Saturday 13th January 2018
After the end of a year that has been declared to be the one of the warmest on record (see http://www.bbc.co.uk/news/science-environment-41859288 and http://www.noaa.gov/news/2017-was-3rd-warmest-year-on-record-for-us), a year marked by yet another series of extremes events (e.g. floods, droughts, hurricanes, wildfires), you might think that 2018 would be relatively quiet in comparison. Not a bit of it … at least not based on the first two weeks of the new year. January 2018 has started in ferocious mood, with a ‘bomb cyclone’ (technically ‘explosive cyclogenesis’) in North America, extreme heat in Sydney, coastal storms in Britain, and heavy rain, flash floods and mudslides in California. It’s unclear whether this mood will last through 2018 (e.g. see an article in The Conversation) but the signs are not positive.
Much of the mainstream media coverage of these extreme events understandably focuses on the ‘disaster’ element: infrastructural damage, travel disruption, and the human tragedies, lucky escapes or heroics. But is there room for just a little more science? Having skimmed the media coverage of the later two events – British coastal storms and Californian mudslides – two things strike me.
The first is an observation that despite abundant opportunity to use terms such as ‘geomorphology’, ‘geoscience’. ‘earth surface processes’, ‘topographic change’ or ‘landscape change’, rarely is this done, even alongside the potentially suitable graphics that accompany such articles. Surely, readers of the BBC and other quality news outlets can handle a smattering of these terms as part of a wider, human-focused story?
The second, and more important, is the underlying tone of surprise that seems to accompany the reporting of the sediment movement that may be associated with extreme hydrometeorological events. Large amounts of sand are moved during extreme coastal storms, leading to chopping back of the beach face, creation of ‘sand cliffs’, and shifting of the course of beach-traversing rivers. Sediment-laden flows are generated by heavy rains on steep, weathered, burnt, hillsides. Isn’t all this to be expected? You can forgive British readers for not being so familiar with flash floods and mudslides that sometimes follow intense fires. But anyone who has visited the British coastline on a regular basis should know that in the absence of hard engineering works, sandy beaches are highly dynamic. Extreme wave events typically accomplish substantial erosion, with large volumes of sand commonly moving offshore, but ensuing large, moderate and small wave events will gradually move this sand back onshore to ensure beach rebuilding. Case studies from Ireland have shown how sandy beaches can suddenly disappear and then re-appear months, years, or even decades later (http://theconversation.com/why-beaches-lose-their-sand-and-then-suddenly-reappear-77503). Much depends on the sequence of different size wave events, and there are legitimate concerns over the apparent greater frequency of the extreme events that may be disrupting the historically roughly balanced rhythm of offshore-onshore sand movement and initiating a longer term trend towards increasing erosion. But even if this is the case, there are opportunities as well as threats. Previous events in places like eastern Ireland, west Wales and the English coastline have shown how mobile beach sand can lead to serendipitous discoveries, including new exposures of mid Holocene submerged forests, Bronze Age deer antlers and wattle walkways, as well as numerous other archaeological finds. For flanking coastal wind-blown sand dunes, erosion and continual sand mobility – perhaps during extreme wave or wind events – in many cases may actually be essential for maintenance of biodiversity, as shown by case studies of dunes along the south and west Wales coastlines (https://stephentooth.wordpress.com/2015/10/29/10-reasons-why-10-rheswm-pam-8/).
In other words, extreme events provide both threats but also opportunities for renewal, discovery and change, with potential for geotourism, ecotourism and archaeologically-based tourism initiatives. Admittedly, in the aftermath of events like the Californian mudslides that have led to serious infrastructural damage and loss of life, it’s hard to see any positives. But in other cases, can the opportunities provide a counternarrative to the prevailing tone of pessimism or surprise commonly associated with reporting on extremes? This idea of ‘erosion as attraction’ has been raised by others (e.g. Matless, D. 2016. Climate change stories and the Anthroposcenic. Nature Climate Change, 6: 118-119, doi: 10.1038/nclimate2862) but why does this alternative perspective rarely feature in the mainstream media coverage of extreme events?