What Caused the UK Heatwave?

We couldn’t talk about the UK heatwave we have experienced without talking about the main causes, and talking about climate change. The global temperature has spiked this summer, with countries all across the world experiencing abnormally high thermometer readings as the planet starts to warm up in earnest.

But where does this all begin – how do emissions lead to temperatures spiking like this, and how did we end up at this point? Tracking the individual steps from pollution to climate change is very important so we’ve tried to put it into some simple to understand steps.


The root cause of global warming is the greenhouse gases being spewed into the environment. Not only is industry at fault, but many other factors have begun to be added into the mix. As greenhouse gases accumulate, they absorb infrared radiation from the sun, which warms up the Earth by locking in heat.

The problem is, as the Earth heats, this actually generates even more greenhouse gases in a ‘domino-effect’. Wildfires and melting of permafrost release carbon dioxide and methane respectively, and rising water temperatures also release gases into the atmosphere which they have held onto for a very long time.


Our planet has a fairly complex system of air and ocean currents which circulate around the globe, all of which are disrupted by rising air and sea temperatures. The gulf stream in the sea and the jet stream in the air are currents which affect the temperature and weather here in the UK and the rest of the Euro-zone.

As the air temperature becomes warmer and ice melts in the Arctic, the high altitude jet stream becomes slower and warmer, contributing to even more warming effects in the northern hemisphere around the North Atlantic. Normally, cold ice would create a barrier of cold air preventing it from moving north, but less ice means this barrier is not so strong anymore.

Additionally as ice melts the Arctic ocean absorbs a lot more heat from the sun, that would previously have been reflected off the surface back away from the ocean. Ice caps are somewhat of a reflective barrier themselves, and as they retreat this knock-on effect makes the seas even warmer.


The culmination of these factors, the main cause of the UK heatwave, is the slowing down of the jet stream air flow, with the current lazily looping above the country as opposed to achieving its usual speed and trajectory. This puts our temperatures in a bit of a calm ‘limbo’, and stops rain from falling. In addition, there is also a large high pressure weather system over Europe, which is sending winds northward as opposed to letting them flow eastwards.

The UK’s heatwave therefore, is the direct result of climate change – these conditions are not ‘business as usual’ for the weather systems we are used to living beneath. Meanwhile, economically speaking, industry still hasn’t changed production practices to meaningfully combat the changes in our climate and weather, or offset emissions by reforesting or otherwise removing carbon from the atmosphere.

It’s really no longer a matter of theory – climate change is now a reality of our time, and things are likely to get more extreme in the years to come.