17/07/2018

Munich Re’s Ernst Rauch discusses weather bombs ahead of FERMA Seminar plenary session

weather bomb

“Climate researchers expect that strong and very strong storms – similarly to hurricanes – will increase in frequency, with so-called ‘weather bombs’ also being possible. Weather bomb is the term used to describe an event in which an area of low pressure intensifies considerably in a very short time.”

In an article originally published in the German newspaper “Münchner Merkur” on May 30th, 2018, Ernst Rauch – Munich Re’s Chief Climate and GEO Scientist – answered questions on how expensive these weather bombs are for insurers, how things are looking in Europe and his predictions for this year, and the consequences of climate change.

Alongside Rauch’s explanation above, the Met Office defines 'weather bomb' as an unofficial term for a low-pressure system whose central pressure falls 24 millibars in 24 hours in a process known as explosive cyclogenesis. Rauch goes on to describe these as wind speeds significantly in excess of 160 kilometres per hour over very large areas.

How expensive are such weather bombs for insurers? Such events may well lead to insured losses running into the low double-digit billions. We’ve not yet seen this from a single event in Europe, but we have seen it as the total of a series of winter storms in one season.

Raunch on climate change

“By the end of the century, we’ll end up with warming of four, five or even six degrees. Which is very worrying.”

Rauch’s work at Munich Re includes forming calculations taking historic weather events that have already happened alongside simulating meteorologically possible scenarios in order to work out how costly that scenario may be. The most interesting part here is that three parameters can alter due to climate change – and the question Rauch is concerned with is how strongly they do so.

With average global temperatures rising, the three vulnerable parameters Munich Re must be aware of in forming their simulations are the frequency of hurricanes, their intensity, and the fact that hurricanes may occur in regions where they have never occurred before.

Despite some disregard to the creation of simulations on historical data, there’s currently no reliable study saying that the overall frequency of hurricanes will increase. However, what scientific studies do indicate is that the number of strong storms in the coming decades may increase at the expense of less frequent, weaker events – and it’s the big hurricanes that are the relevant loss events for insurers and reinsurers.

When looking at Europe in particular, Rauch stated: “the big loss scenarios for insurers are in fact winter storms, like Kyrill in 2007... Two to three hundred million people can be affected by a single event – significantly more than with a hurricane… Because a winter storm in Europe affects so many buildings, insurance losses can quickly mount up to several billion euros.”

When asked if winter storms are the biggest risk in Europe, Raunch clarified that they do have the potential for the biggest insured losses, with less demand for coverage against other natural hazards like flood or earthquake. At the same time, we’re seeing an increase in heavy precipitation following severe summer thunderstorms and severe hail damage. The data base is less clear for tornadoes, but physics indicates that, in a more humid climate, these will increase in frequency and intensity in the future – albeit starting from a small base.

Mr Rauch will be at our plenary session on Day 1 of FERMA Seminar Monday 8th October 2018 in Antwerp, discussing the topic of climate change in Europe further. Spaces are filling up fast so visit https://www.ferma.eu/ferma-seminar-2018 to find out more about the intense programme and sign up today. Ernst’s bio is in the Speakers section.

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