I’ll be astonished if anyone missed the fact that last Sunday, 11 November, 2018, marked the centenary of the ending of the First World War. I talk a lot about how the Earth is a system, with every change or interaction having a knock-on effect somewhere else, and I also talk, though perhaps a little less, about how humans have an impact our planet.
Over the past few weeks or so I’ve seen a number of relevant articles about the impacts of war on the world in which we live — not just on its human population but on the topography, the climate and the atmosphere. This week I’ve gathered a few of them together.
I’ll ask you to excuse the fact that they aren’t all brand-new in terms of news, and also that for one of them I haven’t been able to access the original research document and so am reduced to using a report from elsewhere — something I wouldn’t normally do.
Geology and the First World War
Geology influences human activity and settlement and has done since the dawn of time. It makes sense that it will have had an influence in how we fight wars. This week Forbes magazine included a very interesting article, though short, on geology and the First World War.
Anyone who has been to the battlefields of northern France and Flanders can hardly fail to notice this impact that the almost-continuous bombardment has had on the surface topography, even after a century. The article outlines how the bombardment scooped out bomb craters and how the infilling of the craters left its distinctive shape.
This also gave us a new word: “bombturbation”, which describes the disturbance of the soil by the activity of warfare.
The plains of France and Flanders are largely sedimentary, but the article observes some variation in this. The soft clays and mudstones of the lower ground were the cause of the life-sapping mud that’s so familiar from images. The higher ground, which is made of harder rock such as limestones, has a different problem — it’s much harder to dig into a defensive position.
And, as the article notes, geology was also influential elsewhere. In the rocky front of the Dolomites, where the Austrian and Italian armies were in opposition, trench warfare was replaced by armies digging in and the key weapon was one of undermining and destroying the enemies position, trading on the collapse of the mountainside.
In one sense, this is blindingly obvious and, as I say, I’m conscious that this piece is to an extent a rehash of another. But it was an interesting article and something we perhaps don’t think enough about.
The Bombing Raids in Europe and the Ionosphere
I am not a meteorologist and reading up on atmospheric physics isn’t the way I’d normally choose to spend my time, but occasionally there are exceptions. Back in September, a piece of research was published on the analysis of data collected during the Second World War about the level of ionisation (the amount of charged electrons) in the upper atmosphere.
Normally, as the research points out, we associate ionisation with solar influences from above, but the analysis of these records suggested that the huge bombing raids in western Europe during World War 2 influenced it from below, with decreased levels of ionisation during the intense bombing raids.
The data were recorded above London but the change was greater during raids over continental Europe than it was during the Blitz, despite the greater distance of the firmer. This is may be associated with the relative sizes of the bombs involved.
There is, according to the European Geosciences Union, much more to be done, but they hope that the research will help: “ to further understanding of how natural forces from below, like lightning, volcanic eruptions and earthquakes, affect Earth’s upper atmosphere”.
Global Cooling and World War Two
Episodic global cooling (i.e. caused by a particular event rather than as part of a natural cycle) is anything but unknown. The atmospheric cooling from the eruption of Tambora, in Indonesia, in 1815 led to the following year being known as ‘the year without a summer’, while the Laki fissure eruption Iceland in 1783-4 caused famine and crop failures and is credited with having played a part in precipitating the French Revolution.
The cooling occurs because tiny particles known as aerosols are thrown into the atmosphere and, by absorbing or reflecting sunlight, have a cooling effect. Other natural events such as meteorite impacts, and natural or man-made events such as forest fires, also produce aerosols and can have a cooling effect.
Large-scale destruction as a result of war, with associated burning, might also have such an effect — the theory of the nuclear winter which might result from a major nuclear conflict. To my knowledge the actual extent of this has never previously been assessed, but a research piece in the Journal of Geophysical Research this summer did consider the impact of the bombing of Japan in 1945.
Interestingly, although the study did find a small cooling effect, there were too many uncertainties to allow a conclusion one way or the other. A larger event might, however, create significant cooling — just as natural hazards themselves have done.