While the Kawasaki waterfront area is one of the largest industrial complexes in Japan and the center of industry in Kawasaki City, it is also a major source of carbon dioxide emissions. To strategically promote hydrogen-related initiatives, Kawasaki City formulated the “Kawasaki Hydrogen Strategy for Realizing a Hydrogen Society” in 2015, ahead of the rest of the country, and has been promoting initiatives to realize “future-type environmental and industrial city” by actively introducing and using hydrogen energy. Furthermore, in light of the global trend toward decarbonization and carbon neutrality, Kawasaki formulated the “Kawasaki Carbon Neutral Industrial Complex Concept” in 2022, and has been working to transform itself into an industrial complex that can adapt to and contribute to a carbon-neutral society.

The Ishikari City has been selected by the government as a “Leading Decarbonization Region,” a region that is taking advanced local decarbonization initiatives to achieve carbon neutrality in 2050. Facing the Sea of Japan, the city has a concentration of renewable energy sources （“renewable energy”）, mainly wind power generation, due to favorable wind conditions and vast land. This paper introduces the city’s efforts to achieve “local production for local use” of renewable energy by utilizing the renewable energy sources concentrated in the region.

As the need for further acceleration of climate change countermeasures increases, efforts to reduce greenhouse gas supply chain emissions are progressing in various industrial sectors. In this context, small and medium-sized enterprises （SMEs）, which account for not a small proportion of Japan’s greenhouse gas emissions, may become a bottleneck. Under these circumstances, Toyota City, which has formed an automobile-related industrial cluster, etc. are taking steps to promote decarbonized management, mainly targeting small and medium-sized enterprises. This paper summarizes these trends and discusses future issues in calculating and reducing supply chain emissions.

The purposes of this article are to report on efforts toward decarbonization of domestic and foreign industries in industrial parks, and to share with readers an image of future implementation in Japan. Through a demonstration project, the author divided the application method of the incineration heat industrial use in the case of cooperation with the material industry and with the local manufacturing industry in the regional circulation symbiotic sphere models with incinerators as the core. In the materials industry collaboration model, incinerators are expected to become carbon recycling plants in the future. Overseas, there are multiple examples of industrial use of incineration heat in collaboration with materials industries, and so this article introduces some of them. We also presented the results of a survey on wide-area transportation, which is an important perspective for implementation. In addition, I introduced the efforts of the “Transitioning Industrial Clusters initiative” led by the World Economic Forum. Industrial clusters are considering green hydrogen, H/CO₂ pipelines, renewable energy, incineration heat supply to industry, chemical recycling, electrification, and joint wastewater treatment as decarbonization measures. To make this a reality, it is necessary to improve partnerships, policies, technology, and finance. In Japan, it was considered that promoting carbon neutrality in industrial parks are necessary with refer to these overseas trends by building collaborations within the country.

The purpose of this article is to report on trends toward decarbonization in industrial parks by industrial symbiosis and eco-industrial parks. First, it describes their position in recent trials and introduced a related symposium and site visit in 2023 in Ulsan. We then outline the efforts of South Korea, a leading example of an eco-industrial park, and introduce the supporting initiatives of international organizations. We indicate that not only each individual park effort, but also collaboration with other industrial parks and international partnerships are important to realize decarbonize industrial complexes.

Fish and other marine products are transported in refrigerated or frozen temperature zones until they reach the consumer. Still, at the time of consumption, the fish meat must be thawed, and the increase in temperature of the fish meat may cause a significant loss of freshness due to the coarsening of ice crystals and enzymatic reactions. When assuming general household consumption, microwave, room temperature thawing, refrigerated thawing, submerged thawing, or running water thawing are candidates for standard thawing methods in the home. Since direct and indirect energy inputs that affect environmental impact are used during thawing, the environmental impact differs depending on the thawing process, and it is assumed that there is an interrelationship between quality and environmental impact. Therefore, in this paper, a combined evaluation of five thawing methods for frozen mackerel was conducted, combining the freshness of fish meat by the electrical impedance measurement and environmental impact based on LCA. Because the dripping water from the mackerel, depending on ambient temperature and residual time, flows out. In the environmental impact assessment, GWP （GHG emissions） was used as the evaluation index, and the functional unit（FU） was assessed as 60 g of edible portion of approximately one mackerel fillet until it was thawed.

Consequently, the impedance is affected. From the viewpoint of freshness, it was suggested that quality was maintained by thawing the fish over a more extended period while keeping the temperature low. This is because lower temperatures slow down the breakdown of cells during thawing and slow down the deterioration of meat quality. Impedance measurements were made at a voltage of 50 mV and a frequency range of 100 kHz to 10 Hz. 100 Hz results showed that the smallest impedance was 40.8 Ω during flow-thawing.

In contrast, the thawing method with the highest impedance was refrigerated thawing at 69.0 Ω. In addition, the environmental impact （GHG emissions） considering thawing time and direct and joint energy input was the highest for running water thawing at 14.2 g-CO₂ eq./FU. This is due to the high indirect energy consumption from water consumption. The other thawing methods were 0.124 g-CO₂ eq./FU for refrigerated thawing, 0.196 g-CO₂ eq./FU for submerged thawing, and 0.005 g-CO₂ eq./FU for microwave thawing.

Finally, a combined evaluation of the environmental impact and freshness of mackerel using microwave thawing as the base case suggested that refrigerated thawing was preferable to room temperature thawing in terms of maintaining freshness.

EcoBalance 2022 took place in Fukuoka, Japan between 30 October and 2 November 2022. This report presents a brief summary of the conference including plenary talks, organized sessions, oral sessions, and EcoBalance awards. An overview and a future prospect of the conference are also mentioned.