ABSTRACT
Previous agriculture-climate and meteorological studies have usually been based on standard climatology data, obtained from 30-y periods. Most often the World Meteorological Organization has recommended two such periods: 1961-1990 and 1971-2000. In the latter period, and more precisely in the last two decades, climatologists in Poland have observed the highest increase in temperature thus far. The thermal and pluvio-thermal conditions at the end of this period (accounting for significant temperature increase) have deviated from the 30-y average. In light of further increases in temperature during the beginning of the twenty-first century some researchers claim that the 1971-2000 data cannot be used for analysis in subsequent years. Therefore, we postulate that any agrometeorological calculation should be based on the new climate features, and not previous climate standards, which are referred to as mean values from past years (Górski 2002, Milly et al. 2008).
