Flooding in Germany - its probability increases up to 9 times due to climate change - international research

Recently CNN.co.jp reported the following:

ドイツ大洪水、気候変動で確率が最大９倍に上昇　国際研究

2021.08.24 Tue posted at 19:30 JST

 ロンドン（ＣＮＮ） ドイツなど西欧に先月、大規模な洪水をもたらした豪雨は、気候変動の影響で確率が１．２～９倍に上昇した結果起きたとする研究結果が報告された。

気候変動の影響を分析する国際プロジェクト「世界気象アトリビューション（ＷＷＡ）」の科学者ら３９人が、先月１２～１５日に２２０人以上の死者を出した水害について調べた。

大規模な集中豪雨は４００年に１度の現象だったこと、１日の雨量は気候変動のために３～１９％増加していたことも明らかになったという。

英オックスフォード大学環境変動研究所のフリードリク・オットー副所長は「先進国も異常気象の影響を免れないことが、この洪水で分かった」と指摘する。

オランダ・トゥウェンテ大学のマールテン・ファンアールスト博士によると、４００年に１度というのは対象地域での頻度（ひんど）で世界のほかの地域で今後４００年、同じようなことが起きないという意味ではない。気候変動は年々進んでいるため、異常気象のリスクも年ごとに増大すると予想される。

研究者らはドイツやベルギーの川沿いのほかにフランスやオランダ、ルクセンブルク、スイスの状況も考慮し、コンピューター・シミュレーションを使って、産業革命前の１８００年代後半と、当時より気温が１．２度上昇した現在を比較した。これに基づき、気温が産業革命前より２度上昇した場合は、豪雨発生の確率がさらに１．２～１．４倍に上昇し、１日の雨量がさらに０．８～６％増加すると予想している。

ファンアールスト博士は「私たちにできるのは、リスクがますます手に負えなくなる事態を防ぐために温室効果ガスの増加を止めること、その一方でさらなる異常気象に備えることだ」と語った。

Translation

 London (CNN) - Last month, a study had reported that the heavy rains that caused large-scale flooding in Western Europe such as Germany were the result of a 1.2-fold to 9-fold probability increase due to the effects of climate change.

In an international project that analyzed the effects of climate change, thirty-nine scientists from the “World Meteorological Attribution (WWA)” investigated flood damages that killed more than 220 people on the 12th to 15th of last month.

It was also revealed that this large-scale torrential rain was a phenomenon that happened once every 400 years, and that the daily rainfall increased from 3% to 19% due to climate change.

Friederike Otto, the deputy director of the Institute for Environmental Change at the Oxford University said, "The floods have shown that developed countries are not immune to extreme weather events too".

According to Dr. Maarten van Aalst of the University of Twente in the Netherlands, once every 400 years would be a frequency of a specifically targeted area, and it didn't mean the same would not occur in another part of the world in the next 400 years. As climate change progressed yearly, the risk of extreme weather events was expected to increase every year.

Researchers had, on top of along the rivers in Germany and Belgium, also taken into account the situation in France, the Netherlands, Luxembourg and Switzerland, and used computer simulations to compare the latter half of the 1800s before the Industrial Revolution with the present when the temperature rose 1.2 degrees since that time. Based on this, if the temperature rose 2 degrees from before the Industrial Revolution, the probability of heavy rainfall could further increase by 1.2 to 1.4 times, and the daily rainfall would further increase by 0.8 to 6%.

Dr. Maarten van Aalst said, " In order to prevent the risk from becoming increasingly unmanageable, what we can do is to stop the increase in greenhouse effect and prepare for more extreme weather at the same time".

So, a study has showed that the heavy rains that caused large-scale floods in Western Europe such as Germany were the effects of climate change, and to stop an increase in greenhouse effect will be the only way out.