LCS-FY2021-SR-01
[Survey Report] Toward Future Low-Carbon Society using Scrap Iron Recycling:
Use of recycled steel and CO2 emissions in venues of the 2020 Tokyo Games
Summary
In recent years, the Olympic Games have been managed with consideration for the environment, and the efforts toward reducing CO2 to prevent global warming are being made. Steel is an essential material for construction, but it is also a material with high CO2 emissions during manufacturing.
Therefore, we decided to compare the amount of steel used in the construction of facilities for Tokyo and other Olympic Games, the percentage of recycled steel with low CO2 emissions, and the amount of CO2 emissions. Also, we examined the effectiveness of the checklist developed by the Tokyo Metropolitan Government.
The amount of steel used in all sports facilities at the Tokyo Olympic Games was 124,000 tons, and CO2 emissions were 162,000 tons, compared to 35,000 tons and 62,000 tons at the London Games. Comparing Tokyo Stadium with other stadiums (London, Beijing and Sydney), Tokyo Stadium had the second highest steel usage after Beijing Stadium (100,000 tons). It is because that Japan is an earthquake-prone country, and the Tokyo Stadium was designed to be earthquake-resistant, with a large roof and a complex structure.
Tokyo's facilities (not including the stadium) to which applied the checklist had a steel volume of 55,000 tons and CO2 emissions of 59,000 tons. And the percentage of recycled steel used was high at 62% and emissions per unit steel volume of 1.08 tCO2/t. It was lower than the London Games' 1.77 tCO2/t.
The "Tokyo Metropolitan Government Checklist of Planned (Actual) Use of Environmental Products" was found to be effective in encouraging the use of recycled steel and reducing emissions. It is desirable that future Olympic host cities apply such a "checklist" to all facilities. In the future, the use of the "checklist" at largescale construction sites in Japan will prove useful in reducing CO2 emissions.