Japan's greenhouse gas emissions fell 3.9 per cent to a record low in the year ended March 2019, government figures showed on Tuesday, thanks to wider use of renewable energy, the gradual return of nuclear power and lower energy demand due to warmer winter.

The annual drop was the fifth straight and contrasts with a surge in global greenhouse emissions to a record last year.

Emissions in financial year 2018/19 dropped to 1.240 billion metric tonnes of CO2 equivalent from 1.291 billion tonnes the previous year, to hit their lowest since 1990/91, when Japan began compiling data on greenhouse gas emissions, revised data from the environment ministry shows.

Japan, the world's fifth-biggest carbon emitter, has set a goal to trim emissions by 26 per cent from 2013 levels to 1.042 billion tonnes by 2030. The latest figure represents a reduction of 12.0 per cent from the 2013/14 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 2013/14.

Nine reactors have been restarted, the most since the Fukushima disaster caused the shutdown of the sector, although three of the nine are temporarily shut now for maintenance including to upgrades required under stricter anti-terrorism rules.

Renewable energy accounted for 17 per cent of electric power generation of 1.051 trillion kilowatt hour (kWh) in the 2018 financial year, up 1 percentage point on the year.

Nuclear energy came in at 6 per cent, doubling from a year earlier, while thermal power made up 77 per cent, down 4 percentage points, industry ministry data showed.