Your answer is Hydroelectric
Answer:
The iceman and his site reveal that between 9,000 and 5,000 years before present the Alpine glaciers were smaller than in the second half of the Holocene (the last 10,000 years of geological history).
Explanation:
The orders were to take everything that they can, and burn and ruin everything that they can't take. The idea was to destroy infrastructure completely so as to weaken the southern population and the southern support for the war. They would burn farms and pillage everything leaving nothing standing.
Family sells its farm and moves to a large city is the answer