From a climatic point of view, World War I ended with a severe “bang” in late 1918. After four war years, a dramatic shift occurred in the northern part of the Norwegian Sea, at Spitsbergen, and lasted for two decades, until World War II started. Throughout the 20th century there had never been any climatic event as dramatic as this very pronounced one. At Spitsbergen, winter temperatures jumped up by 8ºC in a few years. The Northern Hemisphere became suddenly much warmer. The terms “Greening of Greenland” and “Warming of Europe” became common expressions.
There is nothing clearer than the commencement of a “big warming” that occurred at exactly the same time with the end of WWI, in November 1918. This is not difficult to prove. What is more difficult to show is that naval war caused this event. On the other hand, it is easy to point out the fact that nothing else had happened at that time that could have caused such a dramatic climatic shift. There was no earthquake, no major volcanic eruption, no particularly intense sun spots, no unusual El Niño, and no meteorite fell from the sky. There had been only a devastating naval war, waged for four years at about 2000 kilometres further in the south, around the Isles of Great Britain. As the warming lasted for two decades, until the end of 1939, the warming was sustained and could have remained in place for so long only because of the interiors of the huge and deep Norwegian Sea, which permanently receives plenty of water masses that have passed the British Isles, either on its Atlantic side or coming from the North Sea.
While the chapter focuses on linking the naval war of WWI to the “big warming” since 1918, the following two sections will demonstrate that general weather conditions during WWI already showed similarities to WWII conditions as long as naval war did not went global since 1942.
During WWI, naval war never went global but was fought around Britain, actually starting seriously only in the autumn of 1916 when new naval weaponry became fully available and devastatingly effective, particularly sub-marines (U-boats), depth charges, and sea mines. During the war year 1917, the German U-boats alone sank 6,200,000 tons. The total loss during the war was of 12 million tons, with 5200 ships, plus about 650 naval vessels. Most merchant vessels had been fully loaded with cargoes of all kind, from grain, ore, coal, crude oil, to whatever war parties needed. All that stuff polluted the sea and was taken along with the Gulf Current or the Norwegian Current up to the North, passing Shetland Islands and going either to the Barents Sea or, most of them, to the Arctic Sea, after passing Spitsbergen at the latitude of 79º North.
Sinking ships was not all that happened at sea. The sea was churned and turned “up side down” in many ways. For establishing a link between naval war in Europe and the sudden ‘big warming’ at Spitsbergen more explanations are needed. Before giving more details in this respect, the reader should become aware that both European wars around the United Kingdom, during the last century, had similar weather impacts. After a weather comparison between WWI and WWII, the section will outline the naval forces unlashed during the last two war years, from the autumn of 1916 to 1918, before concentrating on the ‘big warming’ at Spitsbergen and its WWI causes. It is frankly admitted that this investigation cannot fully prove the latter claim, however there is no better explanation available, yet. Actually, little efforts have been made to investigate the causation of the event anyhow.