Dairy expansions and greenhouse gases surged since 1990 - report
New Zealand's small population has allowed it to get away with "atrocious" behaviour when it comes to the environment.
But a report into the state of the environment, the first of its kind since 2007, shows Kiwis are changing their attitudes and investing heavily in reducing the damage.
The issues are covered in the Environment Aotearoa 2015 report, which Waikato Professor of International Law, Alexander Gillespie said will help identify gaps in the way New Zealand tackles environmental challenges.
The report found a 28 per cent surge in the land area used for dairy farming had caused more land to be dangerously trampled down. The dairy boom has also created a spike in the amount of effluent leaching into the soil and fresh waterways.
Gillespie is known internationally for his work on environmental law and is a regular commentator on environmental policies.
He said New Zealand's small population had allowed the country to get away with behaviour that he said was "atrocious".
"We are getting better, but the way we treat our waterways is atrocious, our air pollution, our emissions ... we get away with a helluva lot because we are are a country with four million people in it."
"If we had the population of the Netherlands or Japan, the place would be a desert."
The report, jointly released by Statistics New Zealand and the Ministry for the Environment, is the first report into the state of the environment since 2007.
It revealed a damning surge in greenhouse gases, which have risen 42 per cent since 1990.
The soil beneath around 80 per cent of dairy farms had been badly damaged by compaction, making land less productive and degrading the quality of waterways.
Dairy farmers had made "measurable progress" since the last report, Dairy NZ's environment policy manager, Dr Mike Scarsbrook said.
"More than $1 billion over the past five years has been spent by farmers in effluent systems, riparian planting and retiring sensitive land. That equates to $90,000 by each dairy business throughout New Zealand," he said.
Climate scientist Jim Salinger said it was clear to see dairy conversions were taking a toll on the environment, but the solution was "a community decision to make".
"At the end of the day we have to address agriculture but if we delay dairy conversions that does have an impact on the economy.
"We need to start massively researching how to reduce our methane emissions from pastoral agriculture and then starting to apply that."
Nitrogen on land had increased by 29 per cent as a result of livestock and fertiliser since 1990. This had led to a 12 per cent increase in nitrogen levels in rivers.
"The greatest impact of excessive nitrogen in New Zealand rivers is nuisance slime and algae growth," the report said.
Waikato Regional Council was making efforts to preserve the region's environment, said chief executive Vaughan Payne, but he blamed central government's red tape for slowing down the process.
"Basically under the Resource Management Act if we want to respond to environmental trends, we have found it takes us six to seven years, and the equivalent in money, so $6 million to $7 million."
"It's not a very agile process, even if it's a simple change."
The report shows over-fishing has decreased sharply, carbon-monoxide emissions from transport have reduced, and a shift to cleaner home heating had seen "significant" improvements in air quality.
Despite overall decreases, road vehicle emissions in Hamilton, Auckland, Wellington and Christchurch still exceed recommended standards, the report said.
"Our main focus around air quality has been in places like Tokoroa where we are breaching national standards," Payne said.
"It's pretty hard if the source [of emissions] is vehicles - we are pretty much powerless to limit vehicles on the road."
As part of the report's release, a website displaying environmental indicators has also been set up.
The report will next be released in 2018, and is expected to be released every three years afterwards.