Five climate categories and what they mean
Koppen's five zones are: Tropical (A) has year-round warmth and high rainfall. Arid (B) is dry with low precipitation. Temperate (C) has mild winters and warm summers. Continental (D) has cold winters and short summers. Polar (E) is perpetually cold. Each zone can be subdivided further by seasonal patterns, but these five capture 80% of Earth's climate variation and directly predict what plants can grow, what heating or cooling is needed, and what agriculture is viable.
Modern shifts and adaptation
Climate zones are slowly moving poleward and upward in elevation due to warming. Temperate zones are expanding while some polar regions warm faster than the average. Agricultural zones are shifting, forcing farmers to switch crops or migrate. Tropical regions may become too hot for current crops. Understanding the stability of historical climate zones helps assess where future food production, fresh water, and habitable regions will exist.