In 1988, international concern about global warming led to the establishment of the Intergovernmental Panel on Climate Change (IPCC). This group was to assess all the latest scientific, technical and socio-economic research on the topic. The IPCC’s Third Assessment Report in 2001 identified sufficient evidence to blame global warming on human activities. Scientists had carried out extensive modelling to understand the global climate, but were unable to reproduce the warming observed since 1950 without increasing carbon dioxide concentrations. Neither the natural variability of weather systems, nor changes in incoming solar radiation were shown to be sufficient to cause the observed changes.
New Zealand’s position
New Zealand, together with many other developed countries, is taking action to minimise greenhouse gas emissions and therefore reduce the effects of climate change. It has ratified the Kyoto Protocol, researched emission reduction, and struck up international partnerships (with, for example, Australia and the US) in order to collaborate and exchange ideas. Many of New Zealand’s local and regional governments are involved in initiatives.
The prediction by scientists in the 1970s of an impending ice age is often raised by skeptics to discredit talk of global warming. However, the cooling was calculated to occur gradually, reaching glacial conditions in 20,000 years’ time. This long-term cooling would be due to natural variations in earth’s orbit of the sun. By contrast, global warming is largely a consequence of human activity.
Just under half of New Zealand’s total greenhouse gases are produced by agriculture in the form of methane and nitrous oxide. The agricultural sources of methane are ruminant animals like sheep and cows, while nitrous oxide is produced in the soil by bacterial breakdown of animal excreta and nitrogenous fertilisers. Forty-three per cent of emissions come from carbon dioxide produced by the energy sector (mainly transport and electricity generation). Industrial processes and waste account for 8%. On the upside, New Zealand's abundant forests help to absorb carbon dioxide from the atmosphere. However, New Zealand's total emission of greenhouse gases is estimated to have increased by about 21% from 1990 to 2004.
The Kyoto Protocol
Developed from the earlier United Nations Framework Convention on Climate Change, the Kyoto Protocol is an international agreement to address global warming and delay climate change. It aims to reduce the total greenhouse emissions of participating countries to below their 1990 levels by 2012. However, each country has its own target – New Zealand’s is to reduce emissions to the same level they were in 1990.
The Kyoto Protocol was designed as a first step towards a future with lower emissions. While targets beyond 2012 have not yet been agreed, it is clear that greater cuts in greenhouse gases and broader participation will be needed.
Research conducted by New Zealand’s government, education and private sectors aims to understand how sensitive the country is to climate change and variability. In addition, there are a number of initiatives to reduce emissions. These include strategies to improve energy efficiency, increase renewable energy sources, use more energy-efficient transport, and reduce emissions from landfills.