New Zealand's coronavirus lockdown triggered a massive 41 percent drop in carbon dioxide (CO2) levels, new research has found - a reduction only bettered by one country in the world.
The study - published in scientific journal Nature Climate Change on Thursday (NZ time) - was investigating temporary falls in CO2 emissions during COVID-19 lockdowns throughout the world.
It compared the CO2 levels of 69 countries, 50 US states and 30 Chinese provinces, finding that New Zealand had experienced the most significant drop of all, barring the tiny European nation of Luxembourg.
These countries and regions account for 85 percent of the world's population and 97 percent of total CO2 emissions, researchers said.
The study found that at its most extreme, New Zealand's CO2 emissions were 41.1 percent lower during lockdown than at the same point last year, while Luxembourg's fell by 44.6 percent.
Colombia (36.5 percent), Lithuania (35.3 percent), Nigeria (34.2 percent) and France (34 percent) also saw emission drops well above the world average of 26 percent.
Turkmenistan (4.5 percent), Kazakhstan (10.3 percent), Ukraine (12.4 percent) and Estonia (12.5 percent) recorded some of the world's smallest changes in CO2 levels, the research found.
The statistics for New Zealand confirms NIWA research released earlier this week, which found that air pollution was down by 75 percent in Auckland, Wellington, and Christchurch across the lockdown period.
Speaking to Newshub, air quality scientist Ian Longley said the results were "unprecedented" and would make a major difference for public health.
"What the lockdown experience has shown is as soon as we stopped driving around - which was pretty much instantly at the beginning of level 4 - the air quality responded instantly," he said.
"Basically we're looking at gases which come largely from road traffic and other sources like industry and shipping as well - that's been down by about two-thirds to three-quarters pretty much everywhere it's being measured."
Longley says the research shows that major changes can be made with collective effort.