Palaeoclimatic data refers to information about past climates, which scientists use to understand the Earth’s climatic history and how climate has changed over time. Since direct measurements of climate variables such as temperature, precipitation, or atmospheric composition have only been systematically recorded for the last century or so, researchers rely on indirect evidence preserved in natural archives. These archives provide a window into past environmental conditions and allow reconstruction of climate patterns over timescales ranging from decades to millions of years. Palaeoclimatic data sources can be broadly categorized into terrestrial, marine, and atmospheric proxies, each contributing unique insights into different aspects of past climate. One of the primary sources of palaeoclimatic data is ice cores. Ice sheets and glaciers, particularly in Greenland and Antarctica, accumulate layers of snow annually, which over time compress into ice. These layers trap air bubbles containing ancient atmospheres, allowing scientists to measure past concentrations of greenhouse gases like carbon dioxide and methane. The isotopic composition of oxygen and hydrogen in the ice also provides information about past temperatures. Ice cores can yield continuous records going back hundreds of thousands of years, making them invaluable for studying glacial-interglacial cycles and abrupt climate changes. Tree rings, or dendrochronology, provide another important source of data. Trees in temperate regions produce annual growth rings, whose width and density are influenced by climatic conditions such as temperature and rainfall. By analyzing these rings, scientists can reconstruct climate variability at a yearly resolution, often spanning several centuries or millennia. Tree-ring data is particularly useful for studying past droughts, floods, and extreme climatic events. In addition, combining tree-ring data from multiple sites allows reconstruction of regional or even hemispheric climate patterns. Sediments, both from lakes and oceans, offer further insights into palaeoclimate. Lake sediments accumulate continuously and often contain pollen, diatoms, and other biological indicators that reflect past vegetation and climatic conditions. Pollen analysis, or palynology, can indicate the types of plants that dominated an area at a particular time, which indirectly informs scientists about temperature and precipitation. Similarly, ocean