The process of setting a new goal on reducing greenhouse gas emissions was marred by a standoff between the Ministry of Economy, Trade and Industry and the Environment Ministry.
METI, long a champion of nuclear power, was reluctant to set the target and the Environment Ministry was trying to avoid postponing another commitment.
The rivalry appeared at one point to threaten the establishment of any new target, but they eventually reached an agreement after political intervention.
With the government unable to propose a clear-cut nuclear policy for the future, the new goal lacks specifics, an ambiguity that has drawn a chorus of international criticism.
"It's an ambitious goal, one that requires the utmost effort to achieve it," Environment Minister Nobuteru Ishihara said at a news conference. The new target is a 3.8 percent "cut" in emissions by fiscal 2020 from the 2005 level.
Of the 3.8 percent, 2.8 points represent carbon dioxide absorption by forests, while reduction via such measures as expansion of renewable energy and energy-conservation, accounts for only 1 point.
The specifics meanwhile remain unclear. While numerical benchmarks are set for energy-saving on various fronts, no mention is made of the degree of reliance on renewable energy, what to do about nuclear power, as well as what action businesses or households should take in achieving the reduction.
In the background is the government's failure to initiate a rethink on energy policy, leaving emission volumes at its mercy.
After its inauguration in late 2012, Prime Minister Shinzo Abe's government restarted discussions on revising the country's long- to midterm energy plan, which serves as a guideline for energy policies and was last formulated in June 2010 under the government led by the Democratic Party of Japan.
But the Abe government has not made progress with discussions to determine how much of the country's electricity needs should be met by atomic power. All reactors remain offline for safety screening, and many voices are calling for nuclear to be abandoned in the wake of the Fukushima meltdowns.
Over the summer, the Environment Ministry explored the option of setting a flexible greenhouse gas reduction target, assuming varying rates of nuclear dependence for 2020, including zero and 10 percent.
The Environment Ministry projections factored in numerous combinations of options from renewable energy sources and energy conservation initiatives.
But METI called a halt on work to set a new emission target, fearing that giving any hint of reliance on nuclear power, even if only theoretical, would provoke communities hosting atomic power plants that have not received full safety assurances.
The divide between the two ministries deepened in working-level consultations, making it necessary to be taken up in closed-door sessions by top officials in autumn. The officials included the environment, industry and foreign ministers, as well as the chief Cabinet secretary.
It is Chief Cabinet Secretary Yoshihide Suga who is believed to have issued the call for making an announcement of the goal at the 19th session of the Conference of the Parties under the U.N. Framework Convention on Climate Change, assuming zero reliance on nuclear power.
An official of the Foreign Ministry, which is involved in international negotiations, said: "Next fall, a summit-level meeting on climate change is scheduled at the United Nations and the prime minister will participate in it. We decided it is not desirable for the prime minister to announce a goal (with a limited reduction) there, and also that it would be too late to wait until the next occasion."
The latest target — a 3.8 percent cut by fiscal 2020 from the fiscal 2005 level — actually represents an increase in emissions of 3.1 percent from the Kyoto Protocol base year of fiscal 1990, given that the protocol aimed for a cut of 6 percent from 1990 for fiscal 2008-2012.
The government says the modest goal is unavoidable because it is based on zero reliance on nuclear power, but questions remain.
In June last year, an Environment Ministry panel under the DPJ government estimated that Japan in 2020 can achieve a 3 percent reduction from fiscal 1990 without using nuclear power while assuming some economic growth.
Unlike the latest target, the goal at the time did not take into account greenhouse gas absorption by forests. The DPJ government's target would have been even higher if the forest absorption credit had been added.
The DPJ held public discussions in many parts of the country by presenting various options for reduction targets and solicited opinions from nearly 90,000 people.
Transparency does not appear to be a strong point of Abe's Liberal Democratic Party-led government, which is also pushing for legislation to guard information in the name of protecting state secrets.