Appendix II: Background
What is climate change?
Over millions of years, our climate has undergone many changes - from ice ages to tropical heat and back again. Natural changes have generally been gradual, allowing people and other species to adapt or migrate, although some prehistoric climate changes may have led to the mass extinction of species.
Greenhouse gases trap the warmth from the sun and make life on Earth possible. Without them, too much heat would escape and the surface of the planet would freeze. However, over the previous 50 to 100 years, the concentration of the greenhouse gases carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) in the atmosphere has been increasing. The concentration of CO2 has increased 31% since 1750, the concentration of CH4 has increased 151% and the concentration of N2O has increased 17% (IPCC, 2001). The increased concentration produces an 'enhanced greenhouse effect' that causes Earth to heat up (i.e. global warming) and the climate to change. The Intergovernmental Panel on Climate Change (IPCC) 3rd assessment report (IPCC, 2001) notes that the effects of climate change due to the 'enhanced greenhouse effect' will be different in different parts of the world. However, in general, temperatures and sea levels are expected to rise, rainfall patterns may change in many areas, and the frequency of extreme weather events are expected to increase. The IPCC concluded the most of the observed warming over the past 50 years is likely to be due to the emission of greenhouse gases by human activities, and that the changes ahead of us will happen more quickly than any recent natural climate variations.
The UNFCCC & the Kyoto Protocol
In 1990, the Intergovernmental Panel on Climate Change (IPCC) concluded that human-induced climate change was a real threat to our future. In response, the United Nations General Assembly convened a series of meetings that culminated in the adoption of the United Nations Framework Convention on Climate Change (UNFCCC) at the 'Earth Summit' in Rio de Janeiro in May 1992. The UNFCCC took effect on 21 March 1994 and has been signed and ratified by 188 nations, including New Zealand.
The main objective of the UNFCCC is to achieve stabilisation of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic (caused by humans) interference with the climate system. Such a level should be achieved within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner.
All countries that ratify the UNFCCC are required to address climate change through greenhouse gas inventories, national or regional programmes and preparing for adaptation to the impacts of climate change. Developed countries agreed to non-binding targets to reduce greenhouse gas emissions to 1990 levels by 2000. However, by 2000 only a few countries made appreciable progress towards achieving their targets. The international community recognised that the UNFCCC alone was not enough to ensure greenhouse gas levels would be reduced to safe levels, and that more urgent action was needed. In response, the Parties to the UNFCCC negotiated the Kyoto Protocol.
The Kyoto Protocol aims to reduce the total greenhouse gas emissions of developed countries (and countries with economies in transition) to 5% below the level they were in 1990. The Protocol sets reduction targets for the greenhouse gas emissions of developed countries for the period 2008 to 2012, referred to as the first commitment period. Different countries have different targets to achieve. New Zealand's target is to reduce its greenhouse gas emissions to the level they were in 1990 or take responsibility for any excess emissions.
The Protocol has to be signed and ratified by 55 countries (including those responsible for at least 55% of the developed world's 1990 CO2 emissions) before it can enter into force. As at July 2004, 123 countries accounting for 44.2% of CO2 emissions in 1990 have ratified the Protocol. New Zealand ratified the Kyoto Protocol on 19 December 2002.
