Australia

Historical emissions data cover the period 1990–2024. They are taken from Australia's National Inventory Report 2022, available from Australia’s National Greenhouse Accounts (DCCEEW, 2024b), and from the March 2024 Quarterly Update of Australia’s National Greenhouse Gas Inventory, published in August 2024 (DCCEEW, 2024i).

Emissions from the Quarterly Update are converted to AR4 using the AR5/AR4 ratio from National Inventory Report 2022 (DCCEEW, 2024b).

Conclusions of the present CAT assessment are subject to uncertainty in light of Australia’s frequent revisions of its emissions data. The government has repeatedly revised emissions projections downwards. This has typically not been backed by stronger climate policies but is rather the result of a change in assumptions.

The government has set an emissions reductions target of 43% below 2005 levels including LULUCF. To recalculate this target excluding LULUCF, we determine the targeted emissions level in 2030 including LULUCF (i.e. 43% below 2005 levels), then subtract LULUCF sequestration projected by the government for 2030. We then compare this projected emissions level excluding LULUCF in 2030 to 2005 emissions excluding LULUCF. We recalculate the NDC target excluding LULUCF every time the historical and projected emissions are updated.

There have been significant recalculations of the LULUCF sector sequestration estimates for 2030, ranging from 1 MtCO₂e projected in 2018 to 57 MtCO₂e projected in 2023 (DCCEEW, 2023b). We derive LULUCF projections in this CAT update by harmonising the government’s 2023 LULUCF projections with the 2022 LULUCF data point from the latest Quarterly inventory (DCCEEW, 2023b, 2024i), which results in 2030 LULUCF sequestration of 79 MtCO₂e in 2030.

The policies and action projection are based on government projections from 2023 (DCCEEW, 2023b). The CAT always provides policies and action projections excluding LULUCF. To this end, the CAT subtracted the projections provided for LULUCF.

The current policy projections are based on the ‘baseline’ scenario of the 2023 projections, adjusted to include mitigation from the New Vehicle Efficiency Standard (NVES) as this measure has now been implemented. The NVES is part of the government’s 2023 ‘with additional measures’ scenario.

The government’s baseline scenario includes "current policies and measures and announced policies where there is sufficient detail to make robust assumptions in the modelling” (DCCEEW, 2023b). New policies introduced in the 2023 baseline scenario that were not included in the 2022 version, include: the Safeguard Mechanism reform, the Safeguard Transformation Stream, elements of the National Electric Vehicle Strategy, notably the Fringe Benefits Tax exemption, the Household Energy Upgrade Fund the original framework of the Capacity Investment Scheme (before its November 2023 modification), and the Renewable Energy Guarantee of Origin. The full list of policies integrated in this scenario is available in the 2023 projections (DCCEEW, 2023b).

The announced policy projections align with the ‘with additional measures’ scenario of the 2023 government projections, which includes policies that “have been announced but where detailed design is still under consultation” (DCCEEW, 2023b).

The ‘with additional measures’ scenario includes the 82% renewable electricity target by 2030 for the country’s grids, but not the expansion of the Capacity Investment Scheme announced in November 2023, which is not included in either government scenario (DCCEEW, 2023b).

We use the most recent available update of the Long-Term Emissions Reduction Plan as a basis for assessing Australia’s climate trajectory to 2050. The government is currently preparing an update of the 2050 Net Zero Roadmap.

To assess the net zero target, we used the scenario “The Plan”, modelled by DISER (Australian Government, 2021c). “The Plan” scenario incorporates a sequestration of 38 MtCO₂e through bioenergy with carbon capture and storage (BECCS), which is considered in our target assessment. We converted these values to AR4 Global Warming Potentials (GWPs), using the AR5/AR4 ratio from current policy projections.

The CAT uses Global Warming Potential (GWP) values from the IPCC's Fourth Assessment Report (AR4) for all its figures and time series unless stated otherwise. Assessments completed prior to December 2018 (COP24) used GWP values from the Second Assessment Report (SAR). To be relevant to national context, values using AR5 are sometimes added to the text.