The Parliamentary Commissioner for the Environment has warned that ambitious management of tourism is urgently needed to address growing pressure on the environment.
In his report, titled "Pristine, popular ... imperilled? The environmental consequences of projected tourism growth", Simon Upton paints a picture of the environmental consequences of forecast tourism growth in New Zealand to 2050, based on extended estimations of current visitor trends.
Tourists are defined as international visitors and locals who are away from home for at least a night in the report.
Mr Upton forecasts that by 2050 international visitors will potentially exceed 10 million people per year, up from 3.9 million people per year currently.
Environmental pressures from tourism include loss of natural isolation, degrading water, increased waste, increasing infrastructure and loss of landscape, loss of flora and fauna, biosecurity risk and emissions.
An increased threat of foreign species being introduced, increased challenges for Māori, tourism destinations operating at or close to full capacity, and the loss of 'the tranquillity and isolation that made those places worth visiting in the first instance' are outcomes Mr Upton predicts will occur in the future, unless greater action to protect the environment is taken.
"Despite many soothing words about sustainability over the two intervening decades, we haven't significantly shifted from an extractive path dependency," the Commissioner stated in the report overview.
"Recent initiatives such as the International Visitor Conservation and Tourism Levy and the development of destination management plans are promising, but considerably more ambition will be required if a continued worsening of tourism-related environmental pressures is to be avoided," he said.
Mr Upton said while most risks can be managed, climate change is a greater challenge that "could have a significant and long-term effect on New Zealand's tourism sector".
Mr Upton said New Zealand's environment is a drawcard for tourists and any worsening of the country will affect demand.
"Promoting the natural environment can be a double-edged sword," he said.
Mr Upton said tourism needed to be carried out in line with Te Tiriti o Waitangi and reflect the environmental values of Kiwis.
He said the public is starting to notice the pressures on the environment from tourism and is questioning the benefits of this growing industry.
"The evolution of this tension between economic opportunities and environmental and cultural harm will largely determine the industry's social licence to operate in the future," he said.
MBIE tourism general manager Iain Cossar said tourism is the country's largest export earner, providing jobs and facilities.
"There is a need for a fuller understanding and better management of the impacts and costs of tourism on communities and the environment for tourism to benefit all New Zealand," he said in a statement.
Mr Cossar said MBIE, DOC and the Ministry for the Environment, along with the tourism sector, are working to address the effects of tourism growth on New Zealand communities.
"To ensure that tourism can positively contribute to communities and the natural environment we're already rolling out collaborative visitor and destination management strategies and campaigns advocating and encouraging responsible visitor behaviour, in addition to creating a sustainable funding approach."
Tourism Minister Kelvin Davis said the report is an endorsement of sustainability initiatives the Government's introduced.
"We're doing a lot, a heck of a lot already," he said.
-Annual tourist spend for the year to March 2018 was $39 billion ($23 billion local, $16.2 international visitors).
-Auckland, Wellington, Christchurch and Queenstown-Lakes have the highest tourist spend.
-By 2023, Milford Sound Piopiotahi is expected to have 1.2 million visitors each year, up from 946,000.
-The most international visitors come from Australia, with 1.5 million people this year.