Japan’s greenhouse gas emissions declined for a fourth year as the nation boosted its use of nuclear and cleaner energy, according to preliminary figures from the Ministry of the Environment.

Emissions fell by 1 percent to 1.294 billion tons during the year ending March 31 from the previous year, according to a statement on Nov. 30.

The decline was due to an expansion of solar and wind energy, as well as restarts of nuclear reactors that had been suspended after...