New Zealand’s Environmental Reporting Series: Environment Aotearoa 2015 presents information on five environmental domains: air, atmosphere and climate, fresh water, land, and marine. Biodiversity is also included as a cross-domain theme.
The framework for the series is set out in the Environmental Reporting Act 2015. Reports will present information on the state of the environment and how it is changing over time, the natural or human pressures that influence this state, and the ecological, economic, social, and cultural consequences of changes in the state of the environment.
The reports do not include possible responses to the issues raised, to ensure separation between environmental reporting and policy decisions. Instead, environmental reporting provides the basis for discussions at both the national and local levels about how to best respond to the environmental issues New Zealand faces.
Here is an overview of each domain.
Most New Zealanders enjoy good air quality most of the time. When air quality reaches levels considered unhealthy, this usually happens for limited periods in specific locations. The air pollutant of most concern from a health perspective is particulate matter – the tiny airborne particles that affect respiratory and cardiovascular health. Damage to respiratory and cardiovascular systems can lead to hospital admissions, days of work lost, and shorter lives for some New Zealanders.
- Burning wood and coal for home heating is the primary source of pollutants that cause most concern. It contributes 58 percent to annual emissions of human-made particulate matter in our air. This is a problem mainly in winter, in places where households use wood or coal to keep their homes warm.
- Air quality showed a significant improvement since 2006, driven mainly by the shift to cleaner home heating.
- Between 2001 and 2013, estimated emissions for five key pollutants from road vehicles fell between 26 and 52 percent, due to improvements to fuel, and stricter emission limits on new vehicles.
- In 2012, an estimated 1,000 premature deaths were associated with particulate matter in our air, 14 percent fewer than in 2006.
New Zealand’s temperate climate shapes and supports our natural environment, economy, and way of life. Our climate is naturally variable because of our location in the South Pacific Ocean and our small, but mountainous, land area. However, our climate is changing, and this has the potential to affect our economy, and marine and other ecosystems.
- The biggest driver of change is the increase in global greenhouse gases in the atmosphere. Global net emissions of greenhouse gases rose 33 percent since 1990. Between 1990 and 2011, New Zealand emitted around 0.1 percent of global emissions. New Zealand’s greenhouse gas emissions increased 42 percent between 1990 and 2013.
- Carbon dioxide is the greenhouse gas that has the greatest impact over the long term. Over New Zealand, carbon dioxide concentrations increased 21 percent since 1972.
- New Zealand’s temperature increased around 0.9 degrees Celsius in the past 100 years, almost certainly due to the increase in greenhouse gases in the atmosphere.
- We have high ultraviolet light levels in New Zealand. Our rates of skin cancer (melanoma) incidence are one of the highest in the world partly because of our high level of exposure to ultraviolet light.
The condition of our lakes, rivers, streams, wetlands, and groundwater is important for a number of reasons. For Māori, fresh water is a taonga and essential to life and identity. Our economy depends on having plentiful water – agriculture, tourism, and hydroelectricity generation particularly rely on water. New Zealanders and tourists enjoy many forms of recreation that use our lakes and rivers, such as swimming, kayaking, and fishing. Our waterways also support many indigenous animals, plants, and ecosystems. Fresh water is primarily taken for hydroelectricity generation and irrigation for farms, and our fresh water quality depends mainly on the dominant land use in a catchment.
- Water quality is very good in areas with indigenous vegetation and less intensive use of land. Rivers in agricultural and urban areas have reduced water clarity and aquatic insect life, and higher levels of nutrients and Escherichia coli (E.coli) bacteria.
- The greatest impact of excessive nutrients in New Zealand rivers is nuisance slime and algae (periphyton) growth. This growth can impede river flows, block irrigation and water supply intakes, and smother riverbed habitats. Poor water clarity and elevated E.coli levels also affect our ability to use fresh water for recreation.
- Between 1990 and 2012, the estimated amount of nitrogen that leached into soil from agriculture increased 29 percent. This increase was mainly due to increases in dairy cattle numbers and nitrogen fertiliser. Once in the soil, excess nitrogen travels through soil and rock layers, ending up in groundwater, rivers, and lakes.
- Between 1989 and 2013, total nitrogen levels in rivers increased 12 percent, with 60 percent of monitored sites showing statistically significant increases. About 49 percent of monitored river sites have enough nitrogen to trigger nuisance periphyton growth, as long as there is enough sunlight, phosphorus, and a lack of flood events for periphyton to bloom. Phosphorus also triggers nuisance periphyton growth. About 32 percent of monitored sites have enough phosphorus to trigger this growth.
- High levels of nitrogen can also be harmful to fish; however, less than 1 percent of monitored river sites have nitrogen levels high enough to affect the growth of multiple fish species.
- Water clarity improved at two-thirds of monitored sites between 1989 and 2013. E.coli levels are higher in urban and pastoral areas, but meet acceptable standards for wading and boating at 98 percent of monitored sites.
Our land has undergone extensive change since human occupation 700 to 800 years ago, and particularly since European settlement in the 19th century. Today, agricultural and horticultural land occupies nearly 42 percent of New Zealand, while plantation forestry covers a further 7.5 percent. Indigenous forest covers about one-quarter of the country, concentrated mainly in upland and mountainous areas. Wetlands are reduced to about 10 percent of their original extent. The condition of our land affects its productivity for agriculture and other land-based industries. It also influences the health of our indigenous biodiversity and ecosystems.
- The extent of agricultural land has not changed substantially since 1996, but its use has become more intensive in a number of regions.
- The most critical issue affecting our land is erosion caused by human activity, particularly in the north and east of the North Island. Erosion reduces the productivity of the land and affects water quality, because it adds sediment and nutrients to waterways.
- A significant issue affecting our land is compaction. This is when soil is compressed, reducing the air pockets between soil particles, and making it harder for plants to grow. Over half the soils measured under dry stock (animals farmed for dairy, meat, wool, and velvet) and nearly 80 percent of soils under dairy farming are affected by compaction, which reduces the productivity of land.
- Pests are a serious threat to our indigenous animals, plants, and habitats. Possums, rats, and stoats are the most widespread of our pests – they are found across at least 94 percent of the country.
New Zealand has one of the most diverse marine environments in the world, because it encompasses subantarctic and subtropical waters. Our oceans support a wide range of habitats and sea life. Commercial harvesting is managed to ensure the sustainability of fisheries, but fishing methods that are damaging to the marine environment and bycatch (when an animal is caught unintentionally in fishing gear) are ongoing pressures on marine animals. The condition of our marine environment affects its productivity, as well as its ability to support marine life. Our marine environment is also important to New Zealanders from a recreational perspective, and for Māori, for whom it has long been a source of food and other resources.
- The most serious long-term pressures on our marine environment are likely to be caused by climate change. Coastal sea levels and long-term sea-surface temperatures around New Zealand have risen over the last century, and our oceans are more acidic than when measurements were first taken in 1998.
- Eight of our 30 indigenous marine mammal species are threatened with extinction. The extinction risk of one of these – the New Zealand sea lion – has increased in recent years. Māui’s dolphin is now one of the rarest marine mammals in the world, with an estimated 55 individuals over a year old remaining.
- Of the 92 indigenous seabird species and subspecies that breed in New Zealand, 35 percent are threatened with extinction. A further 55 percent are at risk of extinction. The risk of extinction has increased for seven seabird species in recent years.
- Between 2009 and 2014, the proportion of fish stocks subject to overfishing decreased from 25 percent to 14 percent. In 2014, more than 95 percent of fish caught were from stocks that are not overfished.