Drought in Portugal. Photo: Bert Kaufman

Scientists Predict More Extreme Weather for Northern Hemisphere

3 minutes read

 UK summers will become hotter as climate change continues

A research paper has just been published by scientists working for the famous Potsdam Institute for Climate Impact Research and the Geophysics Dept of the University of Madrid. They analysed temperatures for the Northern hemisphere and used an advanced computer climate model, which predicts more extreme weather events. These events are called “3-sigma” events, which means they are very abnormal in statistical terms, but as the climate changes, they will get more frequent. In practical terms, these will be exceptionally hot summers, as we have seen in the UK in the last few years.

The computer model predicts more and more of these outcomes, including record-breaking hot weather, all over Europe in the next 30 years. They used various emissions scenarios to generate the results, but it became clear that over land, there were going to be significant periods of hot weather, although the low-emissions scenario was the least unfavourable outcome.

The report says, “The limited global warming to date thus already strongly increased the frequency of heat extremes on monthly to seasonal time scales, exacerbating societal impacts. This raises the question how and how rapidly this trend is likely to continue under future warming, which is expected to be substantially larger than the 0.5º C observed so far.”

Abberton Reservoir, UK, in drought conditions, with submerged bridge visible.  Photo by Glyn Baker
Abberton Reservoir, UK, in drought conditions, with long-submerged bridge visible. Photo by Glyn Baker

They note that previous “3-sigma” extreme weather events have caused “serious impacts to society, causing many heat-related deaths, massive forest fires or harvest losses.” The Mediterranean area is particularly vulnerable to these events and is also on a long-term drying trend. As time goes on, even more extreme “5-sigma” events will occur, “The projections show that in the near-term such heat extremes become much more common, irrespective of the emission scenario. By 2020, the global land area experiencing temperatures of 3-sigma or more will have doubled (covering around 10%) and by 2040 quadrupled (covering around 20%). Over the same period, more-extreme events will emerge: 5-sigma events, which are now essentially absent, will cover a small but significant fraction (around 3%) of the global land surface by 2040. These near-term projections are practically independent of emission scenario.”

The report warns that countries need to take significant steps to ensure climate resilience and mitigate the ongoing problems if the worst scenarios are to be avoided in the future post 2040. The disruption caused by extreme weather events will be severe, if this research is correct. Damaging the climate through greenhouse gas emissions is a really serious mistake which future generations will curse us for.

Historic and future increase in the global land area affected by monthly heat extremes research paper

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