The First International Symposium of Climate Change and Dendrochronology in Caspian Ecosystems

Since the middle of the 19^th century the amount of atmospheric carbon dioxide has increased by about 25 percent. Most regions in both the northern and southern have warmed up. The average global temperature has increased from 0.5 ^oC to 0.7 ^oC since 1860. However the mean global temperature declined between 1940 and 1965 in spite of the continuous increase in heat-trapping gases in the atmosphere. But some general circulation models (GCMs) were reported that the mean annual global temperature will rise by 1.5 to 5 ^oC in summer over a period of 100 years and warming trends will vary from region to region around the world. A number of recent simulation studies on climate response to the doubling of CO₂ have confirmed the earlier estimates of an increase in global surface temperature over the next century by 3^oC with confidence interval of 1.5^oC with a warming enhancement at high latitudes of possible greenhouse-gas-forced temperature changes predicted that between 1990 and 2030 the global mean temperature will increase by 0.4-2.3^oC with a best estimate in the range of 1.0-1.7^oC. Since by different methods the predictions are varied but totally it showed that the climate was changed and continuousness.

Dendrochronogy studies mainly deals with the dating and analysis of tree-ring layers in wood in order to find relationships between past forest disturbances and tree productivity and growth. Dendro and chro are Greek words meaning tree and time. Chronology is the science of measuring time on a regular basis. Analysts are beginning to deal with special variations in both tree-ring chronology and climatic variables.

We can use tree-ring in many different scientific areas. Fore example, dendroclimatology, which is a subfield science of dendrochronology, utilizes dated tree rings to study past and present climate. Dendroecology is also a subfield of dendrochronology which utilizes dated tree rings to study ecological and environmental problems. Dendroecology can provide quantitative and precise information on past environmental conditions associated with past tree growth activity. Tree-ring studies have played an important role in dendrochronology by providing a long term historical perspective of events.

Tree-ring analysis has been extensively used to reconstruct past climatic fluctuations. The best dendrochronological material for this kind of study often comes from extreme environments, such as semiarid sites and mountain regions where tree growth is clearly limited by climatic factors.

So many meetings have been done in the last decades and discussed about climate changes. For example in June, 2007, Environment Ministers from 28 countries met at Sweden for an informal discussion on international cooperative action on climate change. As a result, by changing environment in the world, this conference intends to know what happened in  Caspian environment during in the last decades.