On the northern fringes of the Black Sea temperatures on land and sea in winter are similar to the southern Baltic. The main difference between these two areas is that precipitation is greater around the Baltic making it greener. This would have been attractive to Bronze Age dairy farmers living by the Black Sea where there were only pockets of lush pastures around its shores suitable for dairy farming. Around the southern Baltic however there was a vast area to expand into.
The spread of Indo-Europeans and the spread of cattle farming, especially dairy, are closely associated. It is therefore no surprise to find at the very beginning of the Norse creation myth Audhumla, a hornless cow with four udders, milk nourished Ymir the first being and later by licking the ice she helped to free Buri who was also nourished on her rich milk and begat a son called Burr.
The Caspian Sea is in the middle of a continent and stretches ten degrees in longitude north to south, which is the equivalent from the Alps to Tunisia but it has varied greatly in size over time. At its northern end it is surrounded by windswept steppes open to Siberian blasts. It is also shallow here and liable to freeze.
This is in contrast to its southern end, which is surrounded by high mountains that catch the rain and remain green most of the year. Yet only a short distance up the coast on its eastern side the land quickly becomes arid and inland is the Kara Kum Desert – searingly hot in summer and numbingly cold in winter.
During the melting of the Scandinavian Ice Sheet the Caspian Sea virtually doubled in size for a time. This increase was most dramatic in the north flooding a large area of the steppes. Now it is slowly shrinking as it is reliant on just a few major rivers, mainly the Volga, to sustain it but these waters are also being abstracted for irrigation, industry and domestic use. It is likely that during the early Bronze Age the Caspian was bigger than it is now.
Yggdrasil and Middle World 