Climate target a PR fail, minister told
New Zealand’s Paris Agreement target is inconsistent with the Government’s goal of keeping the average temperature increase to within 1.5 degrees Celsius, officials have told ministers.
The advice from the Ministry for the Environment was given to Climate Change Minister James Shaw in February and obtained by Stuff under the Official Information Act.
Shaw was told the target allows some 85 million tonnes more emissions between 2021 and 2030 than would be compatible with a 1.5C goal – putting the country over budget by about one year’s current emissions.
The Government set a goal of limiting heating to 1.5C in the Zero Carbon Act following the release of an influential report from the Intergovernmental Panel on Climate Change (IPCC).
The report concluded that letting temperatures go higher would expose hundreds of millions of people to worsening risks, including crop disruption, water scarcity and coastal flooding.
New Zealand’s Paris pledge was set by the Key Government before the IPCC report, when analysts anticipated a target of 2C.
While in Opposition, Green Party co-leader James Shaw attacked the target as being weak.
As climate change minister in the Ardern Government, he sought advice on whether the target was sufficient. Ministry analysts told him it was compatible with 2C, but not 1.5C. The advice was based on IPCC trajectories showing how fast countries’ emissions must fall to stay inside the limit.
Soon afterwards, Shaw punted the same question to the Climate Change Commission.
Two questions
In April, Shaw announced that he’d asked the commission two things: whether New Zealand’s Paris target was compatible with keeping inside 1.5C, and whether methane should be given its own separate category, to align with the Zero Carbon Act.
He did not seek Cabinet approval to update the target.
Shaw told Stuff the advice from officials ‘‘did prompt me sending the question to the Climate Change Commission, although I was heading in that direction anyway’’.
Asked why he didn’t try to raise the target based on the ministry’s advice, he said it would have taken just as long and more detail was needed.
‘‘The reason I didn’t change it on the spot is because the question is: What do you change it to?’’
The Nationally Determined Contribution (NDC), or Paris Agreement target, was developed during 18 months of consultation, including economic analysis, he said.
‘‘I actually couldn’t just change it without going through a similar process, and the whole point of the Climate Change Commission is to provide independent and expert advice,’’ Shaw said.
‘‘I thought it would be undermining of the commission, which had only just been established, to go another way.’’
The Climate Change Commission’s creation had been delayed by political negotiations to get bipartisan support for the Zero Carbon Act.
The Covid-19 pandemic has further delayed its work.
It will report back on the Paris target in May, after which the Government will make a decision about whether to change the pledge. The commission will also recommend a series of emissions budgets.
CO2 challenge
While their advice was that New Zealand’s pledge fell short, the analysts suggested a seemingly painless way to be compliant with a 1.5C goal: splitting the target into separate reductions for methane and carbon dioxide.
The Zero Carbon Act splits the gases, but the Paris target doesn’t.
‘‘When considered via a split gas approach, our NDC is likely to be consistent with 1.5C,’’ the advice reads.
New Zealand’s current promise to other nations under the Paris Agreement is to cut emissions by 30 per cent from 2005 levels by 2030.
The pledge is expressed as a budget for the whole decade’s emissions, and all gases are encompassed by a single target, with methane and nitrous oxide converted into carbon-dioxide equivalents.
The budget requires keeping emissions to 600 million tonnes of carbon dioxide equivalent for the whole decade from 2021 to 2030.
In round numbers, that gives us an average allowance of 60 million tonnes a year.
Since New Zealand currently produces over 70 tonnes a year (in net terms), yearly emissions will need to be well under 60 million tonnes by 2030 to meet the target.
In all, the budget requires shaving off close to 100 million tonnes off over the decade – more than a year’s worth of emissions.
But to be in line with the IPCC trajectories for a 1.5C maximum, we’d need to slough off another 85 million tonnes, capping emissions at more like 516 million tonnes for the decade – almost double the reduction currently planned, Shaw was told.
Lumping is losing
The analysts added that New Zealand would look much better in the eyes of observers – and could be consistent with 1.5C – if we stopped lumping in methane with carbon dioxide.
The gist of their argument was that because our Paris pledge mingles all gases together, our softer domestic policy targets for methane make the comparatively steep carbon targets look weak.
New Zealand’s Paris pledge converts every tonne of methane into an equivalent of carbon dioxide, based on its heating effect over 100 years. That approach is in line with the accepted international practice, and it’s how New Zealand reports its annual emissions to the United Nations.
But converting methane to carbon dioxide equivalents can distort the true impact, as the officials noted.
In reality, making cuts to methane now would cool the climate by 2030. Much of the existing methane would break down within the decade, lowering the thermostat. Yet when that methane is expressed in carbon dioxide equivalents, it appears on paper as if cutting methane would let the mercury keep rising – because that’s what would happen if the gas in question was truly carbon dioxide.
This difference, along with pressure on behalf of farmers, is why the Government imposed a light interim cut for methane in the Zero Carbon Act, of 10 per cent from 2017 levels by 2030.
For the first five years of this decade, there will be no methane cuts at all, because agricultural limits don’t begin until 2025.
There’s scientific support for treating methane more lightly. While researchers debate what level of ongoing methane emissions is defensible, they are united in saying methane needn’t get to zero, unlike carbon.
But with deeper cuts to methane off the table, the bulk of the cuts that are needed to stay inside the Paris budget must come from shrinking carbon dioxide and nitrous oxide which, like methane, is mostly produced by farming.
‘‘As a result of the comparatively low level of reduction in biogenic methane emissions, emissions of all other gases will need to reduce significantly more in order to meet the NDC target,’’ the officials wrote to Shaw.
The analysts estimated how much carbon would need to fall.
Of the 600 million-tonne allowance for the decade, methane will take up about 311 million tonnes, even with the 10 per cent reduction.
That leaves 290 million tonnes for carbon dioxide and nitrous oxide to share, they calculated.
By the analysts’ estimate, longlived gases will need to reduce by 43 per cent below 2017 levels by 2030, even after incorporating forestry removals – though the advice notes that estimate is ‘‘highly sensitive to updates’’.
Given New Zealand has very little coal-fired electricity generation to cull, ‘‘our assessment is that New Zealand’s NDC is already highly ambitious,’’ the analysts said.
In essence, they suggested the packaging of the targets was a public relations fail.
The memorandums complain that non-government organisations and the likes of Climate Action Tracker often ‘‘misunderstand’’ New Zealand’s NDC because they only compare headline numbers, noting New Zealand’s media ‘‘often’’ repeats these harsh assessments.
‘‘An all-gases approach does not adequately reflect the contribution in our NDC and can lead to invalid assessment of our contribution,’’ the advice reads.
The Paris Agreement gives countries enough flexibility to use a split gas target if they wish.
Whether New Zealand should do that – and what the next decade’s emissions budgets should be – is now a question for the Climate Change Commission.