Countries set their own national targets, but they are supposed to aim for maximum ambition. File photo. Photo: 123RF
A former top climate diplomat says New Zealand is going to have to step up its game the next time sets a climate target.
Kay Harrison was New Zealand's climate change ambassador from 2019 to July 2024, representing the government at global climate summits.
All countries have to submit a new target in February, saying how much they will slash emissions under the international Paris Agreement between 2031 and 2035.
The current target is 50 percent, from 2021 to 2030.
Harrison told the Climate Change and Business Conference in Auckland that the next target needed to start with a 6, "at least."
Countries set their own national targets, but they are supposed to aim for maximum ambition. Every pledge has to be more ambitious than the last, a provision known as the "ratchet" mechanism.
Harrison was a top diplomat at the Ministry of Foreign Affairs and Trade in 2021, when the government set the current target for 2021-2030.
She told the conference that some people in government were not pleased when they were told the target needed to be 50 percent.
The second phase of national commitments is in 2031-2035.
The first global stocktake took place last year, adding up all countries' promises.
It found the first phase of Paris pledges by countries had avoided the worst scenarios of global warming, but the planet was still on track for 2.9C heating, even if every country met its targets. That is a level of extreme weather and heat which climate scientists say would be devastating.
Countries are being urged to do better with their 2031-2035 pledges.
If government can't do enough inside its borders to make a respectable pledge, it is allowed to buy climate action from other countries.
That is what New Zealand has always planned to do since it set its pledge in 2015 and updated it in 2021.
Switzerland and Singapore have signed deals with Thailand and Laos, respectively.
New Zealand has not signed any deals, despite the successive governments knowing they need about 100 million tonnes of carbon savings from overseas.
Politicians from both Labour and National have previously said they would like to meet more of the target inside New Zealand, but independent watchdogs have reported New Zealand might not even meet the minimum amount of domestic action required already.
Catherine Leining of economic consultancy Motu told the conference that international cooperation was a good thing, because most of the opportunities for low cost carbon savings were in developing countries, and they could not afford to do all the work themselves.
A combination of taking action at home and funding action in poorer countries was the only way to meet global targets, she said.
Treasury has put the cost of buying 100 million tonnes from overseas at anywhere from $3-23 billion.
But Leining said if the cost came out near the top of that range it meant New Zealand was "doing it wrong".
She said the high end of prices was for top end purchases from Europe, "not the developing countries we should be helping".
A recent briefing from government officials told politicians they risked paying five times as much for these purchases if they waited until close to 2030.
Harrison said New Zealand was "late to the party" at securing what it needed on the global market.
She said the next target would likely require more overseas purchases than the current one.