Research press release


Scientific Reports

Climate change: Frequency of extreme droughts across Europe predicted to rise

温室効果ガス排出量が計画どおり削減できなければ、21世紀末には、2018~2019年に中央ヨーロッパで発生したような記録破りの2年連続の干ばつの発生頻度が、今よりも上昇するという予測を示した論文が、Scientific Reports に掲載される。

今回、Vittal Hariらの研究チームは、1766~2019年の長期世界気候データを用いて、2018~2019年の中央ヨーロッパの干ばつの影響を調べた。その結果、2018年と2019年の夏は、降水量がいずれも平均値を下回り、観測記録上最も暑かった3度の夏のうちの2度に該当することが明らかになった。2018年と2019年の夏は、中央ヨーロッパ地域の50%以上が極度の干ばつに見舞われ、観測記録上、最大規模で、最も影響の大きい2年連続の干ばつとなった。2番目に影響の大きかった干ばつは、1949年から1950年まで続いたが、影響を受けた地域の面積は33%小さかった。




The frequency of record-breaking two-year droughts, such as the 2018–2019 Central European drought, is expected to rise by the end of the century if projected greenhouse gas emissions are not reduced, according to a study published in Scientific Reports.

Vittal Hari and colleagues examined the impact of the 2018–2019 Central European drought using long-term global climate data from 1766 to 2019. They found that the summers in both 2018 and 2019 were drier than average, and were two out of three of the warmest summer periods ever recorded. More than 50% of the Central European region suffered severe drought conditions, making it the largest scale and most impactful two-year drought on record. The second most impactful drought recorded lasted from 1949–1950, but affected a 33% smaller area.

The authors used global climate change computer models to predict how the frequency of two-year droughts may change in the coming decades and whether greenhouse gas emissions may have an effect. When modelling climate scenarios predicting the highest increase of greenhouse gases over time, the authors projected a seven-fold increase in the number of two-year droughts across Europe in the second half of the century (2051–2100). The projections also suggested that drought-affected cropland areas across Central Europe will nearly double, including more than 40 million hectares of cultivated land.

When climate projections of moderate greenhouse gas concentrations were used, the predicted number of two-year droughts reduced by almost half. The expected frequency decreased by over 90% when low climate projections were used. The amount of drought-prone areas reduced by 37% and 60% when using climate models with moderate and low emissions, respectively.

The findings indicate that introducing measures to reduce future carbon emissions may lower the risk of more frequent consecutive drought events across Europe.

doi: 10.1038/s41598-020-68872-9


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