It's hard to pin down when the Little Ice Age started. However the cause was the advance of pack ice in the Atlantic, similiar to what causes real ice ages. There is some evidence that glaciers worldwide also advanced.
Here are a series of events that led into the Little Ice Age: 1250: the Atlantic pack ice began to grow 1300: Warm summers stopped being dependable in Northern Europe 1315: The rains and Great Famine of 1315-1317 1550: Theorized beginning of worldwide glacial expansion 1650: The first climatic minimum It probably ended in about the mid 19th century, although some say it continued until 1930. What ended it is theorized by some to be the advance of industrialization (and some say it was the start of an ice age that we inadvertantly delayed). As for more specific causes, it probably wasn't any one thing but a mix of factors that caused it.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.