Partial data for the first quarter of 2023 just released by the Ministry of Business, Innovation, and Employment, shows that emissions from oil, gas, and coal are down 3%, 26%, and 29% respectively after peaking in 2019, with the percentage of generation from renewables reaching the high 90s.

Robert McLachlan, Massey University distinguished professor in Applied Mathematics, says it’s easy to see why electricity emissions are down. “The lakes are full, new wind farms are opening, and there has been some demand reduction, for example by the closure of the Marsden Point oil refinery.

“Over the next few years, the first large solar farms will start operating, further lowering emissions from this sector.”

IMAGE: Robert McLachlan

McLachlan says that the reasons for falls in gas and coal use are harder to read. “Gas use is partly driven by the availability of supply, which has been declining, and is projected to fall precipitously over 2024-2030.

“The fall in coal use (CO2 down 700,000 tonnes a year from 2019 peaks) is quite large compared to the individual coal replacement projects. Fonterra’s largest project cut 84,000 tonnes, with a second project of 48,000 tonnes due for completion this year.”

MBIE will later release a detailed breakdown by industry, which will make this easier to interpret.

“One thing this chart shows clearly is the overwhelming importance of oil,” McLachlan says. “The 16,000 battery electric vehicles sold in 2022 cut emissions by around 40,000 tonnes of CO2, just a tiny fraction of the fall of 700,000 tonnes between 2019 and 2022, which itself is a tiny fraction of the 19 million tonnes a year coming from this sector.”

He says most of the drop is due to behaviour change – driving less (in part due to the price of petrol), and working from home.

And New Zealand is still baking in long-term dependency on oil, importing 6000 new cars and trucks every week, 80% of which are destined to burn fossil fuels for decades to come.