It is the fifth straight annual decline and comes against a surge in global greenhouse emissions to a record last year.
Emissions in financial year 2018/19 dropped to 1.244 billion metric tonnes of CO2 equivalent from 1.291 billion the previous year, to hit their lowest since financial year 1990/91, when Japan began compiling data on greenhouse gas emissions, preliminary data from the environment ministry shows.
Japan, the world’s fifth-biggest carbon emitter, has set a goal to trim emissions by 26% from 2013 levels to 1.042 billion tonnes by 2030. The latest figure represents a reduction of 11.8% from 2013 levels, data showed.
The nation’s emissions had surged after the 2011 nuclear disaster at Fukushima led to the closure of atomic power plants and boosted reliance on fossil fuels, but have turned lower since a peak of 1.41 billion tonnes hit in fiscal 2013.
Nine reactors have been restarted, the most since the Fukushima disaster caused the shutdown of the sector.
Renewable energy accounted for 16.9% of electric power generation of 1.047 trillion kilowatt hour (kWh) in the 2018 financial year, up 0.9 percentage points on the year.
Nuclear energy came in at 6.2%, doubling from 3.1% a year, while thermal power formed 76.9%, down 4 percentage points, industry ministry data showed.