Lightning Risk. In a world increasingly driven by quantitative Risk Assessment (QRA) techniques it's important to understand what the predicted impacts are as a result of our current trajectory (as humans), i.e. the direction of travel that the population of planet earth seems to be following - in terms of climate change:
Increasing Lightning Risk trend
From recent research. Some in the Lightning community are predicting strike frequency increasing by +12% to +24% : the phenomenon appears to be worsening with climate change (2016).
According to research out of the University of California, Berkeley (2014); Lightning Risk and its frequency is set to increase far more in a world under climate change – but researchers can still not predict with any helpful precision, where or when those strikes will occur.
Research published in the journal "Science", found warming conditions would result in 50% more lightning strikes by the end of the century.
So, the risk of lightning may increase by about 12% per 1ºC of warming, resulting in about 50% more strikes by 2100. Unless you're in the lightning business, this is not good news! Especially, as uncertainty remains regarding where these increases will impact and to what extent. This is not wholly unexpected - coming from a country which boasts "the MetOffice" (with all their immense computational power), yet, for the most part, their forecasts are known to carry high levels of uncertainty. Therefore, trying to predict patterns on a global scale would seem to exceed the art of the possible using today's resources.
“There could be regions that get a lot of lightning strikes today will get even more in the future”.
Lightning - world records
The World Meteorological Organisation (WMO) has recognised two world records for extreme lightning:
- the longest-distance flash covered 321 kilometres in 2007 in Oklahoma, and;
- the longest-duration flash lasted 7.74 seconds in southern France in 2012.
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What does more lightning mean?...
Without wanting to state the obvious - more lightning over the coming years means more risk! Is the relationship linear? Not really because the intensity of the lightning is also likely to increase alongside the frequency. Therefore, systems that were designed 'n' years ago to cope with the lightning current of yesteryear may need to "level-up" (upgrade) in order to handle its future magnitude. This is one reason why standards' committees around the world, responsible for standards such as BS EN 62305, NFPA 780 regularly review this data. To try and future-proof design practices to cope with imminent changes in frequency/risk.
There have been a number of changes in the Lightning Standards recently (2014). If you're unsure if these might affect your situation, why not drop us a line below in the LiveChat or email?
This post is written by Ian Griffiths, Principal Engineer at GreyMatters, an Earthing & Lightning Consultant of 27 years, one of the top 1% accredited CDEGS consultants and professional advisor to international utility companies, data-centre and infrastructure developers.
Tagged: Electrical Earthing System Design, lightning, lightning activity, lightning danger, lightning physics, Lightning Protection, lightning transient studies, risk management, what to do when lightning strikes