Cabinet ministers have approved a plan to reduce greenhouse gases by 26 percent by 2030, a goal already criticized by environmental groups as too timid and statistically unsound.
The cuts, first unveiled in a draft in April, will use 2013 as a baseline. Acceptance of the draft report was announced Tuesday by Environment Minister Yoshio Mochizuki. Final approval will be sought after public comment.
Adopting 2013 as a starting point is contentious because it's a year when Japan recorded its second-highest emissions level ever as it burned more fossil fuels to replace nuclear power lost after the Fukushima crisis.
"We know there are various opinions," Mochizuki told reporters. "We will explain our target to other countries to gain their understanding."
Were Japan to use 1990 or 2005, the base years for other nations, it would leave the nation trailing the pack of richer industrial nations working to rein in the pollution blamed for global warming.
Japan aims to submit its pledges to the United Nations by the end of July, according to Hiroaki Takiguchi, a ministry official in charge of climate change.