Waikato was the biggest producer of greenhouse gases in the country in 2018, new data from Statistics New Zealand shows.
For the first time, it has published emissions by regions, comparing climate pollution to population and GPD between 2007 and 2008.
While Auckland and Wellington generated the most wealth and least emissions per resident, Canterbury experienced the largest increase in greenhouse gases over that period.
Approximately two-thirds of the country's 14 regions recorded decreases in their total greenhouse gas emissions, while one-third of regions saw increases.
Overall, this resulted in a reduction of just over 1 percent in New Zealand's total greenhouse gas emissions between 2007 and 2018, environmental-economic accounts manager Stephen Oakley said.
Over that period, the largest falls in emissions were in Auckland, down 955 kilotonnes (7.8 percent), Taranaki, down 707 kilotonnes (11.3 percent), Northland, down 545 kilotonnes (10.8 percent), and Waikato, down 272 kilotonnes (2.0 percent).
Emissions increased in Canterbury, up 1175 kilotonnes (11.0 percent), Bay of Plenty, up 356 kilotonnes (11.9 percent), Southland, up 335 kilotonnes (6.2 percent), and Otago, up 333 kilotonnes (7.0 percent).
Waikato, Canterbury, and Auckland produced nearly half of the country's emissions, but some experts questioned the way this was counted.
"Care is needed when interpreting the data since the methodology used do not relate to the direct consumption of products and services in each region," Massey University professor emeritus of sustainable energy and climate mitigation, Ralph Sims said.
"Thus emissions from, say, a gas-fired power station in Taranaki are assessed for that region, and not for the regions where that electricity is consumed."
"For example, Waikato had the highest share of total emissions in 2018 (17.5 percent) due to both having the highest number of cattle (around 2 million) but also the Huntley coal-fired power station and some geothermal power plants (that also emit carbon dioxide) are located there. Over the 11-year period total emissions declined around 2 percent."