Australia's greenhouse gases rose for a third consecutive year in 2017, led by emissions from the gas and transport sectors, according to federal government data.
Environmental groups, however, say the true emissions figure may be under – estimated because large-scale land clearing – particularly in Queensland and lately in NSW – is not being accurately represented.
The National Greenhouse Gas inventory for last year, released without fanfare at the end of last week, showed emissions were up 1.5 per cent compared with 2016 to 533.7 million tonnes of carbon dioxide-equivalent.
After sinking during each year of the Labor-Gillard governments, emissions began to pick up with the end of the carbon price by the Abbott government in 2014.
Most economic sectors reported a rise in pollution in 2017, with so-called fugitive emissions – mostly from the liquefied gas industry – alone increasing 10.5 per cent, and transport 3.8 per cent.
The electricity industry was one sector to report an emissions reduction, cutting almost 6 million tonnes or 3.1 per cent. Hazelwood, Australia's most emissions-intensive coal-fired power plant closed last March.
Australia's emissions are "clearly going in the opposite direction" from what is needed to meet the Abbott-Turnbull government's Paris climate pledge, said Bill Hare, director of Climate Analytics. "To get to 2030 … you need to be reducing emissions about 1.5 per cent a year."
One challenge is government efforts are being curtailed. Outlays for climate action are due to shrink from $3 billion in 2017-18 to $1.25 billion by 2021-22, according the 2018 budget released last week.
Questions, too, remain about the treatment of emissions from land use changes and forestry, a sector that continues to be counted at the federal level as a carbon sink.
Last year, this category was reported as absorbing a net 22.7 million tonnes of CO2-equivalent, little changed from a year earlier.
That outcome, though, came despite as much as a five – fold increase in land-clearing in Queensland after Liberal Nationals' premier Campbell Newman loosened restrictions on native vegetation removal in late 2013.
In the most recent Queensland figures for 2015-16, the biggest land-clearing state was bulldozing at the rate of some 10-square-kilometres a day.
The 395,000 hectares cleared that year contributed 45 million tonnes of emissions, the Palaszczuk Labor government said last October.
The result is a "glaring inconsistency" between federal and state land-use emissions figures, said Martin Taylor, a conservation scientist with WWF-Australia. "It puts a question mark over [carbon accounting] that we shouldn't have."
One issue is how to count forest change. The federal government uses grid analysis that doesn't treat land as being cleared if the forest canopy remains above 20 per cent, according to Glenn Walker, a campaigner for The Wilderness Society.
By contrast, the Queensland's Statewide Landcover and Trees Study (SLATS) is more thoroughly ground-proofed with a team of eight staff, and likely more accurate, he said.
Fairfax Media sought comment from Josh Frydenberg, the environment and energy minister.
"Each year, we update land clearing estimates based on latest satellite data," a spokesperson for the federal environment department told Fairfax Media last October. "Where applicable, we also revise estimates to reflect improvements in remote sensing and estimation methods."
Mark Butler, Labor's climate spokesman said the governments land use emissions data "have for some time included seemingly inexplicable reductions in land sector emissions, and this is repeated in this last data release".
"It is crucially important that people have faith in government emission accounts, but the more I talk to the experts, the more questions are raised about the accuracy of the governments land clearing data."
Adam Bandt, the Greens climate change spokesman, said the party would use Senate estimates "to find out why these unexpected figures are now cropping up in land use and forestry".
"The government appears to now be counting pollution in the land clearing and forestry sector differently, in ways that make it appear as if theyre cutting emissions," he said.
National emissions in the last quarter of 2017 accelerated 0.8 per cent to 133.7 million tonnes – or about 2.5 per cent more than the equivalent quarter in 2013, just as the Abbott government came to power, according to the Australian Conservation Foundation.
Since the Coalition repealed the carbon prices at the end of June 2014, emissions have increased 3.6 per cent, reversing a fall of more than 11 per cent during the Rudd-Gillard Labor governments, ACF said.
The trajectory of rising emissions makes the 2030 target – of 435-441 million tonnes by that year – more difficult to reach, Gavan McFadzean, ACF's climate change program manager, said.
"We need a comprehensive national climate change plan that will rapidly cut pollution across our society and ensures Australia plays its fair role in halting global warming and ensuring we maintain our safe climate," he said.
Peter Hannam is Environment Editor at The Sydney Morning Herald. He covers broad environmental issues ranging from climate change to renewable energy for Fairfax Media.
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