Jusen Asuka

Comparative assessment of Japan's long-term carbon budget under different effort-sharing principles

This article assesses Japans carbon budgets up to 2100 in the global efforts to achieve the 2 °C target under different effort-sharing approaches based on long-term GHG mitigation scenarios published in 13 studies. The article also presents exemplary emission trajectories for Japan to stay within the calculated budget. The literature data allow for an in-depth analysis of four effort-sharing categories. For a 450 ppm CO2e stabilization level, the remaining carbon budgets for 2014–2100 were negative for the effort-sharing category that emphasizes historical responsibility and capability. For the other three, including the reference ‘Cost-effectiveness’ category, which showed the highest budget range among all categories, the calculated remaining budgets (20th and 80th percentile ranges) would run out in 21–29 years if the current emission levels were to continue. A 550 ppm CO2e stabilization level increases the budgets by 6–17 years-equivalent of the current emissions, depending on the effort-sharing category. Exemplary emissions trajectories staying within the calculated budgets were also analysed for ‘Equality’, ‘Staged’ and ‘Cost-effectiveness’ categories. For a 450 ppm CO2e stabilization level, Japans GHG emissions would need to phase out sometime between 2045 and 2080, and the emission reductions in 2030 would be at least 16–29% below 1990 levels even for the most lenient ‘Cost-effectiveness’ category, and 29–36% for the ‘Equality’ category. The start year for accelerated emissions reductions and the emissions convergence level in the long term have major impact on the emissions reduction rates that need to be achieved, particularly in the case of smaller budgets. Policy relevance In previous climate mitigation target formulation processes for 2020 and 2030 in Japan, neither equity principles nor long-term management of cumulative GHG emissions was at the centre of discussion. This article quantitatively assesses how much more GHGs Japan can emit by 2100 to achieve the 2 °C target in light of different effort-sharing approaches, and how Japans GHG emissions can be managed up to 2100. The long-term implications of recent energy policy developments following the Fukushima nuclear disaster for the calculated carbon budgets are also discussed.

Additionality reconsidered: lax criteria may not benefit developing countries

Abstract International negotiation on the additionality issue of the CDM (Clean Development Mechanism) seems to be proceeding without sufficient information or understanding. Especially apparent is a lack of recognition that the non-additional CERs (certified emission reductions) generated by relaxing the additionality criteria may lead to economic losses for developing countries. This article quantitatively reconfirms the effects of non-additional CERs on the international community, while clarifying that the generation of non-additional CERs in excess of a certain number will eventually lead to negative consequences for developing countries, even if these countries were able to acquire all the non-additional CERs. Furthermore, the Discussion section demonstrates that future system design would significantly affect the benefits of developing countries as well as the overall environmental integrity of the Kyoto mechanisms.

INDC Costs and Experiences in Removing Low-Carbon Technology Barriers: Japan

Japan’s INDC toward post-2020 greenhouse gas (GHG) emission reductions is at the level of a reduction of 26% by fiscal year (FY) 2030 compared to FY2013 (18% reduction compared to FY1990). After the accident of the Fukushima Daiichi nuclear power station in 2011, the GHG emission in Japan soared due to the increase of the power generation by the fossil fuel-powered station. However, in 2014, GHG emission declined due to the decrease of electricity consumption and improvement of the CO2 intensity and power generation. Current governmental energy/climate policy, which becomes the basis of the INDC, requires the industry sector to implement less energy conservation and GHG emission reduction measures compared to other sectors such as commercial, transport and household, which may result in the introduction of the specific policy such as carbon pricing to those sectors. Prioritization of nuclear power and coal-fired power as base-load power-generation technologies is also the characteristics of the current governmental policy. Since the framework to control the coal-fired power plants is voluntary in nature and the future of the nuclear power is uncertain, there is a possibility that Japan cannot achieve the INDC targets. In that case, Japan will rely on the international credits such as from the Joint Crediting Mechanism (JCM).