In recent years, we have witnessed the unavailability of Pacific saury, and poor catches in Hokkaido spiking the price of salmon roe. Both cases have been attributed to the rising temperature of the ocean.

When the global temperature rises, the oceans absorb the excess heat; and when sea water temperatures rise, water vapor is generated from the ocean. This water vapor cools in the sky, forming clouds, and generating rain. The higher the atmospheric temperature, the higher the sea water temperature, the more water vapor is generated, and the larger the clouds. The recent increase in the size of typhoons has been put down to global warming. Seawater also absorbs carbon dioxide from the air, but as the water temperature rises, it is less able to do so, and conversely, the captured carbon dioxide is released into the air. In other words, the concentration of carbon dioxide in the air will become even higher, which, in turn, will accelerate global warming.

Over the last few years, we've come to hear the term "linear precipitation zone” in relation to news of heavy rains that are devastating many regions around the world. Rain clouds form into a series, producing concentrated rainfall, and triggering once-in-a-decade or once-in-a-century downpours that can cause landslides and flooding that result in great damage. Still fresh in the memory is the Kuma River overflowing its banks in July 2019, causing great damage in Hitoyoshi City, Kumamoto Prefecture, and elsewhere in Japan. Many experts believe that the occurrence of linear precipitation zones, which cause record-breaking heavy rainfall, is also a result of global warming. As the oceans warm up due to global warming, typhoons will become larger in size, intensifying the impact of climate change, and threatening our lives and livelihoods.

episode 3
Global Warming is Heating the Ocean and Generating Storms

Detailed Data and Explanation 1:
Japan's oceans are warming up.

Source: Japan Meteorological Agency website
https://www.data.jma.go.jp/gmd/kaiyou/data/shindan/a_1/japan_warm/japan_warm.html

The graph above shows the rise in seawater temperature over the approximately 100 years up to 2020. The seawater temperature has risen by 1.16 ° C in the last 100 years, almost double the estimated 0.56 ℃ increase in the Earth’s temperature. Demonstrably, the seas surrounding Japan are experiencing a high rate of increase in water temperature when compared to global warming as a whole.