Rising Waters and Temperatures: How Climate Change is Heightening Extreme Weather

What is extreme weather?

Extreme weather events occur when the weather is unexpected, unusual, unseasonal or is particularly severe. These are measured in comparison to the past recorded weather in that location.

As the climate is defined as the average weather over a 30 year period, one-off extreme events can have little impact on this. However, an increase in extremes can indicate that the climate is changing.

Why does extreme weather occur?

The weather system is very complex with lots of different factors impacting it - we can’t blame the weather presenter too much when it doesn’t end up as predicted!

Naturally occurring extremes can be attributed to changes in air pressure and temperature. In the UK, we hear a lot about the Jet Stream which is a result of warm air and the earth’s rotation creating high-speed winds. This is one example of a natural cause of large weather events by the system meandering in the atmosphere. 

How is climate change impacting our weather?

Warmer, sunnier days in the UK may sound like a great idea (especially on a wet bank holiday weekend) however these are not the only impacts seen from global temperature increases.

Higher temperatures also mean warmer oceans, this leads to increased evaporation and the increased moisture levels in the air result in much higher rainfall. Thunderstorms love hot, humid air, so will become much more frequent in these circumstances, leading to a higher chance of flash flooding.

For everyday weather conditions, luck will always play the main role in whether you need your raincoat or suncream. However, the combination of increased temperatures and moisture in the air shifts weather conditions in favour of extreme events.

What can be done to prevent these changes?

There are ways to alleviate the impact of these events; trees are our best friends here. Their presence reduces temperatures through shade and the release of water vapour through their leaves - it has been found that trees being present can reduce temperatures by 25℃ in some instances! (link) This is particularly apparent in cities and a great way to reduce the urban heat island effect, which is when urban areas accumulate more heat due to man-made materials absorbing more heat.

Trees canopies and roots also play a major role in preventing floods. They intercept the rain, slowing it down before it hits the ground, and they help the water penetrate faster into the soil.

The rise in greenhouse gases, carbon dioxide and methane, can be attributed to the temperature increases so stopping these at the source will have a massive impact on reducing the number of extreme weather events that occur, rather than reducing their impacts.

Large scale changes need to be made to reduce global emissions, however, there are things we can do individually to make a small difference such as using more public transport, switching to renewable energy and, of course, eating more plants!

So, when will London flood again?

It’s practically impossible to predict when the next heatwave is coming or when there will be more flash flooding due to the constant fluctuation of our weather systems.

What we do know is that the shift in climate will encourage more extreme weather events to occur. Working together to make changes now can help reduce the number we see in the future!