Under the UNFCCC, the ocean did not receive sufficient attention, but thanks to the activities of the ocean community the Ocean and Climate Change Dialogue was established and has since become a forum for deepening discussion. Attempts are also being made to increase the presence of the ocean, such as the establishment of an ocean pavilion. In order to protect the ocean and combat climate change in these difficult times, it is essential to first increase the ambition of each country's NDCs, including those of Japan, and to strengthen ocean-related initiatives.

We estimated the damage caused by potential inundation in each prefecture due to sea level rise and tides for coastal areas of Japan. Furthermore, when comparing the results based on greenhouse gas emission pathways, the damage amount varied between approximately 218.0 and 576.8 trillion yen, suggesting the importance of mitigation measures. In examining adaptation measures to sea level rise, it became clear that since there are inundation prone areas where much of the flooding impact could be protected with little adaptation cost, it was shown that limiting protection to those areas would be effective.

Blue carbon through seaweed cultivation has great potential for Japan, which has a long coastline. Use offshore wind power generation facilities would be effective since there are many challenges in establishing new cultivation facilities close to the shore, however, care must also be taken not to disturb the local biodiversity. In these circumstances, it is expected that new seaweed species will be cultivated that are different from those used for fisheries, so we propose the use of culture collections to collect and preserve strains of various seaweed species.