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Japan’s carbon neutrality challenge

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A dense layer of smog covers the Japanese capital, Japan, 13 January 2021 (Stanislav Kogiku / SOPA Images/Sipa USA via Reuters Connect)

In Brief

As the world enters the implementation phase of the Paris Agreement, countries are increasingly under pressure to announce their 2050 carbon neutrality goals and update their Nationally Determined Contributions (NDCs) for 2030. As of March 2021, more than 120 countries have pledged carbon neutrality by 2050. Last October, former prime minister Yoshihide Suga announced that Japan would aim to achieve carbon neutrality by 2050.


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Three months before Suga’s announcement in July 2020, Japan entered a process of formulating the Sixth Strategic Energy Plan, which seeks to introduce new energy sources that will underpin its new NDC. A cabinet-approved version was submitted at the COP26 Summit in Glasgow.

Formulated in 2015, Japan’s previous NDC pledged a 26 per cent reduction of greenhouse gas (GHG) emissions from 2013 levels by 2030. Under this target, Japan’s total power generation was made up of a 44 per cent share of non-fossil fuels (22–24 per cent from renewables, 20–22 per cent from nuclear). This energy mix fulfilled three requirements: restoring energy self-sufficiency to around 25 per cent (surpassing pre-2011 Fukushima disaster levels), lowering electricity costs and setting a GHG reduction goal that was comparable with other developed countries. This NDC was designed to reduce fossil fuel imports and accelerate the adoption of renewable energy through Japan’s Feed-In Tariff (FIT) policy.

The 2030 target was formulated based on a bottom-up approach. The 2030 GHG emissions target was to be pursued with certainty, as it was calculated against existing policies and technologies. On the other hand, the 2050 goal was based on a top-down approach and committed Japan to an 80 per cent reduction in GHG emissions. It was regarded as a ‘vision’ or ‘aspirational direction’ amid multiple uncertainties. The differentiated use of the words ‘target’ and ‘goal’ further reflect the nature of these approaches.

Despite this, raising the 2050 goal from an 80 per cent reduction to carbon neutrality has almost eliminated these differences. At the 2021 Leaders’ Climate Summit hosted by the United States in April, prime minister Suga announced that Japan would aim for a 46 per cent reduction from 2013 levels by 2030 and continue strenuous efforts to meet a 50 per cent reduction. This target is not based on a bottom-up approach.

At the time of this pledge, discussions of a new energy mix were still underway. The Japanese Ministry of Economy, Trade and Industry (METI) allegedly advised Suga that the new target should be lower than a 40 per cent reduction, judging from progress towards Japan’s previous target. Still, Suga and Environment Minister Shinjiro Koizumi insisted on a figure close to 50 per cent for the sake of ‘consistency’ with Japan’s 2050 carbon neutrality goal. They also faced pressure from the United States and the United Kingdom as the COP26 Chair.

In other words, Japan’s bottom-up approach was replaced by a top-down approach. This implies that the 2030 target — set simply by linear back-casting from the 2050 goal — has come to be characterised by its aspirational and visionary nature. The non-binding nature of the NDC may have made it easier for Japan to support this more ambitious goal.

In July 2021, METI proposed a draft of the Sixth Strategic Energy Plan with a new energy mix in 2030 where non-fossil fuels will account for 56–60 per cent of Japan’s total power generation (36–38 per cent from renewables, 22–20 per cent from nuclear). Compared with the previously proposed energy mix, the share of renewable energy was substantially raised, while the share of nuclear was maintained. In addition, projected total power generation in 2030 was lowered from 980 GWh to 870 GWh.

These figures have been criticised as ‘playing a mathematical game’ and their feasibility is questionable. A higher share of renewables will increase the cost of feed-in-tariff (FIT) subsidies from 4 trillion yen (US$35 billion) to 6 trillion yen (US$53 billion), not including the additional costs of integrating intermittent renewable energy sources into the power system. The majority of flat areas suitable for solar power plants have already been exploited. Despite high expectations for offshore wind power, wind conditions in the seas surrounding Japan are not as favourable as those in the North Sea. Restarting nuclear power plants has been slower than expected.

Japan’s energy costs are the biggest concern. Japan’s marginal abatement cost for reducing GHG emissions is much higher than other developed countries. Japan’s industrial electricity tariff is already the highest among major countries, being two times that of nations such as the United States, China and South Korea. While METI assumes lower fossil fuel costs, partly compensating higher costs for subsidising renewable energy, ongoing fossil fuel price hikes make this assumption questionable. The Japanese government needs to regularly review the cost of implementing this energy mix and compare it with its major trading partners. Otherwise, the international competitiveness of Japanese manufacturing industries may be at risk.

If Japan is serious about reaching carbon neutrality by 2050, the construction of new and more advanced nuclear power plants is essential. Nuclear energy has its own challenges, namely widespread ‘nuclearphobia’ and soaring initial investment costs. For addressing the latter problem, regulated asset base policies deserve consideration.

The ruling Liberal Democratic Party has vowed to introduce Small Modular Reactors (SMR), which could make nuclear installation much more affordable. ‘Nuclearphobia’ is the most challenging part. While geopolitical and geoeconomic risks soar — and while Japan deepens its dependence on solar and wind energy, and inflows of Chinese panels, windmills and batteries — nuclear technologies deserve renewed attention.

Jun Arima is Professor at the Graduate School of Public Policy, the University of Tokyo. He is a former Japanese official and chief negotiator to the United Nations Framework Convention on Climate Change.

2 responses to “Japan’s carbon neutrality challenge”

  1. By using the term ‘nuclearphobia’ the author is trying to discount what are legitimate concerns that members of the scientific community and the public have about the safety of nuclear power. More specifically, the storage of spent fuel in large pools of cooled water is risky at best. Actually, the events at Fukushima in March 2011 have proven to many that today’s nuclear power plants are dangerous at worst. None of the plant owners nor the Japanese government have been willing to invest in the safer storage of the spent fuel in cement casks. No one seems to show any interest in doing this.

    History has proven that promises of better cost containment of the construction of nuclear power plants are proven wrong. Costs have ALWAYS been much higher than the initial estimates. The same will probably be true for the next generation of SMR’s.

    Furthermore, the Union of Concerned Scientists have published a report which notes that these reactors do not offer much more safety than existing ones. The issue of long term safe storage of spent fuel would still be a major stumbling block. FYI, UCS is a nonpartisan organization of scientists with expertise in this field.

    Finally, I agree that reliance on China for solar panels, windmills, and batteries is not good policy. Japan has the engineering and manufacturing capabilities to develop these industries domestically. Why not invest in a future that will not depend on nuclear power at all?!? Japan could even export these elements of a solar and wind power industry. THAT would give a boost to economy. And it would also allow Japan to be a world leader in a significant way.

  2. I have to agree with the comments of Richard Solomon on this post regarding nuclear power. It remains a very expensive energy technology on balance that have not moved on significantly since its development in the previous century. There are still major risks and problems with nuclear fission plants, and almost every country that has nuclear has been divesting in this sector in net capacity terms since the beginning of this century (see past World Nuclear Reports).

    Solar, wind and other renewable energy techs offer the best future-proof options for any national energy strategy on the power generation side. More investment in smart grid infrastructure is needed in Japan to integrate renewables. I am surprised the article made no mention of green hydrogen, which is vital on the industrial thermal energy side – where Japan has both the capacity and need to develop. Thermal heat energy accounts for 50% of total primary energy consumption worldwide, power generation (electricity) 20%, and transportation 30% – where Japan’s pioneering automobile manufacturers are trying to advance electric vehicle tech, but mainly on car vehicles.

    There needs to be, though, an alignment of political and industrial lobby will in order for Japan to develop a more viable long-term energy strategy based on renewables and energy technologies of the 21st century, not the 20th century.

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