Based on the study of tree rings, a group of international scientists from the Johannes Gutenberg University in Mainz published a model of the climate of northern Europe for the last 2 thousand years.
Someday the whole north of Europe will be covered with glaciers like in Norway
To reproduce the climate from 138 BC to the present day, Professor Jan Esper's team used ring density data for subfossil pine trees from Finnish Lapland.
The data obtained showed a clear trend towards climate cooling. “We found that existing attempts to reflect the climate of the Roman and Middle Ages skewed the data towards lower temperatures. Such research provides a good contrast in the context of warmer periods in history,”says Esper.
Was the climate during the Roman era and the Middle Ages actually warmer than today? And why are early periods of warming so important in assessing the current state of the climate? Paleoclimatology attempts to answer these questions. Scientists are analyzing indirect indicators of climate variability such as turbid cores in a block of ice, ocean deposits, in order to reconstruct the climate of the past. The annual increase in the rings is important evidence of the warming and cooling of the climate over the past 1000 and 2000 years.
Scientists from Germany, Finland, Scotland and Switzerland have studied the density of tree rings in Finnish Lapland. In this region, it is not uncommon for trees to fall into one of the many lakes, where they can retain their properties for thousands of years. The density of annual rings of subfossil pines, correlated with the summer temperatures of this region, the transitional zone of the Nordic taiga. The high-resolution model reproduced temperatures from the Roman and Middle Ages periods. Not only periods of warming were identified, but also of small ice ages.
In addition, for the first time, based on data obtained from year circles, researchers were able to trace a longer trend towards cooling over the past 2 thousand years: each new millennium is accompanied by a cooling of 0.3 degrees Celsius. This process is explained by a gradual change in the position of the Sun and an increase in the distance between the Earth and the Sun.
“The obtained results may seem insignificant, but in the conditions of global warming, which today has indicators of less than 1 degree Celsius, they cannot be neglected. New data show the need to reassess the longer overall cooling trend.”
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