Evidence from Past Climates Introduction Although mankind may be changing the climate through the emission of greenhouse gases, climate also changes in response to natural factors, including variations in sunlight, changes in ocean circulation and volcanic eruptions. Dendroclimatology the Earth's history climate has fluctuated between periods of relative warmth and relative cold. Palaeoclimatology is the study of climate and climate change prior to the period of direct instrumental measurements. Instrumental records of temperature and other climatic variables span only a dendroclimatology fraction of the Earth's climatic history, and dendroc,imatology provide an inadequate perspective on climatic variation and the evolution of the climate today and in the future.

milankovitch cycles

Two related subdisciplines are dendroclimatology and dendroecology. The former uses the information in dated rings to study problems of present and past climates, while the latter deals with changes in the local environment rather than regional climate. Successful applications of dendroclimatology and dendroecology depend upon careful stratification.