The Climate Change Commission today unveiled its final advice to the Government on how and where to slash New Zealand's greenhouse gas emissions. Why is that a big deal for the rest of us? Science reporter Jamie Morton explains.
The simple answer is it doesn't just represent our clearest pathway yet to getting our emissions under control, so that New Zealand is doing its bit toward the global effort to spare the world the worst impacts of climate change.
It spells a wholesale transformation across virtually every corner of the economy – from the cars we drive and import, and the cows and sheep we farm, through to the energy we produce and consume, the forests we plant and the houses we build.
Moreover, it sets out a radical transition that, while changing the face of our country forever, would largely all happen within the next 15 years.
This time, it's not just another report full of big ideas that ministers can discuss briefly and then ignore.
To briefly recap: soon after the independent commission was born from New Zealand's Zero Carbon Act, it was given its first task – looking at whether the commitments we'd locked in fitted with the world's aspiration to limit global warming to 1.5C.
Its draft advice, released in January, unsurprisingly found they didn't.
It found we were on track to undershoot our set 2050 target of net-zero long-lived gases by some 6.3 million tonnes of carbon dioxide equivalent – and that we couldn't keep planting our way out of tough action.
New Zealand could get where it needed to without having to wait for emissions-busting technology – but it'd mean making some major changes.
A central part of the commission's advice was also to recommend New Zealand's first three five-year emissions budgets, taking us out to 2035.
Such was the scale of the transformative shifts discussed in that first report that it bore huge and immediate implications for every sector – and drew around 15,000 submissions.
Provided the Government adopted the budgets and acted on them, by 2035, New Zealand would have slashed its carbon emissions by 63 per cent, and biogenic methane by 17 per cent.
That would put us on track to meet our target of net zero emissions of long-lived greenhouse gases by 2050 – and also bring down biogenic methane emissions by between 24 and 47 per cent.
The budgets set out cuts of all net greenhouse gas emissions by 12 per cent, 27 per cent and 42 per cent below 2019 levels by 2025, 2030 and 2035 respectively.
The commission again set out the large-scale changes that would need to happen over that 15-year period - and most of the headline shifts hadn't changed from its last advice.
Imports of used petrol cars, for instance, would need to be wound down by 2032, and around 380,000ha of new exotic forestry would need to be planted by 2035.
Livestock numbers would require a sizeable cull this decade.
By 2035, 60 per cent of New Zealand's energy would need to come from renewable sources, and by mid-century, low and medium temperature heat in industry and buildings would come from electricity and biomass.
It found road transport – New Zealand's fastest-growing source of emissions, and making up nearly half the CO2 we send into the atmosphere today – could be "almost completely" decarbonised by 2050.
That would come through more cycling, walking and use of public transport, along with working from home and switching to low emissions vehicles.
But it'd also require a "rapid increase" in EV sales, so that all nearly all cars entering the country were electric by 2035 – or four years after the commission assumed that new EVs would hit price parity with new petrol cars.
The road for agriculture was similarly steep: and without new technologies, meeting the more ambitious end of the commission's target range would likely require more land use change and "significantly" lower agricultural production from livestock.
But perhaps the biggest take-away was the economic pain the country could save itself by going hard and early.
Going ahead with the commission's recommended budgets would see the level of GDP fall by around 0.5 per cent in 2035, and 1.2 per cent in 2050 – but not acting would mean double that hit.
The biggest change was the commission's use of a more recent emissions inventory – 2019's – which unfortunately made for a slightly steeper climb and deeper cuts.
For instance, the draft advice recommended net cuts to all greenhouse gases of two, 17 and 36 per cent over each of the next three five-year periods, compared with 2018 levels.
While much of those headline numbers for each sector hadn't shifted, the commission did reconsider many of its specific assumptions, based on more modelling and feedback from submitters.
Further analysis around supply constraints prompted the commission to walk back its projections around the uptake of used EVs this decade – although the modelled uptake of new EVs didn't change, and other carbon-cutting opportunities were found in biofuels and low-emissions aircraft.
On one hand, the commission was too conservative the first time around energy efficiency improvements in buildings – but on the other, its initial assumptions on the cost of moving away from fossil fuel-based heating were found to be too low.
The final advice assumed Methanex would exit the market in 2040, rather than 2029 as initially modelled – but it also brought forward the Tiwai Point aluminum smelter's closure.
And with agriculture, the commission acknowledged its assumptions about what could be achieved with on-farm improvements had been "overly optimistic and beyond what can be achieved".
But it still suggested sharp livestock cuts – with dairy cattle numbers falling by 13 per cent below 2019 levels by the end of this decade, and sheep and beef cattle numbers falling by around the same.
Elsewhere, the advice had been updated to reflect a stronger partnership with iwi, a focus on equity, and closer analysis of emerging technologies.
Scientists and policy experts have generally been impressed at how comprehensive the commission's masterplan is – one Niwa climate scientist called it a "breath of fresh air" - even while taking issue with some of its conclusions.
Greenpeace argued the commission could have been much tougher on methane emissions – citing a "cow-shaped hole" in the advice.
"If this Government is serious about tackling the climate crisis, it must do what we already know will cut climate pollution from intensive dairying: phase out synthetic nitrogen fertiliser, substantially reduce stocking rates, and support farmers to shift to regenerative organic farming," said the group's climate spokesperson, Amanda Larsson.
But DairyNZ contended that meeting the suggested targets would still prove a "big ask" and Federated Farmers called for more funding support - and specialists - to get farmers access to the science and technology needed to make improvements.
Forestry groups have aired worries that the commission was risking forest planting rates by stating that the current Emissions Trading Scheme would "incentivise more production forestry than needed".
The Government now has the tough task of going away and looking at which – if not all of – the recommendations it will factor into its own Emissions Reductions Plan, due by December 31.
If it decides to ignore the commission's blueprint altogether, it'll somehow have to come up with something better.
Whatever the outcome, Kiwis can expect some radical change this decade, as the need to tackle the climate crisis becomes all the more urgent.
Firefighters responded shortly before 9am on Friday.