largest change in the 95^th percentile value, representing the more extreme rainfall, is seen in Table 2 below, to be at the Six Nations at Principality.  Here there is projected to be a significant decrease of 5mm from 16.3mm to 11.3mm. This reduction in volume of rainfall expected on more extreme rainfall days may make many people’s experiences of watching the Six Nations more pleasant and may also make the groundsmen less concerned about their pitches flooding.  

	Daily rainfall 95th percentile/mmtemperature (°C)
	Observation	Projection	Change
Great North Run	10.7	5.8	-4.9
Edgebaston first Test	12.2	9.7	-2.5
London Marathon	6.7	6.6	-0.1
Six Nations Murrayfield	10.2	9.9	-0.3
Six Nations Principality	16.3	11.3	-5.0
Six Nations Twickenham	7.4	8.3	+0.9

Table 2: Table comparing values from observation and projections for the 95^th percentiles of daily rainfall for each of the sporting events chosen. For both observations and projections, all events had a 5^th percentile value of 0.0 mm. 

Understanding changes in extremes, to be better prepared 

The analysis demonstrates that the climate of the UK is expected to experience significant changes and these changes need to be understood so we can be prepared for them. 

The projected decreases in both extreme and average rainfall during February at the Principality stadium that we have seen from this work are clear demonstrations of some of the variability we should expect under climate change. While it is true that for the UK as a whole, UKCP18 data projects warmer, wetter winters and hotter drier summers, there is much variation across the country and indeed we have seen that rainfall in some places during February (a winter month) may decrease. In all the events analysed here, we have seen a projected increase in average daily minimum and maximum temperatures.  

It is clear from this work that the increase in global temperature is changing the climate of the UK in a variety of ways and these changes will be reflected in the climatic conditions of popular sporting events across the country. Some of these changes may benefit certain events, while others certainly won’t, but either way it is likely that our collective experiences of a number of popular sporting events will be altered in the coming decades due to increased global temperature. 

UK Climate projections can be found on the Met Office Climate Data Portal, with improved access to climate data and other resources, organisations can better understand and respond to climate change. Find out more in our news release.