The Diet on Wednesday enacted an amendment to an environment bill to allow projects aimed at confining factory-emitted carbon dioxide in undersea aquifers.
The move is part of measures to deal with global warming in line with a revised international treaty.
In November, the Convention on the Prevention of Maritime Pollution by Dumping of Wastes and other Matter, or the London Convention, was amended to conditionally authorize storing carbon dioxide in undersea aquifers.
Under Japan's revised Law Relating to the Prevention of Maritime Pollution and Maritime Disaster, the environment minister will permit such projects on condition that environment assessment surveys are conducted and continuous monitoring programs maintained.
Permission will be subject to renewal every five years to assure implementation of the monitoring programs.
The necessary technology is still in the developmental stage in Japan.