About

New Zealand’s Environmental Reporting Series:

Environmental indicators Te taiao Aotearoa

Environmental indicators Te taiao Aotearoa is part of New Zealand’s Environmental Reporting Series produced by the Ministry for the Environment and Statistics New Zealand.

The series consists of:

  1. Environmental indicators Te taiao Aotearoa, with statistical measures and trends on topics that relate to the five domains of our environment – air, atmosphere and climate, fresh water, land, and marine – and the cross-domain area of biodiversity.
  2. Environmental reports
    • 2014 Air domain report was the first domain report of the series. We will publish a report on 1 of the 5 environmental domains every six months.
    • Environment Aotearoa 2015, which summarises the state of all domains, is the first synthesis report in the series. We will publish synthesis reports every three years.
    • Environment Aotearoa 2015 – infographic is a visual summary of the key findings from Environment Aotearoa 2015.
    • Our marine environment 2016 presents information on the changes in New Zealand's marine environment over time, and the associated pressures and impacts contributing to these changes.
    • New Zealand's marine environment at a glance presents key points from Our marine environment 2016 in a single, engaging, and informative graphic for use online or as a printed poster.
    • Our fresh water 2017 presents information on the changes in New Zealand's fresh water environment over time, and the associated pressures and impacts contributing to these changes.
    • New Zealand's fresh water at a glance presents key points from Our fresh water 2017 in a single, engaging, and informative graphic for use online or as a printed poster.
    • Our atmosphere and climate presents information on the changes in the atmosphere and New Zealand's climate over time, and the associated pressures and impacts contributing to these changes.
    • Our land 2018 presents information on the changes in New Zealand's land environment over time, and the associated pressures and impacts contributing to these changes.
  3. Data files
    Underlying data are available from the Ministry for the Environment’s data service. These CSV, Excel, and geospatial files, along with associated metadata, support the key findings presented on the indicators website. 

 

About the domains

The data used for our reporting purposes has been gathered from a range of sources and, unless otherwise stated, covers the North and South islands of New Zealand.

The series covers the following environmental domains.

 The air domain comprises the shallow gas layer that surrounds Earth above ground level. This gas layer is made up mainly of oxygen and nitrogen as well as small amounts of other gases, vapour and particulates. The air domain excludes stratospheric ozone and the effects of greenhouse gases on Earth’s climate. These aspects are included in the atmosphere and climate domain.

 The atmosphere and climate domain extends from the air layer through the first two layers of Earth’s atmosphere – the troposphere and the stratosphere. The stratosphere includes greenhouse gases and stratospheric ozone, particulates, and meteorological conditions. Atmospheric conditions affect our climate. Climate includes temperature, humidity, atmospheric pressure, wind, precipitation, (rain, hail, sleet, and snow), solar radiation from ultraviolet light, and other weather patterns in a region over long periods. Localised air quality is considered in the air domain.

 The freshwater domain covers the water that runs across and under land areas. Fresh water relates to all the physical forms of unsalted water, including those in rivers, lakes, streams, ponds, wetlands, aquifers, and glaciers. The freshwater domain excludes atmospheric water, sea water (included in the marine domain), and geothermal water.

 The land domain comprises the soil, the underlying rock, and what is on the land. It includes what resides on top of and relies on the land (eg vegetation and land use from farming to urban development).

 The marine domain begins at the high-tide mark along our coastline and extends to the outer limits of New Zealand's exclusive economic zone including our continental shelf. It also includes estuaries, the seabed, and subsoil.

The cross-domain area of biodiversity covers our indigenous (native) plant and animal species of the land, freshwater, and marine environments. It also considers exotic plant and animal species (pest plants and animals as well as farmed plants and animals).

 

About the pressure-state-impact framework

New Zealand’s Environmental Reporting Series reports on three types of information:

  1. Why the environment is in this condition (pressure): the natural or human influences on the state of the environment. Pressures can explain changes in the state of an environment. For example, global greenhouse gas emissions from human activities are a pressure because they affect the state of greenhouse gas concentrations over New Zealand.
  2. The condition of the environment (state): the physical, chemical, and biological characteristics of the environment and how these characteristics are changing. For example, concentrations of a particular air pollutant indicate the state of the air domain – including changes in that state over time.
  3. What the condition of the environment means for us (impact): the ecological, economic, social, and cultural consequences of changes in the state of the environment. For example, changes in river water quality can affect animal and plant life in our rivers and the recreational opportunities for us in the environment.

 

About the topics and statistics

Technical experts developed the topics and statistics presented in Environmental indicators Te taiao Aotearoa. The topics identify the key issues we want to know about the environment, while the statistics are the measures for those topics.

The Ministers for the Environment and Statistics approved the topics. The Government Statistician approved the statistics.

Topics

The topics set the scope for reporting on environmental issues over the medium to long term. They help us answer high-level questions about the state, pressures, and impacts for each domain.

Environmental indicators Te taiao Aotearoa addresses a broad range of topics, for example: airborne gases of concern to human health; global emissions of greenhouse gases and ozone-depleting substances; urban freshwater use; soil types, and ocean acidity.

Statistical measures

Each indicator reports on our analysis of datasets (or statistic or set of statistics) about a specific topic. We assessed these statistics as either a national indicator, case study, or supporting information.

  • National indicator: the statistic is representative of the national situation and is highly accurate. A national indicator is directly relevant to a particular topic. 

  • Case study: the statistic relates to areas that represent only part of the national situation, may not be as accurate as desired due to methodological reasons, or only provides partial information about a topic. A case study, at the least, is reasonably relevant to a particular topic. 

  •  Supporting information: the statistic provides only contextual information, or may only inform a topic indirectly. Supporting information are still reasonably accurate.

 

About data quality

We use six criteria to assess data quality.

  • Relevance
  • Accuracy
  • Timeliness
  • Accessibility
  • Coherence
  • Interpretability.

Fitness for purpose (or appropriateness) is another key factor in assessing the quality of the data we analyse.

Relevance and accuracy are the main criteria we use to determine whether a statistic will be assessed as a national indicator, case study, or supporting information.

1. Relevance 

How well the data relate to a topic. Relevance includes level of detail, how long the data have been collected, where they were collected from, and the credibility of data collectors.

There are three levels of relevance. 

 Direct measure

Covers all aspects of a topic and is highly relevant to the topic. Often, direct measures form national indicators. For example, the national temperature time series is a direct measure of the ‘national and regional temperature’ topic. Measures that are estimated using modelling may still be considered ‘direct measures’ because the estimates directly inform the topic, even though they are measured indirectly.

 Partial measure

Covers only part of the topic and is reasonably relevant. Partial measures generally form case studies. For example, the case study about changes in the conservation status of indigenous species is a partial measure of the ‘impacts on biodiversity’ topic. Many other factors also affect the ‘impacts on biodiversity’ topic.

 Indirect measure

May be very accurate, but the data may not relate specifically to the topic or they support only one minor area of it. Indirect measures often form supporting information. For example, supporting information about the occurrence of skin cancer is an indirect measure of the ‘chronic health effects related to our changing climate’ topic. Other factors, such as behaviour or skin type, also affect skin cancer rates.

 

2. Accuracy

How well the data measure what they were designed to measure.

There are two levels of accuracy.

 High accuracy

The data are from a highly reliable source that uses highly reliable collection methods. A national indicator will have high-accuracy data.

 Medium accuracy

The data are from an acceptably reliable source that uses acceptable collection methods. The data measure what they were designed to measure, but may have limitations that may affect their robustness. A case study has at least medium-accuracy data.

We do not include low-accuracy data in Environmental indicators Te taiao Aotearoa.

 

3. Timeliness 

The time taken from collecting the data to publication 

 

4. Accessibility 

How easy it is to access and understand the data and any supporting information.

 

5. Coherence and consistency 

How well the data align with local and international data and methods. We also consider how easy it is to compare data over different time periods, so that trends in the statistic can be assessed.

Coherence and consistency with international data may be less important if the data relate to a topic specific to New Zealand.

 

6. Interpretability 

How easy it is to understand and use the data effectively. Ease of access to supplementary information and metadata improves data interpretability.

 

About trends

Statistical trends occur when the data show a generally increasing or decreasing change over time. A trend is a pattern in a dataset after accounting for cyclical, seasonal, and random variation.

A long-term time series may highlight a single long-term trend or a number of trends over shorter time periods. Trends may be linear or reflect the overall direction of change over time.

Trends do not show what is driving a change.  

Trend assessments

We assess trends for time series with at least six consecutive years of data points and where we are confident in the accuracy of the data. The trend icons below show the outcomes of trend assessments and the background colour denotes whether the direction of change is improving (green) or deteriorating (red) in terms of environmental quality. When the change cannot be easily interpreted as showing a change in environmental quality, we use a blue background.

We use the 95 percent confidence level (α = 0.05) to determine whether the data show an increasing or decreasing trend. If the P-value is greater than α, then we conclude that there are insufficient data to determine the trend direction with confidence.

 

Trend symbols

We use the following symbols to summarise a trend’s direction.

 Increasing trend: an analysis of the time series shows an upward trend at the 95 percent confidence level. Increasing trends that reflect improving environmental quality have green backgrounds. Increasing trends reflecting deteriorating environmental quality have red backgrounds.

 Decreasing trend: an analysis of the time series shows a downward trend at the 95 percent confidence level. Decreasing trends that reflect improving environmental quality have green backgrounds. Decreasing trends reflecting deteriorating environmental quality have red backgrounds.

 Indeterminate trend: an increasing or decreasing trend could not be identified with confidence due to insufficient data. This may be because of high variability in the data or because the data are constant over time; it may also reflect a wide distribution of trends across sites.

 Trend not assessed: a trend could not be tested because of the limited amount of data.

See Trend assessment – technical information for more details on trend assessment and characteristics.

 

Data providers

Unless otherwise stated, the data we used cover the North and South islands of New Zealand and come from the following sources.

Auckland Council, Bay of Plenty Regional Council, Department of Conservation, Environet and Golder Associates, Environment Canterbury, Environment Southland, GNS Science International, Greater Wellington Regional Council, Hawke’s Bay Regional Council, Horizons Regional Council, Landcare Research, Marlborough District Council, MetService, Ministry for the Environment, Ministry for Primary Industries, Ministry of Transport, Nelson City Council, New Zealand Transport Agency, NIWA, Northland Regional Council, Otago Regional Council, Statistics New Zealand, Taranaki Regional Council, Tasman District Council, Transpower New Zealand, University of Otago, Waikato Regional Council, Wellington Regional Council, West Coast Regional Council.

 

Updated 19 April 2018

  • Trend assessment – technical information

    This web page provides a summary of how we determined the methodologies for assessing the trends presented in Environmental indicators Te taiao Aotearoa. It is intended for a technical audience familiar with statistical trend assessments.
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