MOSCOW, November 22. /TASS/. Researchers from the Siberian Federal University (SFU) as a part of an international team expect that under maximum-level emissions of greenhouse gases, the warm season might become longer by the end of 21st Century. This conclusion was drawn based on the analysis of annual tree ring growth along the Tibetan Plateau. The article outlining the results has been published in the International Journal of Biometeorology.
In the territory of the Tibetan Plateau, the world’s highest plateau, global warming factors exceed worldwide figures. Therefore, it is crucial to forecast processes with the local vegetation.
''When compared to the 1960-2014 timeframe, the vegetation period in Tibet by the end of 21st Century will expand by 82 days in correlation with the RCP 8.5 (the scenario when the amount of greenhouse gases in the atmosphere is steadily going to grow)," the authors of the study warned.
The vegetation period is the time of the year when plants can grow. Usually, the moment when the daily average temperature rises above 5 degrees Centigrade is seen as this period’s beginning. The longer the warm season is, the wider the tree trunk grows, and so the larger annual rings are.
Consequently, by studying the width of annual tree rings, the duration of the warm season can be determined.
The researchers analyzed the tree rings’ annual growth and found a connection between climate factors and the rings’ growth. Based on the analysis results of the interaction between air temperature and the rings’ width, the researchers hammered out three possible scenarios on climate change in the coming century depending on the amount of greenhouse gas emissions the Earth churns out. In all three scenarios, the prolongation of the period of annual rings growth is present. According to estimations, by the end this century, the vegetation period will increase by three weeks under a minimal volume of pollutant gases, by 50 days with an average volume, and up to 82 days in a maximum volume case.
The data estimated by scientists hold true only for Tibet. However, they provide an estimate of the Earth’s possible climate change for the future.