Editing IPCC:AR6/WGI/Chapter-11 (section)

==== 11.7.3.4 Detection and Attribution, Event Attribution ====

<div id="h3-42-siblings" class="h3-siblings"></div>

It is extremely difficult to detect differences in time and space of severe convective storms ( [[#Kunkel--2013|Kunkel et al., 2013]] ). Although some ingredients that are favourable for severe thunderstorms have increased over the years, others have not; thus, overall, changes in the frequency of environments favourable for severe thunderstorms have not been statistically significant. Event attribution studies on severe convective events have now been undertaken for some cases. For the case of the heavy rain event of July 2018 in Japan (Box 11.4), [[#Kawase--2020|Kawase et al. (2020)]] took a storyline approach to show that the rainfall during this event in Japan was increased by approximately 7% due to recent rapid warming around Japan. For the case of the December 2015 extreme rainfall event in Chennai, India, the extremity of the event was equally caused by the warming trend in the Bay of Bengal SSTs and the strong El Niño conditions ( [[#van%20Oldenborgh--2016|van Oldenborgh et al., 2016]] ; [[#Boyaj--2018|Boyaj et al., 2018]] ). For hailstorms, such as those that caused disasters in the USA in 2018, detection of the role of climate change in changing hail storms is more difficult, because hail storms are not, in general, directly simulated by convection-permitting models and not adequately represented by the environmental parameters of coarse-resolution GCMs ( [[#Mahoney--2020|Mahoney, 2020]] ).

In summary, it is extremely difficult to detect and attribute changes in severe convective storms. There is ''limited evidence'' that extreme precipitation associated with severe convective storms has increased in some cases.

<div id="11.7.3.5" class="h3-container"></div>

<span id="projections-5"></span>