The Climate Change Minister has been told New Zealand is not on track to meet its target of reducing net greenhouse emissions to half of 2005 levels by 2030.
A briefing from environment officials says planet-heating gases have fallen 6 percent since their peak in 2006, while air temperatures, ocean acidity and sea temperatures have been rising.
Two droughts in the summers of 2008 and 2013 alone cost the rural sector $4.8 billion.
Minister Simon Watts was told Aotearoa's international climate commitment for 2030 required significantly greater emissions cuts than were required by domestic legislation.
He was told the government needed to decide whether to scale up domestic action, or move ahead with international negotiations to buy carbon credits.
The new government has previously been wary of committing to buying international credits, but meeting the entire target with carbon cuts here would be big task and major change of direction.
The previous government was planning to begin signing deals with countries in Asia and the Pacific within the next four years, to pay for projects (renewable energy and the like) that would count towards meeting New Zealand's 2030 international climate target. That would have helped fill the shortfall at home.
Labour was also talking about ramping up actions inside Aotearoa, for example native tree planting. That might have reduced the size of the overseas bill.
Treasury has put the cost of buying credits from overseas - for the estimated 100 million tonnes in carbon cuts needed - at anywhere between $3.3b and more than $23b between now and 2030, meaning, even at the lower end of projections, it could work out at around $500 million a year. It would still likely be cheaper and easier than making changes quickly inside Aotearoa, according to modelling by the Climate Change Commission.
The latest briefing also showed environmental spending was under pressure, with the Ministry for the Environment reviewing its operating model to save money.
Spending specifically on climate change was more stable.
However, funding capability for the independent Climate Change Commission was listed as a "key risk", as it heads into a busy year of advising on emissions plans, farming gases and other matters.