TOKYO, Dec. 5 (Kyodo) — Greenhouse gases equivalent to 1,307 million tons of carbon dioxide were emitted in Japan in fiscal 2011 through March 2012, up 3.9 percent from the previous year, the Environment Ministry said Wednesday in a preliminary report.

The rise was mainly due to increased operation of thermal power plants after almost all of the country's nuclear power plants were shut down in the wake of the March 2011 earthquake and tsunami that crippled the Fukushima Daiichi nuclear complex.

Emissions in fiscal 2011 were the highest since fiscal 2008 when emission reduction requirements under the Kyoto Protocol started.

Compared with levels in 1990, the base year under the Kyoto Protocol, emissions in fiscal 2011 were up 3.6 percent.

By including emissions rights bought abroad, a 9.2 percent reduction was attained on average from fiscal 2008 to 2011.

Slower manufacturing output and households' energy-saving after the earthquake also contributed to the reduction, the ministry said.

By sector, industry emissions declined 0.2 percent from the preceding year, while household emissions rose 9.7 percent.

Under the protocol for reducing greenhouse gas emissions, Japan is obliged to cut its emissions by 6 percent from 1990 levels on average over a five-year period from 2008 to 2012.

Environment Minister Hiroyuki Nagahama told reporters in Doha that he believes the target under the protocol is attainable as reductions from fiscal 2008 to 2011 have exceeded the target.

Nagahama is in the capital of Qatar to attend the 18th United Nations Conference of the Parties to the U.N. Framework Convention on Climate Change.

But emissions are expected to stay on the uptrend with most of the country's nuclear power plants remaining offline.

"The target under the Kyoto Protocol is seen attainable thanks to emission reductions in the past, but Japan needs further energy saving and promotion of renewable energy," a ministry official said.