February 27, 2019

expert reaction to wildfires in the UK

Reactions to wildfires in the UK.

Prof Robin Pakeman, Plant Ecologist, The James Hutton Institute, said:

“Normally in late winter and early spring fire risks are low because of the cold and wet. However, the heather’s leaves are old or dead at this time of year and many of the grasses that grow with it, such as purple moor-grass, are reduced to dead leaves. If there is a long period without rain, then these dead leaves dry out an become much more flammable. So if a fire is started then the vegetation can burn very quickly and fires can spread rapidly. As spring progresses and the heather and grasses produce new leaves then fire risks will decline again until later in the summer.”

Dr Jon Shonk, NCAS scientist in the Meteorology Department at the University of Reading, said:

“There have been a couple of reports of out-of-control wildfires in Yorkshire and Scotland during this warm spell, which has seen record-breaking temperatures in parts of the UK. Dry conditions are favourable to the spread of wildfires, with periods of low rainfall coupled with low humidity increasing the ability of the fire to spread. Much of this winter in the UK has been dry, with both January and February rainfall totals well below average. The warm sunny days we have been experiencing also tend to lead to very low values of relative humidity. In combination, these factors are likely to have allowed fires to spread, fanned along by the wind.”

Dr Rory Hadden, Rushbrook Senior Lecturer in Fire Investigation, University of Edinburgh, said:

“The UK is experiencing a period of abnormal weather which has complex interactions with the natural environment. Although the high temperatures play a role, changes in the longer-term weather are possibly more significant. The very dry winter we’ve experienced means that vegetation has become drier which, coupled with increased human activity outdoors means that the likelihood of ignitions is increased. Fires in winter are not uncommon – but the frequency may increase as we experience longer periods of extreme weather.”

Dr Bjorn Robroek, Lecturer in Ecology, University of Southampton, said:

“We have seen a relatively dry winter this year, which means that more peat on the moorlands is susceptible for combustion than other years. In addition to that, previous fires in the area can add to this effect as burned peat doesn’t hold water well, making it drier.

“The preliminary results of a NERC funded project, show a relatively fast regrowth of vegetation that can act to spread a fire (it is unclear how the combustion took place). Together with remaining dead roots from the previous fire, a new fire can spread relatively fast.

“Can this be the result of climate change? To a certain extent, yes. While it’s hard to attribute single events to climate change, we are expecting precipitation patterns to change, with longer dry periods even in winter. This has important repercussions on ecosystems that depend on rainwater as their main source of water.”

Dr Thomas Smith, Assistant Professor in Environmental Geography, London School of Economics (LSE), said:

“Moorland fires are quite normal in February. This is the ‘muirburn’ season, when Natural England permit fires on moorlands, before a ban on burning around mid-April. Looking at the satellite image for Tuesday (26 February), there were plenty of well managed fires burning across Northumberland and Highland moor sites.

“The situation at some sites (including in Saddleworth and Somerset) is that some fires have got out of control. The weather has been dry for over a week, and the unseasonably warm temperatures have driven relative humidity down to ~30%. The perfect conditions for a fire to spread with wind. These fires are likely to be low severity though (not causing much damage to the soil) due to the soil being very wet still after the winter. In this respect, many of these fires are probably helping to reduce fuel load (burnable vegetation) for future potentially more severe fires in the late spring/summer.

“The fires are occurring due to favourable weather conditions. It is not possible to attribute this short spell of warm, dry weather to climate change. However, these warm spells will become more likely with climate change, and so we should expect fire activity like we’ve seen this week to happen more frequently in future.

“The Fire and Rescue Services will probably look to protect property and infrastructure, and may well put out fires that are leading to smoke pollution affecting nearby settlements. However, many fires not affecting nearby property/populations may not need to be fought directly, as these fires will help reduce the risk of future, more severe fires.”

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