As it becomes increasingly difficult to dispose of New Zealand's waste overseas, domestic recycling and waste management has become a pressing issue. The current government banned plastic bags and increased spending on recycling programmes. Some parties advocate incineration to deal with the growing waste problem.

There is little dispute between the parties that New Zealand's rivers and lakes are in crisis, with most no longer fit for swimming. But with a major export-earner, agriculture, the main factor in this problem, there are powerful interests at play and rules to protect waterways have been resisted.

An island nation, New Zealand has one of the largest exclusive economic zones in the world. As our oceans come under increasing pressure from overfishing and a changing climate, many argue that further intervention is needed to protect ocean ecosystems.

Last year the government passed the Zero Carbon Act with support from all parties in parliament except ACT. The law sets NZ a target of limiting global warming to 1.5C – the threshold at which the worst effects of climate change start to kick in. But some say that current measures aren't enough to even curb heating below 2C. An ongoing dispute is how agriculture should be treated – the country's main export-earner is also a major source of emissions.

Around a third of all land in New Zealand is publicly owned and protected, most of it by the Department of Conservation. The department's use of 1080 to control pests has long been controversial, but a new issue has arisen this election with a proposed cull of tahr, a favourite among some hunters.

The New Zealand way of life will change as extreme weather events and other effects of climate change become the new normal. Cities and towns across the country will need to adapt to deal with droughts and rising sea levels.