The book seeks to demonstrate that the industrialized world contributed to at least two significant climatic changes during the 20th century, viz. WWI and WWII. This became particularly obvious when an arctic winter befell Northern Europe only four months after World War II had started, ending a pronounced temperature rise all over the Northern Hemisphere which had started with the end of WWI in 1918.
The 'Big Warming' in 1918 started at the Norwegian Island Spitsbergen high in the North bordering the Arctic Sea. Not far away a devastation naval war had been deterred for four years. Winters since 1918 were the warmest for several hundred years. The expression 'Greening of Greenland' and 'Warming of Europe' established. Suddenly, exactly two decades after WWI the trend was reversed. Without any geophysical event, e.g. volcano, earthquake, or meteorite Northern Europe plunged to Ice Age conditions in winter 1939/40. For North Germany it was the coldest winter for 110 years. Not nature had caused weather to change the course but huge naval armadas going into action since September 1st 1939.
Two further arctic winters followed. Each is a clear demonstration of naval impact on North and Baltic Sea heat budget usually sustaining moderate regional winters. After German invasion of Norway followed a record winter for South Norway 1940/41. Winter 1941/42 became a record winter for Stockholm after Germans mobilised about hundred naval vessels; viz. 10 large mine layers, 28 torpedo boats, 2-3 dozen minesweepers and many hundred bomber and fighter airplanes to attack Russia over six long months in the Baltic Sea, while the Russian operated with six big war ships, 21 destroyers, 65 submarines, six mine layers, 48 torpedo cutters and 700 air planes. Arctic conditions all over Northern Europe were the prompt result.
With commencement of global naval war since Pearl Harbour had been attacked on 7th December 1941, huge sea areas in all oceans were churned and turned up side down for almost four years. The Allies completed over 300.000 Atlantic voyages and lost several thousand ships. 800 German U-boats sunk. Some hundred thousand aerial bombs, and depth charges, and sea mines exploded above or down to 200 meters below the sea surface. A global cooling for four decades was the immediate and lasting result until 1980. From this date on the WWII impact may have reversed, resuming and accelerating the pre-WWII warming trend.
With the end of the Little Ice Age in 19th century, the use of the oceans no longer remained 'neutral'. Day by day huge water masses are 'turned about'. What it means in climatic terms is demonstrated by explaining the climatic impact of the war at sea. Understanding the global warming trend since 1880 primarily means understanding the structure, conditions and changes of the oceans and seas.