In the summer of 2018, high temperatures broke records in central Europe; at the same time, low summer precipitation led to extreme drought conditions. The impact on plant and agricultural productivity was severe in a region with a strong focus on agriculture, and propagated to 2019.
A new study using long-term historical data has found that the 2018-2019 two-year drought in central Europe was unprecedented in the last 250 years, with substantial implications for vegetation health, and has looked into future drought risk under different climate scenarios, informs Phys.org.
In the past two decades, the frequency of droughts has increased in Europe. In the case of exceptionally hot and dry years 2003 and 2015, vegetation health recovered in the following years. However, the impact of the 2018 drought on vegetation is still underway, according to the study, published in the Nature journal Scientific Reports.
The researchers then estimated the occurrences of two-year droughts under different global warming scenarios in the future, including higher (Representative Concentration Pathway (RCP) 8.5) and moderate (RCP 4.5) greenhouse gas concentrations, associated with different levels of emissions.
Based on the results form climate model simulation, under the RCP 8.5 scenario ─ if emissions continue to rise throughout the 21st century, or business as usual ─ the study estimates a seven-fold increase in the number of two-year drought events after 2050. Drought affected cropland in central Europe would nearly double in comparison to historical values, affecting 40 million hectares of cropland (60% of the total cultivated area in central Europe).
A reduction to moderate emissions would decrease the risk of dry periods, with half the number of two-year droughts and a reduction in the area affected by drought.
Researchers believe a two-year drought poses a greater risk to vegetation health than one dry summer since the land takes longer to recover. In central Europe, more than 34% of the land area is used for agricultural purposes. The study authors believe "it is with the utmost urgency that we need to recognise the importance of these persevering consecutive year events, and to develop a holistic framework to model the risk".