Origin Energy has pledged to reduce its carbon emissions by 50 per cent by 2032, as part of a broader transition to a low-carbon business to help limit global warming to the 2degC set at the Paris climate agreement.
The energy producer and retailer says it will halve emissions, compared to 2017 levels, from its generating-related activities.
It will also ensure a 25 per cent reduction in Scope 3 emissions - related to third-party gas and electricity purchases - over that period.
The plan will include growing renewables in its portfolio, and increasing reliance on gas, chief executive Frank Calabria says.
But the company has maintained its previous target of closing the Eraring coal-fired power plant in the early-2030s.
"We firmly believe decarbonising our business is not only the right thing to do by our stakeholders and the planet, it also presents opportunities to create value," Mr Calabria said.
Origin previously has targeted increasing renewables capacity to more than 25 per cent of its generation mix by 2020, from the current level of around 10 per cent.
It has also committed to exiting coal-fired power generation by the early 2030s, and reiterated that on Thursday.
In November, the company said it was lifting generation from the Eraring power plant in the short-term to take advantage of higher electricity prices.
The 2,880 megawatts Eraring is Australia's largest coal-fired power station and Origin's only such facility.
The company released its first report on climate change in October and, at that time, promised to announce a science-based target for emissions reduction across its business before the end of 2017.
Origin on Thursday said it will be the first Australian company to have science-based targets recognised by the global We Mean Business (WMB) initiative.
The company has backed the federal government's new national energy guarantee policy, under which energy companies will need to guarantee both supply and emissions reduction targets in a subsidy-free market.
Environmental finance group Market Forces called Origin's announcement a "greenwash" saying the company plans to do no more than close Eraring on its 50-year use-by date.
"Origin is effectively saying it will increase emissions by 57 per cent across the rest of its portfolio to 2032, before closing Eraring at a point when it will likely be too costly to run anyway," Market Forces analyst Daniel Gocher said.
"This is not leadership, this is an attempt to claim credit for business as usual."
At 1050 AEDT, Origin Energy shares were up 0.5 per cent at $9.31 in a firm Australian market.
