The Greeks began the formal study of climate; in fact the word climate is derived from the Greek word klima, meaning "slope," referring to the slope or inclination of the Earth's axis. Arguably the most influential classic text on climate was On Airs, Water and Places[3] written by Hippocrates around 400 BCE. This work commented on the effect of climate on human health and cultural differences between Asia and Europe.[3] This idea that climate controls which countries excel depending on their climate, or climatic determinism, remained influential throughout history.[3] Chinese scientist Shen Kuo (1031–1095) inferred that climates naturally shifted over an enormous span of time, after observing petrified bamboos found underground near Yanzhou (modern day Yan'an, Shaanxi province), a dry-climate area unsuitable for the growth of bamboo.Climatology is the study of the atmosphere and weather patterns over time. This field of science focuses on recording and analyzing weather patterns throughout the world and understanding the atmospheric conditions that cause themFurther identified subfields are physical climatology, dynamic climatology, tornado climatology, regional climatology, bioclimatology, applied climatology, and synoptic climatology