May we discuss 'net zero' 2050?

Environmental corrections swim against continuing environmental degradations. We see this tension, in Australia's five-yearly State of the Environment (SoE) reports.

By 2050, the official program calls for an Australian population north of 35 million. There's no end in sight, to our permissive legal framework, for land clearing and habitat removal. Mega fires have scarcely paused Victorian and NSW logging.

Second problem, while measurement of anthropogenic emissions is imperfect, it beats measurement of the earth's feedback loops. Crucial landscapes might reabsorb much less GHG than we expect. Other landscapes might do better than expected. If we weren't trashing them.

Land-related carbon capture is apples. Fossil-fuel based emissions are oranges. The apples are continually recalculated, highly approximate and less permanent.

It's a stretch to put them into the same mitigation equation as the oranges. That tempts us to defer present day "emissions reductions" in favour of "negative emissions" promised land.

Nevertheless, Garnaut's 2008 climate review estimated our rangelands and forests could be cultivated to reabsorb over 500 Mt emissions a year. His claims run much higher now. We'd have a "surplus" of carbon "credits" to sell worldwide.

Overall, his Net Zero seems a bridge too far. More likely, energy transition could be part of an industrial transition, away from our houses and holes economy.

Instead of unfurling the Net Zero banner, I'd rather we underpromise and overdeliver.

After all, this nation has Olympic medals for emissions fudges. It sat in the naughty corner at the Madrid climate talkfest.

Back at Kyoto 1997, Australia negotiated an emissions "reduction" task, that was actually an increase of 8 per cent. We finessed an "Australia Clause". Which allowed us (in particular) substantial emissions "credits" via a reduction in land clearing.

Now we're a global deforestation hotspot. Still our 2030 emissions reduction of "26-28 per cent" leans on discredited Kyoto "credits".

Rather than spurring action, the 2050 pledge might kick the can further down the road. And not even a clean emissions sheet, I argue, meaningfully "saves our environment". Especially if you're among its hundreds of fire-threatened species.