Final answer:
Fossils and tree rings are proxies for studying past climate conditions, as they provide indirect evidence of climatic variables when direct measurements from the past are unavailable. These proxies contribute valuable information to our understanding of global climate change, its causes, and its impacts.
Step-by-step explanation:
Proxies of Past Climates
Each year, fossils are brought up showing the remains of past species. These fossils, including the remains of organisms like foraminifera, provide priceless insights into past climates as they reflect conditions such as seawater temperature. For example, the coiling direction of foraminifera shells gives a relative idea of whether temperatures were cooler or warmer at the time of their existence.
The record of tree rings reflects growing seasons by providing detailed data on annual climate conditions. Rings of trees are wider during years of ample water supply and narrower during drought years, thereby indicating past climatic conditions.
Geologists use these proxies—fossils, tree rings, ice cores, and sediment cores—to study the evidence of current and past global climate change, its drivers, and the documented results. A famous example is the fossil evidence from the Green River Formation in Wyoming, indicating a subtropical climate akin to Florida's today, suggesting warm temperatures during the Eocene epoch. It is through such multi-faceted evidences that historic climate patterns are inferred.