Intensive heavy rainfall and dry days likely to increase

Overview

A research group formed by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Meteorological Research Institute and Hokkaido University has carried out large number high-resolution warming simulations using JAMSTEC’s Earth Simulator supercomputer, focusing on a near-future (~2030–2050) climate change state characterized by a global average surface air temperature increase of 2 °C since the Industrial Revolution. Their analysis results showed a high possibility of extreme precipitation (annual maximum daily precipitation) events increasing in intensity in the near future even with successful implementation of international efforts geared at the mitigation and suppression of global warming based on the Paris Agreement (Figures 1 and 2). The results have also projected an increase in the number of consecutive dry days (Figure 2).

Increases in precipitation have accompanied progressive warming to the present time and rainfall phenomena have been reported as becoming more extreme. Evaluating the extent to which low-frequency (every few decades) extreme meteorological phenomena will change in the future is vital for ensuring the production of highly accurate projections necessary for determining climate change adaptive measures in natural disaster prevention, agriculture, and other areas. The near-future climate forecast database created for this study will be useful for assessing evaluation and adaptation measures related to various extreme phenomena (not limited to rainfall).

This study project has been supported by the Social Implementation Program on Climate Change Adaptation Technology (SI-CAT). The above results were published in Geophysical Research Letters on January 10, 2019 (JST).

The above results were published in Geophysical Research Letters on January 10, 2019 (JST).
https://doi.org/10.1029/2019GL079885

Figure 1. Average rate of precipiation change comparing near-future climate (~2030–2050) to past climate (1951–2010): (a) Annual daily average precipitation and (b) Annual-maximum daily precipitation. Diagonal hash marks represent regions for which data are not statistically supportive.

Figure 2. Average rate of change (dots) and margin of error (error bars) for the global average of future climates (near future, ~2030–2050; end of century, ~2070–2090) contrasted with past climate (1951–2010) calculated individually for both rainy (blue) and dry (red) seasons: (a) Average daily precipitation, (b) Annual-maximum daily precipitation, and (c) Number of consecutive dry days.