1 Background
Greenhouse gases
Greenhouse gases trap 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 past 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. Since 1750, the concentration of carbon dioxide has increased 31 percent, the concentration of methane has increased 151 percent and the concentration of nitrous oxide has increased 17 percent (Intergovernmental Panel on Climate Change, 2001) (4NC Figure 1). The increased concentration of these gases produces an "enhanced greenhouse effect" that decreases the amount of Earth's heat that is radiated back into space.
Increasing industrialisation over the past century is the major source of the increased concentration of greenhouse gases - carbon dioxide is released by burning fossil fuels such as coal, petrol and gas. They supply around 90 percent of the world's commercial energy needs. The carbon in these fuels, stored in the earth's crust over tens of thousands of years, is being released at a rapid pace. Other greenhouse gases like methane and nitrous oxide come from agricultural practices (cropping and livestock farming), waste disposal and industrial processes. The effects are made worse by the destruction of much of the world's forests, which reduces the amount of carbon dioxide absorbed from the atmosphere.
Climate change
The Earth's climate has undergone many changes over millions of years - 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 mass extinction of species. With the enhanced greenhouse effect (commonly referred to as global warming), the process and pace of change have increased.
The effects on the climate due to the "enhanced greenhouse effect" will be different in different parts of the world (Intergovernmental Panel on Climate Change, 2001). However in general, temperatures and sea levels are expected to rise, and the frequency of extreme weather events such as droughts and floods is expected to increase. The changes ahead of us are expected to be larger and to happen more quickly than any recent natural climate variations.
The effects are already measurable; examples include:
- 2004 was the fourth warmest year globally since records began in 1861
- the period from 1995 to 2004 has seen nine of the 10 warmest years on record, with only 1996 not making the "top 10"
- average global temperature has gone up by about 0.7°C since the end of the 19th century
- sea levels increased by about 10 to 20 centimetres between 1900 and 2000
- glaciers are retreating
- Arctic sea ice is thinning and reducing in extent
- 1998 was the world's - and New Zealand's - hottest year since records began.
4NC Figure 1: Human emissions have caused a strong rise in greenhouse gases concentrations over the past 100 years
There has been debate in the past on whether humans were responsible for the observed climate change, or whether it was just a case of natural variability. Recent worldwide observations and complex climate models have produced new and stronger evidence that most of the warming observed over the past 50 years is, in fact, due to human emissions of greenhouse gases. This finding by the Intergovernmental Panel on Climate Change (IPCC) was also supported by the American Academy of Sciences.
As the Earth's temperature continues to rise, the weather is expected to become more extreme. Projections of future global temperature suggest rises range from 1.4°C to 5.8°C over the next 100 years, depending on future greenhouse gas emissions ( 4NC Figure 2). This will mean higher maximum and minimum temperatures, more hot days and heat waves, and fewer cold spells nearly everywhere. Rainfall patterns are likely to change, and the variability of rainfall is expected to increase. This will lead to more frequent rain in some mid- and high latitude areas, but possible reductions in others. Large continental land areas will suffer from an increased risk of drought. Apart from gradual changes, extremely heavy rainfall could increase in severity and frequency. Tropical cyclone winds are likely to become more intense with heavier rainfall causing floods and property damage. Sea levels will continue to rise by between 0.1 metre and 1.0 metre by 2100, eroding coastlines and flooding low-lying areas. Sea levels will continue to rise for many more centuries, even after atmospheric temperatures have reached a new stable level.
In some parts of the world, we can already see changes in response to the increasing temperatures, with shifts in the habitat range for some plants and animals, and earlier flowering of trees. Glaciers are receding worldwide, and seasonal snow and ice cover has decreased in northern high latitudes. The growing season in mid- to high latitudes has increased by up to 11 days over the past 30 years.
Over the next 100 years, the expected rate of change in global average temperatures is likely to be larger than any natural variations in at least the past 10,000 years.
Developing countries will be worst affected by changing climate patterns. Many have land areas that are particularly sensitive to change and prone to floods or drought, and few resources to cope with negative impacts. Coastlines in poorer countries are more vulnerable to flooding - 49 of the 50 countries whose shore protection costs are likely to rise substantially are less developed countries.
Agriculture plays a larger part in the economies of developing countries, which makes them more vulnerable to climate extremes, and poorer nutrition and health care will mean higher loss of life. Many developing countries are also less able to adapt quickly to changes in climate because of a lack of technology, education, infrastructure and money.
International response: The United Nations Framework Convention on Climate Change (UNFCCC)
In 1990, the IPCC concluded that human-induced climate change was a 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 national or regional programmes to prepare for adaptation to the impacts of climate change, protect and enhance sinks (for example, forests), monitor emissions trends via greenhouse gas inventories and provide financial assistance to developing countries. Developed countries agreed to non-binding targets to reduce greenhouse gas emissions to 1990 levels by 2000.
International response: The Kyoto Protocol
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 First Conference of the Parties to the UNFCCC (COP1) launched a new round of talks for stronger and more detailed commitments for Annex I countries (that is, developed countries and countries with economies in transition). After two-and-a-half years of negotiations, the Kyoto Protocol was finalised in Kyoto, Japan on 11 December 1997. New Zealand ratified the Kyoto Protocol on 19 December 2002. The Protocol came into force on 16 February 2005.
The Kyoto Protocol shares the UNFCCC's objectives, principles and institutions, but significantly strengthens it by committing Annex I Parties to individual, legally-binding targets to limit or reduce their greenhouse gas emissions. Only Parties to the Convention that have also become Parties to the Protocol, by ratifying, accepting, approving, or acceding to it, are bound by the Protocol's commitments. Article 3 of the Kyoto Protocol states that the Parties that ratify the Protocol shall individually or jointly ensure that their aggregate anthropogenic greenhouse gas emissions do not exceed their "assigned amounts" with a view to reducing their overall emissions by at least five percent below 1990 levels in the first commitment period (2008-2012).
The "assigned amount" is the maximum amount of emissions (measured as the equivalent in carbon dioxide) that a Party may emit over the commitment period in order to comply with its emissions target. New Zealand's assigned amount is its gross [Gross emissions do not include emissions and removals from the land-use, land-use change and forestry sector (LULUCF).] emissions in 1990 multiplied by five (that is, the five years of the commitment period). New Zealand has to take responsibility for any emissions in excess of its assigned amount.
To achieve their targets, Annex I Parties must put in place domestic policies and measures to address emissions. Emissions may also be offset by increasing the amount of greenhouse gases removed from the atmosphere by carbon "sinks" in the land use, land-use change and forestry sector. The Kyoto Protocol also defined three "flexibility mechanisms" to lower the overall costs of achieving its emissions targets - the clean development mechanism, joint implementation, and emissions trading. These mechanisms enable Parties to access cost-effective opportunities to reduce emissions or to remove carbon from the atmosphere in other countries. While the cost of limiting emissions varies considerably from region to region, the benefit for the atmosphere is the same, wherever the action is taken.
Reporting under the UNFCCC and Kyoto Protocol
Under the UNFCCC (and the Kyoto Protocol), New Zealand is required to report a greenhouse gas inventory on an annual basis, and a national communication on a less frequent basis, the frequency being determined by the Conference of the Parties. New Zealand's Third National Communication was submitted to the UNFCCC in 2001 and underwent an in-depth review by an international team between May and November 2002, including an in-country visit from 23 to 28 June 2002. The main findings of the team's report (FCCC/IDR.3/NZL), published in March 2003, are contained in Box 1.
This is New Zealand's Fourth National Communication and is based on the revised guidelines for national communications from Annex I Parties adopted at the Fifth Conference of the Parties to the UNFCCC (FCCC/CP/1999/7). The Fourth National Communication reports on New Zealand's progress towards meeting its commitments under the UNFCCC since the end of 2001, and preparations for the first commitment period under the Kyoto Protocol.
Box 1: In-depth review of New Zealand's Third National Communication
The report on the in-depth review of New Zealand's Third National Communication noted the following:
- New Zealand broadly met the UNFCCC guidelines for national communications.
- Improvements in reporting had been made compared to the Second National Communication, particularly concerning information on greenhouse gas inventories and policies and measures.
- Presentation of information in the national communication could benefit from closer adherence to the UNFCCC guidelines, especially in projections, and policies and measures chapters.
- More analysis could be provided on the factors underlying the historical and future emission trends; such analysis is essential in the context of policies and measures where the monitoring of their effects could be given more attention.
- Although some of the policies may have helped slow the growth in emissions, the effect of these policies was outweighed by the growth in emissions from transport and energy use in industry.
- Other possible reasons for the emissions being higher in 2000 than in 1990 may include insufficient funding of the 1994 policy package, deferment of the consideration and introduction of the carbon charge envisaged in the package, and a reliance on voluntary approaches which did not fully achieve the outcome expected.
- The scale of activities, ambitious timetable and targeted approach the Government had adopted in preparing for the ratification of the Kyoto Protocol was acknowledged with appreciation.
- Also acknowledged was the role of the preferred policy package as a major step forward in the development of an integrated climate change strategy, in which both mitigation and adaptation are taken into account.
- Without the preferred policy package it will be difficult for New Zealand to reach its target under the Kyoto Protocol.
- The role of the National Energy Efficiency and Conservation Strategy was noted. It was also noted that the joint efforts of the Energy Efficiency and Conservation Authority and energy authorities could help to use the potential of non-traditional renewable sources, such as solar and wind energy, which could make a greater contribution to the already high share of renewables in the energy mix.
- New Zealand's efforts to fill key information gaps and uncertainties arising from estimates of carbon in the land-use change and forestry sector were commended, and the importance of this ongoing monitoring for domestic policy purposes and international reporting was noted.
