Message to our readers

New Zealand’s Environmental Reporting Series: Our atmosphere and climate 2017 is the first report in the series dedicated to our atmosphere and climate. It does not cover air quality because air, the shallow gas layer closest to Earth, is considered a separate domain, which we have reported on in the 2014 Air domain report.

Unsurprisingly, the dominant issue for atmosphere and climate is human-induced climate change. New Zealand’s atmosphere and climate are part of a complex Earth system that is being changed by global greenhouse gas emissions from human activities, largely from burning fossil fuels. This report is not an assessment of the science of climate change; that has been done comprehensively in other places, such as in reports by the Intergovernmental Panel on Climate Change. Rather, in line with the aims of the Environmental Reporting Act 2015, the report summarises indicators of climate change in New Zealand.

Data to 2013 show gross global greenhouse gas emissions increased 51 percent from 1990 to 2013. New Zealand contributed to this trend, with a 24 percent increase in our gross greenhouse gas emissions from 1990 to 2015. Most of this increase occurred before 2005.

As greenhouse gas emissions have increased globally, so too have concentrations of those gases in the atmosphere, thus warming the planet. New Zealand’s annual average land temperature has increased 1 degree Celsius since 1909. This is in line with global increases and is reflected, for example, in more warm days and fewer frosts at about one-third of sites around the country over the period 1972–2016.

New Zealand’s climate will continue to warm in the short term due to the cumulative effect of past emissions of greenhouse gases, such as carbon dioxide, which can persist in the atmosphere for thousands of years. However, the climate changes that our children and grandchildren will experience depend on the effectiveness of current worldwide actions to reduce emissions.

While this report is not primarily about future climate projections, scientists have warned that the greater the magnitude of warming in the climate system, the greater the risk of severe and pervasive negative impacts on people and the environment. We hope this report contributes to people, governments, and businesses making good decisions for future generations.

The report also discusses New Zealand’s ultraviolet (UV) radiation levels and the risk of skin damage, including skin cancer, from exposure to high UV levels. Our UV levels fluctuate over the year but are high in summer and contribute to New Zealand’s high rates of melanoma. The ozone layer in the atmosphere is important in controlling the levels of UV radiation that reach Earth’s surface. The 1987 Montreal Protocol heralded an international agreement to minimise the damaging effect of ozone-depleting substances on the ozone layer.

The production of these harmful substances fell by 98 percent from 1986 to 2015. New Zealand has both contributed to and benefited from the decline in the production of these substances. Moreover, the effective management of this issue is a heartening example of how, in the face of data and other evidence, we can come together internationally to constrain damaging human activities and prevent the serious consequences of higher UV levels.