HOW WE RANK

New Zealand’s greenhouse emissions are among the highest per capita in the world using the GWP100 metric. Oxford University’s Our World In Data ranks New Zealand’s emissions as seventh highest in the OECD, with Australia, Canada and the US making up the top three.

Our methane emissions meanwhile are by far the highest per capita in the OECD — six times the average in the European Union and more than a third higher than Australia, which has the second highest methane emissions.

Our carbon emissions however are middle of the pack, just above the European Union average. Australia takes the title for the highest per capita carbon emissions, which are more than double New Zealand’s.

Globally, CO2 is the dominant greenhouse gas, accounting for 76 per cent of global emissions, with methane contributing 16 per cent and nitrous oxide 6 per cent. However, methane is responsible for about 30 percent of the warming caused by humans since the mid-1800s. Methane levels are estimated to be two-and-a-half times greater than pre-industrial levels.

Around 40 percent of the world’s anthropogenic methane emissions come from agriculture (mainly livestock, but also rice paddies), while 30 per cent is from fossil fuels, including natural gas leaks, 20 percent from landfill and waste management, and 10 per cent from burning organic matter.

In New Zealand, 88.6 percent of our methane comes from livestock, while 8.7 percent comes from waste (mostly landfills), with the remainder from the coal and gas industry.

While methane emissions from landfills have declined by 18.5 per cent since 1990, livestock emissions have remained roughly flat for the last 20 years after increasing in the 1990s. In 2020, agricultural methane emissions were 8.4 per cent higher than in 1990, but 2.6 per cent lower than the peak in 2006. In general, emissions from sheep and beef have declined, while dairy emissions have increased due to an increase in stock numbers.