Palaeoklima

Palaeoklima refers to the ancient climate of the Earth or of a specific region, reconstructed from geological and biological records. The term is sometimes used interchangeably with paleoclimate, though palaeoklima as a label appears in certain linguistic or scholarly traditions and may emphasize long-term climate conditions of the past.

Reconstruction of palaeoklima relies on a range of proxies that preserve environmental information. Common sources include oxygen and carbon isotopes in marine carbonates and fossils, which provide signals of temperature and global ice volume; organic biomarkers such as alkenones; and various palaeobotanical indicators like pollen, spores, leaf stomatal patterns, and wood anatomy. Sediment characteristics, fossil assemblages, and speleothems in caves contribute additional climate clues, while ice-core records (where available) offer high-resolution data for more recent intervals. Together, these proxies help infer past temperature, precipitation, seasonality, atmospheric composition, and hydrological cycles over timescales from thousands to millions of years.

Applications of palaeoklima include constructing long-term climate histories, understanding natural climate variability, and placing modern climate change in a broader context of natural fluctuations. They also inform studies of the relationships between climate, evolution, biogeography, and mass extinctions. Limitations arise from dating uncertainties, preservation and diagenetic alteration of materials, proxy interpretation challenges, and uneven geographic sampling. Modern approaches combine palaeoklima reconstructions with climate models and astronomical tuning to test hypotheses about drivers of past climate change. Related topics include paleoclimatology, proxy records, and isotope geochemistry.