Japan's new prime minister said on Monday the nation will seek to become carbon-neutral by 2050, a move that will require huge changes in its fossil fuel-heavy energy mix in order to succeed.

Why it matters: Japan is the world's fifth-largest largest source of carbon emissions. The new goal announced by Prime Minister Yoshihide Suga is stronger than the country's previous target of becoming carbon neutral as early as possible in the later half of the century.

Driving the news: “Responding to climate change is no longer a constraint on economic growth,” the prime minister told the nation's parliament Monday, per The Washington Post.

• “We need to change our thinking to the view that taking assertive measures against climate change will lead to changes in industrial structure and the economy that will bring about great growth.”

The big picture: A growing number of countries are making pledges consistent with what scientists say is needed to meet the Paris climate deal's goals for limiting the amount of temperature rise.

• Japan's pledge comes a month after China — by far the world's largest greenhouse gas emitter — vowed to be carbon neutral by 2060.
• European Union officials are working to put meat on the bones of their promise to achieve net-zero emissions by 2050.
• Joe Biden's platform calls for having the U.S., the second-largest emitter after China, achieve net-zero emissions by 2050 as well.

Yes, but: These long-term pledges will require massive policy shifts — plans that for now are often just vaguely articulated — to transform them into steep emissions cuts.

• Helen Mountford of the World Resources Institute applauded Suga's pledge, but added: "In order for Japan to demonstrate it takes this net-zero pledge seriously, the country must also set a much bolder emissions reduction target for 2030 than the surprisingly weak plan it put forward earlier this year."
• And the New York Times points out that Japan is currently still investing in coal-fired power. Per the Times, Japan has "planned or is in the process of building 17 new coal-burning power plants."

What's next, via Bloomberg:"Concrete goals to promote hydrogen, battery storage, carbon recycling and wind power will be identified in a report released by the end of the year, Minister of Economy, Trade and Industry, Hiroshi Kajiyama told reporters Monday."