The Ministry of Education, Culture, Sports, Science and Technology has devised a new method for rapidly estimating the impact of global warming on the probability of occurrence of extreme weather events (hereafter referred to as "extreme events"). A bulletin reported that the effects of global warming had contributed greatly to the record high temperatures.
This research, in collaboration with the Ministry of Education, Culture, Sports, Science and Technology's Climate Change Prediction Advanced Research Program and the Meteorological Research Institute of the Meteorological Agency, will quantify the impact of anthropogenic global warming on the probability and intensity of extreme weather events that have occurred frequently in recent years. It is one of the researches of “Event Attribution (EA)”.Previously, EA used climate models to compare warmed and non-warmed climate conditions through a large number of simulations, which took months to produce results.Therefore, in order to be able to quickly disseminate information, we will utilize the numerous calculation examples accumulated in the "Ensemble Climate Prediction Database Contributing to Global Warming Countermeasures", and also apply boundary conditions (sea surface temperature, sea ice conditions, etc.) to the model. We devised a new predictive EA method that obtains from the 3-month forecast data of the Japan Meteorological Agency.With this method, it is possible to prepare a large amount of simulations necessary for EA in advance, and it has become possible to greatly reduce the time it takes to transmit information.
As a result of applying this method to the record-breaking high temperature event from late June to early July 4, the probability of occurrence increased to 6% due to the combined effects of La Niña and other phenomena in Japan during this period. I found out.On the other hand, if the effects of global warming were removed, the probability of occurrence of this high temperature event was 7%.In other words, the probability of occurrence of a once-in-19.8-year event, which would have been extremely rare without human-induced global warming, had risen to a frequency of about once every five years under this summer's conditions.
In this way, the predictive EA method has made it possible to quickly assess the impact of global warming and disseminate information after the occurrence of an extreme event. It also plans to promote measures to adapt to climate change.
