Climate Change Commission rejects criticism in court: We knew our 1.5C maths was 'blunt'
The Climate Change Commission has defended its right to forge its own carbon-cutting trajectory and use blunt, even controversial assessments of its proposals since its an independent expert advisory body. A group of more than 300 climate-concerned legal professionals, Lawyers for Climate Action, have challenged the commissions work in the High Court, claiming the body made several fundamental errors. These gave the false appearance that the commissions domestic carbon budgets and the countrys international carbon-cutting pledge are in line with the action required to limit global heating to 1.5 degrees Celsius, Lawyers for Climate Action argue. It wants the commission to be ordered back to the drawing board, with a lot more attention paid to a global scientific report produced by an expert climate body on the action required to achieve 1.5C. The commission rejects that it should be held hostage to the report in question. As the expert body appointed by the Government, the commission says it did its job based on the criteria of the Zero Carbon Act and was well aware of the issues raised in the hearing when it completed its work. READ MORE: * Climate Commission responds before fire closes court: We can't move as fast as activists desire * 5 + 13 = 3: Climate Commission relies on "irrational" maths to justify advice, lawyers argue * Legal action against the Climate Change Commission: Necessary, influential and helpful Short on time? Here are three key points: In the opening days of the hearing, Lawyers for Climate Action noted that a headline ambition of the Zero Carbon Act is to contribut[e] to the global effort under the Paris Agreement to limit the global average temperature increase to 1.5C. The Act also requires the commission to use a broad range of domestic and international scientific advice. The group argued a global report from climate expert body the Intergovernmental Panel on Climate Change being the most comprehensive and authoritative statement should have been a central resource in setting the countrys first three carbon budgets, as well as the NDC. The report found global net carbon dioxide emissions needed to fall between 40 and 58 per cent by 2030, compared to a net 2010 baseline. Biological methane would need to fall between 11 and 30 per cent and nitrous oxide by up to 21 per cent. Once this analysis had been completed, then the commission could apply value judgments such as the economic and social impact to adjust the domestic budgets up or down, Lawyers for Climate Action argued. Instead, the commission set its budgets first, based on domestic modelling, and then did a cursory and faulty assessment of them against the IPCCs 1.5C work, the court heard. Representing the commission, Victoria Casey QC defended its expertise and right to make the choices it did. The need to take action to achieve the 1.5C global temperature goal was built into the bones of the commissions work, Casey told the court. It is not an afterthought. But she agreed that the commission did not use the IPCCs 1.5C trajectories as a starting point, though argued there was no obligation for it to do so. Although the work must be based on science, the law doesnt specify this report. Casey said the IPCC itself noted its pathways do not represent central estimates, national strategies and do not indicate requirements. Notably, translating the global trajectory onto each country would punish the countries that had already made large carbon cuts and advantage countries that havent taken action, Casey argued. (With comparatively large emissions rises since 1990 , New Zealand is one of the latter.) Casey said the witnesses for Lawyers for Climate Action agreed that the IPCC pathways were not intended to be blindly applied to individual countries. IPCC author Joeri Rogelj noted this would be a conceptionally questionable approach, adding that some calculations conclude New Zealand should make far deeper emissions cuts compared to the pathways. Casey said that centralising one piece of scientific work would hold the commission hostage to it, and potentially curb the powers of the Climate Change Minister, who is required under the Act to set five-year domestic carbon budgets in response to the commissions advice. In addition, the Government always intended to top up its domestic cuts by paying other countries to take action, she said. These additional gains would be included in New Zealands NDC. Therefore, it was only appropriate to use the IPCCs work to inform advice on a minimum level of ambition for the NDC which the commission argues it did. The commission compared both the carbon cuts advised for New Zealand and the NDC against the IPCCs work. Lawyers for Climate Action say that when the commission did the second comparison, it used irrational maths. The IPCC compares net emissions in the baseline year in 2010 against net emissions. In its analysis, the commission compared gross emissions (which exclude emissions from forestry) against net emissions (which includes the carbon absorbed by trees). This poor-quality assessment meant the public was told the countrys proposed domestic and international action was in line with efforts to achieve 1.5C, even though in reality it would fall short, the court heard. Lawyers for Climate Action say this is such a fundamental error that the court should order the commission to re-do its work. In rejecting the claims, the commission agreed that other experts might question its maths. Matthew Smith wrote that the commission was well aware it was taking a blunt approach. We knew we were comparing an orange (the NDC) with a range of apples (the IPCC pathways) and not only because of the net and gross-net issue, Smith said. We recognised that others may disagree with our judgment calls... [but] the choices the commission made were deliberate, considered and well-informed. Because this is a judicial review, arguing a choice is controversial can be a defence: the presiding judge can only rule that a decision is unlawful, not make a call on the quality of that decision. Casey argued that if the commission was forced to use net-net comparisons to compare its advice to the IPCC pathways, then that would be unsuitable and it could simply decide not to use the IPCC work. Lawyers for Climate Action is also trying to convince Justice Jillian Mallon that the Zero Carbon Act requires the commission to use a certain type of carbon accounting, known as the Greenhouse Gas Inventory (GHGI) method. The law mentions the Inventory, which is prepared each year and submitted to the UN. In addition, one witness argued that comparisons with the IPCC paths must use GHGI accounting, otherwise the comparison would be meaningless. But the commission chose to use another type of carbon accounting, the system used to set the NDC. In defence of the claims, Casey noted that far fewer of Lawyer for Climate Actions witnesses made statements in support of Greenhouse Gas Inventory accounting. One benefit of NDC accounting is that it only counted permanent emissions reductions, as it smoothed out the dips and peaks of plantation forests, the defence argued. Counsel for the commission stressed that slow, steady cuts to domestic greenhouse emissions were the best course of action. The unprecedented change to build a net-zero country would be extremely challenging, Casey said. Putting your head down and running at the target is clearly not the way to achieve that. The defence also argued that since much of Lawyers for Climate Actions evidence had arisen after the commission released its advice, it should not be admitted. The commission will conclude its arguments Friday. As he receives the commissions advice and works with the Government to set carbon budgets and the NDC, Climate Change Minister James Shaw is also named in the suit. Counsel representing the minister is also expected to speak on Friday, the day the hearing was set to close. Interruptions including from fires lit by Parliamentary protestors on Wednesday could impact the completion of the hearing this week.