Abstract
Sea level rise and an increase in typhoon intensity are two of the expected consequences from future climate change. In the present work a methodology to change the intensity of tropical cyclones in Japan was developed, which can be used to assess the inundation risk to different areas of the country. An example of how this would affect one of the worst typhoons to hit the Tokyo Bay area in the 20th century was thus developed, highlighting the considerable dangers associated with this event, and how current sea defences could be under danger of failing by the end of the 21st century. The present results show how this level of defences could be inadequate by the end of the 21st century. Possible solutions to this problem involve raising the level of existing defences or increasing the ground level of reclamated area. The cost of possible countermeasures are calculated and are compared with possible economic loss under flooding. The cost is less than 1 % of possible economic loss in Tokyo metropolitan and 6 % in Kanagawa prefecture.