Nuclear Down, Carbon Intensity Up in Japan

Japan's nuclear power fleet has sat idle since a powerful earthquake struck the nation in March 2011, driving a sharp increase in fossil fuel imports and a spike in the nation's carbon intensity, new data shows. Together, these changes have battered Japan's trade balance, increased the carbon intensity of its energy supply, and raised important questions about its future CO2 emissions trajectory.

Japan's 2011 earthquake, tsunami, and nuclear disaster have exerted substantial impacts on the nation's economy and energy system. Given Japan's reliance on nuclear power, its lack of domestic fossil resources, the magnitude of the earthquake and tsunami, and the technical and political implications of a major nuclear crisis, these impacts were largely predictable.

But although it was clear early on that Japan's triple disaster signalled major economic and technical changes in Japan, only recently has good data become available to shed light on the specifics of the changes underway.*

Two notable trends emerge from this data, both relating to Japanese energy supply. Together, these trends are exerting profound impacts on Japan's trade balance, the carbon intensity of its energy supply, and its future CO2 emission trajectory.

Carbon Intensity Spikes as Nuclear Plants Idle

First, the carbon intensity of Japan's energy mix has spiked following the shut-down of most of the nation's nuclear power fleet, which previously provided about 30 percent of the nation's electricity and anchored the nation's low-carbon energy plans. Currently, just 4 of the nation's 50 remaining nuclear reactors are online. To replace this lost generation, Japanese utilities have ramped up imports and use of coal, oil, and natural gas, while industrial consumers have been more reliant on diesel generators to guarantee reliable energy supply.

Imports of liquefied natural gas (LNG) by Japan's 10 regional utilities have increased 39 percent in January, relative to the year prior, while imports of fuel oil and crude oil both nearly tripled, according to Bloomberg. TEPCO, Japan's largest electric utility and owner of the stricken Fukushima Daiichi nuclear complex, forecasted year-on-year rises in oil, gas, and coal imports to the tune of 77 percent, 16.1 percent, and 5.3 percent respectively between the 2010-2011 and 2011-2012 periods, Reuters reported in December. And according to one analysis, between 2010 and 2011 Japan's total fossil energy imports rose 25.2 percent on a volumetrically basis.

As a result of increasing reliance on fossil fuels, the carbon intensity of Japan's energy supply, or the amount of CO2 (measured in metric tons) emitted per unit of energy supplied (measured in metric tons of oil equivalent, or TOE), has risen 15 percent year-on-year, from 2.01 metric tons CO2 per TOE in November 2010 to 2.31 in November 2011, the most recent month for which data is available. Similarly, a comparison between the 8-month period after the earthquake (April to November 2011) with the same period one year earlier reveals an increase in average carbon intensity of 7.6 percent, from 2.07 metric tons CO2 per TOW to 2.22.

CO2 Emissions Rise Even as Energy Use Falls Sharply

Second, Japan's total primary energy supply has also declined precipitously since the earthquake. Total energy supply in November 2011 was 9.8 percent lower than in November 2010, and total supply over the period April to November 2011 was down 6.7 percent on the same period in 2010**. This decrease in energy supply and use is largely driven by four factors: physical damage caused by the quake to the nation's electricity system and other energy supply infrastructure (e.g. fuel refineries etc.); the decision to idle Japan's undamaged nuclear reactors; fairly extensive damage to Japanese industry caused by the earthquake and tsunami, which reduced industrial activity and economic output; and conservation efforts launched by the Japanese government to relieve stress on the damaged electricity system, particularly in the months of peak summer demand following the quake.

Despite the steep drop in energy consumption, Japan's heightened dependence on fossil fuels and sharply increase carbon intensity drove Japan's CO2 emissions up 3.8 percent in November 2011 relative to the same month the year-prior. Average CO2 emissions over the 8-month period April to November 2011 were up 0.4 percent on the same period in 2010, even as average energy use during this period was far lower.

The following graph illustrates this dynamic, showing the drop-off in total energy supply after March 2011 in red, and rising total CO2 emissions in blue.

With Rising Fuel Imports, Japan Records First Trade Deficit in Decades

Japan's shifting energy mix has also clobbered the nation's treasured trade balance. Last week, Japanese authorities announced that after a 25 percent rise in fossil fuel imports combined with still slack industrial output has driven the country to a trade deficit of $32 billion, the nation's first since 1980. According to one analyst at Morgan Stanley, "the trade balance looks very likely to remain in deficit for the time being".

Japan's new trade deficit marks a stark contrast with business as usual for the nation, which has maintained an average trade surplus of over $100 billion for the past 10 years.

Future of Japan's Climate Targets in Question

What does this all mean for Japan's future carbon emissions and its ability to meet its targets under the Kyoto protocol? Already, the nation's leaders have conceded that they hold no hope of meeting their near-term targets. Additionally, they have refusedto sign onto any new binding emissions reductions.

Most simply, the future of Japan's emissions trajectory rides on the Japanese government's decisions on how to reconstruct the nation's energy system as the economy recovers from the earthquake and its aftermath. The most rapid and feasible path to counteract Japan's sharp rise in carbon intensity would be for the Japanese government to commit to re-operationalizing those plants within the nation's existing nuclear fleet that can successfully pass ongoing, internationally-supervised stress tests.

If the government keeps the nation's nuclear fleet offline, for reasons of public opinion or otherwise, this lost zero-carbon generation will almost certainly continue to be replaced largely by a combination of coal, oil, and LNG. Japan's renewable energy sectors are currently very small, with sources like wind, solar, and geothermal collectively providing less than 3 percent of the nation's electricity supply. While Japan has every intention to scale up the contribution of its renewable energy sectors, even the best-case scenarios envision significant time before renewable electricity can fill the low-carbon void left by Japan's current nuclear fleet.

Furthermore, prior to the earthquake and nuclear crisis, Japan's longer-term low-carbon energy transition had centered around the planned expansion of nuclear power to provide roughly 50 percent of the nation's electricity supply by 2030. Replacing the zero-carbon electricity Japan had previously planned to derive from nuclear with electricity from renewable energy sources would require a nearly 49-fold increase in the electricity provided by wind, solar, and geothermal to the national energy system, according to Breakthrough Institute analysis.

A sharp turn away from nuclear thus calls into question both Japan's near-term and long-term climate mitigation efforts.
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Mark Caine is Research Officer at the London School of Economics, Co-ordinator for the Hartwell Group, and a 2010 Breakthrough Generation Fellow. Jesse Jenkins is Director of Energy and Climate Policy at the Breakthrough Institute

*Data provided to Mark Caine by the Energy Data Modelling Centre, Institute for Energy Economics, Japan. Download the dataset and analysis as an XLS file here.

**The earthquake occurred on March 11th, 2011. Data is available until December 2011.

Front page image credit: Khalid Albaih, reproduced with permission (creative commons).