Changes for Australia’s top GHG emitters in 2022-23

The list of Australia's largest emitters of greenhouse gas (GHG) emissions changed for the 2022-23 fiscal year to 30 June, with Australian independent Woodside Energy and UK-Australian mining firm Rio Tinto each climbing one spot and Czech investment firm Sev.en Global Investments entering the rankings for the first time.

Australia's Clean Energy Regulator (CER) data show no change in the six top emitters, led by far by utility AGL Energy with 34.8mn t of carbon dioxide equivalent (CO2e). It was followed by utilities Stanwell, EnergyAustralia and Origin Energy respectively with 18.3mn t CO2e, 17.4mn t CO2e and 13.7mn t CO2e, as well as Chevron Australia at 12mn t CO2e and utility Pioneer Sail Holdings (Alinta Energy) with 10.9mn t CO2e.

Woodside surpassed Queensland state-controlled utility CS Energy to become the seventh-largest emitter in 2022-23 fiscal year, while Rio Tinto climbed one place to ninth as Genuity, formerly known as Ozgen Holdings that is part of InterGen, moved down to 15th. Sev.en entered the list for the first time as the tenth largest emitter, following its acquisition of Australia-based power operator Delta Electricity at the end of 2022 (see table).

Woodside this week said its emissions rose in calendar year 2023 because of its merger with BHP's petroleum business, noting it has secured more than 90pc of its expected requirements of Australian Carbon Credit Units to 2030.

The CER calculates Australia's biggest emitters using scope 1 emissions — those occurring directly from business activity — reported under the National Greenhouse and Energy Reporting (NGER) Act, which is used to measure and report GHG emissions and energy production and consumption.

Total scope 1 emissions reported by more than 400 companies under the scheme reached around 307mn t CO2e in 2022-23, down for the fourth year in a row and by almost 1pc from 2021-22. The electricity generation sector was mainly responsible for the overall reduction, as scope 1 emissions in the segment fell by 2.9pc from a year earlier or 4.1mn t CO2e, more than offsetting a combined increase of 3.9mn t CO2e in transport and coal mining. Increasing renewable generation has been displacing coal- and gas-fired power output in Australia, reducing emissions in the sector.

Emissions in the oil and gas sector also dropped by 3.7pc or 1.7mn t CO2e, mostly because of lower natural gas, LNG and LPG production.

Scope 2 emissions — indirect emissions from the generation of purchased energy — are also reported under the NGER. The companies with the largest reported scope 2 emissions include mining firms Rio Tinto, Alcoa, Glencore and BHP, along with Australian supermarkets Woolworths and Coles.

Rio Tinto signed two major power purchase agreements so far this year for the supply of renewable electricity to its energy-intensive Gladstone aluminium operations in Queensland state.

Australian utilities have long been among the country's largest GHG emitters because of a historical reliance on coal-fired generation, even though coal output has been falling steadily since 2018, with large emitters such as AGL transitioning to more renewable assets.

By Juan Weik