Palaeoclimatic data provide crucial insights into Earth’s past climate system and help scientists understand long-term patterns, natural variability, and the mechanisms that drive climate change. Since instrumental climate records extend back only about 150 years, palaeoclimate research relies on natural archives and indirect indicators, called proxies, to reconstruct environmental conditions that existed thousands to millions of years ago. These sources preserve evidence of temperature, precipitation, atmospheric composition, vegetation, and oceanic conditions. Each proxy responds to climate in distinct ways, and by combining multiple records, researchers develop a clearer picture of past climate dynamics. Ice cores are among the most valuable palaeoclimate archives, particularly for studying high-latitude climate change. Drilled from the ice sheets of Antarctica, Greenland, and high mountain glaciers, ice cores preserve annual layers of snowfall compacted over hundreds of thousands of years. These layers trap tiny air bubbles that contain samples of the ancient atmosphere, allowing scientists to directly measure concentrations of greenhouse gases such as carbon dioxide, methane, and nitrous oxide. The isotopic composition of the ice, especially ratios of oxygen and hydrogen isotopes, serves as an indicator of past temperature. Dust particles, sea salts, volcanic ash, and chemical impurities embedded in the ice provide additional information about wind patterns, aridity, volcanic eruptions, and oceanic conditions. The remarkable continuity and precision of ice-core records make them essential for correlating climate changes with external drivers such as orbital variations and internal factors such as feedbacks in the Earth system. Ocean sediments constitute another major repository of palaeoclimatic information. Over millions of years, particles settle to the seafloor,