[Column Series] Key Issues to Address in Japan's Strategic Energy Plan (No.5) Are Japan’s Emission Reduction Efforts Really “On Track”? (Part 2)

in Japanese

In the column entitled “Are Japan’s emission reduction efforts really ‘on track’?” published on 19 July 2024 (in Japanese), I expressed my concern that presenting only the short-term trends that occurred due to the extraordinary circumstances following the Fukushima Daiichi Nuclear Power Plant accident and using this data to claim that Japan’s emission reductions are “on track,” while those of other countries have “derailed” does not lead to a constructive discussion of the issues at hand. A researcher who read the article subsequently pointed out that in addition to the points I raised, there are other critical issues in the government’s explanation that Japan’s emission reduction efforts are “on track.” As these have not been addressed previously, I would like to provide further explanation in this column.

Oddities in the “On Track” Scenario Graph Presented by the Japanese Government

Figure 1, presented at the Strategic Policy Committee on 15 May 2024, shows “Japan’s progress in reducing CO₂ emissions.” The graph consists of a blue bar showing CO₂ emissions, a short green bar showing CO₂ absorption (by forests), and a black line showing net emissions (emissions minus absorption).

Upon closer inspection of this graph, an odd detail is worth highlighting. For some reason, the green bar which shows the amount of absorption, is not plotted for FY 2013, the base year, nor is the black line representing net emissions. Furthermore, the red dotted line representing the reduction trend, which illustrates the government’s key “on-track” scenario, starts from the top of the blue bar representing emissions in FY 2013 and passes through the black dotted line indicating net emissions in FY 2022.

　Figure 1: Oddities in the “on track” scenario graph presented by the Japanese government

In other words, the red dotted line, which claims to show the reduction trend, runs through two different categories of figures: total emissions in FY 2013 and net emissions in FY 2022. This is not a plotting error—it is a faithful representation of the story that the government wants to depict. Why is this so?

The Japanese Government’s Calculation Method Artificially Raises the Base from which Actual Reductions are Calculated

The Japanese government’s Nationally Determined Contribution (NDC) targets for FY 2030 are, in fact, based on a unique method in which figures for FY 2013, the base year, are based on gross emissions without subtracting forest carbon sinks, while figures for subsequent years are based on net emissions, where forest carbon sinks are subtracted from gross emissions. This does not mean that forest carbon sinks were zero in FY 2013, but rather that they are not included in the calculations. As a result, because forest carbon sinks are added to the emission reduction performance from FY 2014 onwards, reductions are boosted by this method, making the reduction rate appear higher than it actually is. This method of calculation is known as the gross net method¹, and has been adopted by the Japanese government since the Kyoto Protocol era. Japan is currently the only developed country that applies this method.

What would the trend look like if we subtracted forest carbon sinks from gross emissions and examined the reduction trend based on emissions/absorption (net emissions) for both FY 2013, the base year, and for FY 2022, the most recent year? This analysis is shown in Figure 2.

　Figure 2: Japan’s emission reductions are not “on track” once this artificial booster effect is removed

The green dotted line shows the long-term trend after removing the booster effect of excluding the forest carbon sinks in FY 2013 and extending the trend of net emissions reductions to FY 2050 (this data has been added to Figure 1 in the 19 July column, which shows the trend line from FY 1990). The trend in emissions reductions slows down as the magic of this artificial booster effect disappears and emissions do not reach zero even in FY 2050. This graph suggests that approximately 400 million tons of emissions will remain at that point.

The Climate Action Tracker, an independent science-based body that tracks and assesses national NDCs, has criticized Japan for using the gross net method, stating that it “undermines the purpose of the Paris Agreement”².

Actual Reduction Since FY 2013 is less than Half of Government's Claim

In my previous column, I pointed out that the reason that Japan’s emission reductions since FY 2013 appear to be on track is largely due to extraordinary circumstances, namely the increase and subsequent improvement in the CO₂ emission factor in the power generation sector following the Fukushima Daiichi Nuclear Power Plant accident. In addition to this, the exclusion of base year CO₂ absorption was another piece of “magic” that made Japan’s emission reductions appear to be on track. According to the GHG emissions data (final figures) for FY 2013 released by the Ministry of the Environment, the amount absorbed during that year was 61 million tons³. The reduction resulting from improving the CO₂ emission factor following the nuclear power plant accident discussed in the previous column, is at least 100 million tons. Together, these add up to more than 160 million tons—more than half of the 322 million tons in GHG reductions from the base year in FY 2013 to 2022, the period the government refers to in its “on track” claim.

It would be unreasonable to state that Japan’s emission reductions are on track while other developed countries are struggling to reduce their emissions without any explanation whatsoever of these underlying factors.

Achieving the emission reductions needed to meet the 1.5°C target proposed by the IPCC is no easy task for any country. In particular, European countries that have been leading the transition to a decarbonized energy system, are currently facing several challenges, largely due to the energy crisis triggered by Russia’s invasion of Ukraine.

However, it is important to correctly assess the progress made by European countries, which are ahead of Japan in implementing the key steps needed to transition to a decarbonized economy, including phasing out coal-fired power, integrating renewables, decarbonizing industries such as the steel, and introducing carbon pricing. Japan will not succeed in achieving the policy reforms that are now needed if it continues to insist that “Japan is not lagging behind” without making an objective assessment of its own performance.

[Special Contents] Key Issues to Address in Japan's Strategic Energy Plan