Peter Usher Climate Unit, United Nations Environment Programme, Nairobi
The atmospheric environment is under threat from anthropogenic emissions of pollutants and greenhouse gases to the extent that irreversible changes to the climate, the ozone layer and the quality of the air we breathe could occur.
However, considerable scientific uncertainty remains with regard to the extent and magnitude of the change in climate as a result of human activities, and the impacts of such change. The natural variability of climate makes assessment of the human induced climate change difficult. Even if the magnitude of global warming from greenhouse gases in the atmosphere could be defined the impacts of this global average warming on, for example, the sea-level; the weather patterns such as rainfall, cloudiness, storms and droughts; agriculture; and marine and terrestrial eco-systems would have to be defined on regional, national and local scales. The assessments of these environmental impacts are, in turn, necessary for estimating the socio-economic impacts of environmental changes. Before taking action, the policy-makers and other decision makers require the results of such impact assessments to be defined with greater certainty than what is scientifically possible to state at present.
At the same time there is a backlash by those who favour inaction, asserting that human activities do not affect the climate or cause global warming in any significant way. There may be people who are drawn to believe this, particularly when in some parts of the world very cold weather has been experienced in recent years coincident with the discussions on global warming. However, what we know for certain is that human activities are altering the composition of the atmosphere from its natural state, and that we are facing a risk of adverse changes in the environment because of it. The extreme weather events may well be influenced by the imbalance created in the earth's atmospheric composition.
This paper gives an overview of the international actions in combatting climate change and some information on the status of science on the climate change and its impacts.
The Intergovernmental Panel on Climate Change (IPCC) was jointly established by the World Meteorological Organization (WMO) and the United Nations Environmental Programme (UNEP) in 1988. The IPCC formed three Working Groups:
A Special Committee on the Participation of Developing Countries was also established under the IPCC to promote the participation of developing countries' experts in the IPCC activities.
The IPCC First Assessment Report was completed in August 1990. It consists of:
In 1992 the IPCC and its Working Groups updated their 1990 reports, addressing the key conclusions in light of new data and analyses so that latest information on the climate change issue was available for the negotiations on the Framework Convention on Climate Change as well as for the United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro (June 1992).
The Panel's Eighth Session held in Harare in November 1992, adopted a new structure for the Working Groups in the light of the needs for additional information to support and facilitate the negotiations taking place under the Climate Convention. The task of the Working Groups, in particular Working Groups II and III, were changed as follows:
It is under this new structure that the IPCC is now undertaking a Second Assessment which would result in a Special Report of the IPCC to the First Session of the Conference of the Parties to the Framework Convention on Climate Change and the IPCC Second Assessment Report. The special report is expected to be completed in November 1994 and the Second Assessment Report in late 1995.
The IPCC assessments culminate from a coordinated effort by hundreds of experts worldwide, under the Chairmanship of Professor Bert Bolin. All Member States of the United Nations are members of the IPCC and have the right to participate in all its decisions. These decisions are normally made during the plenary sessions of the Panel to which all members are invited. Inter-sessional decisions are made by a 28 member Bureau, established in Harare in November 1992. The Bureau members consist of representatives of 13 developed countries, 14 developing and 1 country with economies in transition, in order to ensure an equitable geographic balance.
The reports of IPCC present an unbiased scientific assessment of the climate system, its propensity for change, the impacts of such changes and the range of responses to mitigate or adapt to such changes. The IPCC assessment constitutes the most authoritative statement on climate change available and its reports have become a standard work of reference used by all those concerned with the issue of climate change - policymakers, scientists and other experts. (Section 4 below is based on the results of the IPCC assessment.)
The Framework Convention on Climate Change was adopted by the Intergovernmental Negotiating Committee on 9 May 1992, just in time for the treaty to be signed by Governments at the United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro in June 1992. 154 States and the European Community signed the Convention, reflecting wide recognition that climate change is a problem that must be tackled through international cooperation. Upon ratification by 50 States, the Convention entered into force on 21 March 1994. The First Session of the Conference of the Parties to the Convention will take place in Berlin in March 1995.
The Convention provides a framework for Governments to work together to achieve the ultimate objective of stabilizing the greenhouse gas concentration in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. The special situation of different groups of countries are recognized and taken into consideration under the Convention.
Some of the commitments under the Convention that every country Party to the Convention is expected to implement include:
There are no mandatory emission reductions specified in the Convention that apply to all Parties to the Convention. However, the commitment of the developed countries include a target emission reduction of greenhouse gas emission to the 1990 levels by the year 2000. Further negotiations are expected to be negotiated under the Convention and be adopted as Protocols or as an amendment or an annex to the Convention. The countries' strategies to mitigate climate change through reduction of the emission of greenhouse gases may include regulation of emission from industry and transport sectors, and efficiency improvements in energy supply and utilization. Implementation of such strategies will not be cost free but there are advantages to be gained. Adoption of energy efficient technologies can often be self-financing and will provide opportunities for innovative technological development, expansion in business and implementation of cooperative, environmentally sound joint projects. Net emission can also be promoted through carbon sink enhancement, for example, through afforestation and reforestation programmes. Secondary benefits such as preservation of biodiversity and prevention of soil erosion make sustainable forest management attractive as no-regret policies.
World Climate Programme (WCP) was initiated in 1979 by the World Meteorological Organization (WMO) in collaboration with UNEP and International Council of Scientific Unions (ICSU). The WCP was formally established by the Eighth World Meteorological Congress in April/May 1979, as a follow up of the First World Climate Conference held in February 1979, at which "The Declaration of the World Climate Conference" was adopted. The Declaration urged the nations of the world to take full advantage of the present knowledge of climate, to take steps to improve that knowledge and to foresee and to prevent potential adverse man-made changes in climate.
The WCP was conceived with a principal objective of assisting countries in the application of climate knowledge; and providing information on possible future climate variations and change to governments, industry and the general public. The purpose and the main objective of the WCP remained generally unchanged during the years of its implementation. The WCP is organized into four sub-programmes:
The World Climate Data and Monitoring Programme (WCDMP)
The purpose of this component of WCP is to improve the availability of reliable data for the purpose of the WCP. Improving the availability of data involves maintenance and, as necessary, enhancement of many kinds of observational networks, as well as facilities for data processing and exchange. Further, climate data should be analyzed and presented in the form of products to allow documenting the world-wide climate, assessing climate variability and trends, and using climate data for applications to many resource management and socio-economic activities.
There are five projects which, when viewed in their entirety, provide the Members with a coordinated complete climate management programme consisting, on the one hand, of automated database construction and management, and on the other hand, of climate system monitoring and climate change detection. The aim is to build capabilities and interpret climate data bases and thus bridge the gap between developed and developing countries.
WMO is responsible for the implementation of WCDMP, and UNEP, UNESCO and its IOC and ICSU participate and support the programme.
The World Climate Applications and Services Programme (WCASP)
This component of WCP was established in recognition of the importance of application of climate information in reducing the vulnerability of society to climate extremes, and the need for improvement of data and expertise to provide such services, particularly in developing countries. The purpose of WCASP is to promote applications of existing climate information to the priority areas of food, water, energy, planning and management of land use, urban areas, forests, oceans and coastal zones, buildings, as well as to other sectors such as human health, transport and tourism. Emphasis is placed on methods of adaptation to and mitigation of, adverse impacts of climate and its variations, leading also to improved awareness of the potential benefits of climate application and services and improved access to practical techniques for applications of climate information and knowledge.
WMO assumes the lead responsibility for WCASP. A number of water-related projects are implemented under WCP-water and are coordinated by WMO and UNESCO.
The World Climate Research Programme (WCRP)
The objective of WCRP is to provide the organizational framework for international cooperative research projects aiming to understand the physical climate system and the causes of climatic variability and climate change. This requires a quantitative understanding of the four main components of the physical climate system: the global atmosphere, the world ocean, the cryosphere (comprises the continental ice-sheets/caps, mountain glaciers and sea-ice) and the land-surface. National and international contributions are made towards various activities that are organized into manageable multi-disciplinary projects/experiments.
The World Climate Impact Assessment and Response Strategies Programme (WCIRP)
Initially this programme was called the World Climate Impact Studies Programme (WCIP), overall objective of which was to assess the sensitivity of socio-economic sectors to climate variability and change. In 1991, additional task of developing options for socio-economic response strategies related to climate variability and change was added to the programme.
The main thrusts of WCIRP include: (i) testing of methodologies for national climate impact and sea level rise assessment; (ii) providing coordination of national climate impact and response strategies programmes; (iii) improved techniques for making inventories of sources and sinks of greenhouse gases; (iv) developing techniques for national response strategies; (v) improving public information; and (vi) air quality assessment and air pollution mitigation strategies.
UNEP is responsible for the implementation of the WCIRP.
The progress made over the past 15 years and the knowledge generated through the WCP has been a solid basis for the work of the IPCC. The WCP has also stimulated national climate related activities and enhanced national efforts in climate research as well as establishment and implementation of National Climate Programmes. The manner in which the national climate programmes contribute to the WCP and how the WCP and its associated activities form the foundations of IPCC assessments which in turn provide the basis for the Framework Convention on Climate Change and its implementation is illustrated in Figure 1.
The existing organization and coordination arrangements of WCP and related international activities is shown in Figure 2. Each sub programme has an advisory committee. The representatives of those advisory committees, together with representatives of IPCC and the Interim Secretariat for UN/FCCC, form the Coordinating Committee for the WCP to provide the overall coordination to the Programme. The Executive Heads of the seven international organizations that are currently the main players in the WCP, as well as the senior representative of those organizations meet annually to ensure interagency coordination.
Figure 1. National climate activities: their relationship to national and international assessments and policies.
Figure 2. International climate activities: existing organizational and co-ordination arrangements.
Through its Atmosphere Programme, UNEP contributes to the international actions related to climate change by assisting monitoring, research and assessment activities that are basic to rational decision-making and response. The Atmosphere Programme consists of three basic elements:
1. risks to the ozone layer;
2. atmospheric pollution and its transport; and
3. climate variability and change.
Much of UNEP's activities in the field of climate change falls within the framework of the World Climate Impact Assessments and Response Strategies Programme (WCIRP). WCIRP is a programme that UNEP is responsible for implementing under the World Climate Programme (WCP) (see section 2 (c) above). The specific activities that are being implemented under the WCIRP include studies/projects on the issue of climate variability such as drought and floods and the preparedness for such events; initiating and supporting studies to assess the impacts of climate change and sea-level rise; and providing assistance in identifying response strategies to mitigate or adapt to climate variability and change. The Atmosphere Programme also encompasses a number of country study projects:
1. Sources and Sinks of Greenhouse Gases
UNEP is supporting the development and testing of an international standard methodology for developing national inventories of sources and sinks of greenhouse gases through a GEF funded project on "Country Case Studies on Sources and Sinks of Greenhouse Gases", under which OECD Environment Directorate and IPCC Working Group I Technical Support Unit have the primary responsibility for the development of methodology guidelines. Under the current phase of the project, direct technical support is provided to 11 developing countries to develop government-sanctioned greenhouse gas inventories in those countries. The Ninth Session of the Intergovernmental Negotiating Committee on the FCCC has recommended that the draft guidelines be used by the Parties to the Convention for the preparation of their national inventories. Revised guidelines will be presented to the First Session of the Conference of the Parties.
2. Methodologies for Assessing Climate Impacts and Adaptation Strategies
Common methodologies are required by the UN Framework Convention on Climate Change (UN/FCCC) for the formulation of national programmes containing measures to adapt to the adverse effects of climate change. UNEP in collaboration with the IPCC is responding to these needs through developing guidelines and methodologies for assessing impacts of climate change and development of adaptation strategies, and through testing them in country case studies. A project for carrying out these country studies has been submitted to the GEF for consideration for funding. A handbook on methods for assessing climate impacts and adaptation will also be prepared in cooperation with the IPCC and other relevant institutions.
3. Greenhouse Gases Abatement Costing Studies
Among the commitments under the UN/FCCC is the requirements for the provision of resources equivalent to the full, incremental costs to developing countries to address the issue of climate change. The issue of determining incremental costs has not been resolved partly because methodologies for costing abatement efforts have yet to be developed and agreed. UNEP initiated the project: "Preparation of a Methodology to Undertake National Greenhouse Gas Abatement Costing Studies" in 1991 to establish a common methodological framework for assessing the economic costs of limiting greenhouse gas emissions. This framework will form an input to the work of IPCC and feed into the FCCC process in relation to preparation of national communication of information on the implementation of the Convention. An important part of the project is the development and support of capabilities within developing countries for conducting such national abatement analysis. The UNEP Collaborating Centre on Energy and Environment (UCCEE) at RISO National Laboratory, Denmark, coordinates the project.
Information exchange and raising public awareness is another important activity under the Atmosphere Programme. In response to the need for information on climate related country activities, UNEP, together with the UN/FCCC Interim Secretariat developed a joint project on "Country Activities on Climate Change: Information Exchange System (CLIMEX)" to better serve the information needs of countries and international organizations involved in climate related work. Detailed information dissemination and public awareness work has been carried out by the Information Unit on Climate Change (IUCC) which was established in 1991 to provide timely, accurate, and action-oriented information on all aspects of climate change to policy-makers and opinion leaders. In carrying out this mandate, IUCC has helped to raise international awareness of this critical issue.
During the biennium, 1994 and 1995, the Atmosphere programme will concentrate on strengthening coordination of the climate impact and response strategy related activities rather then carrying out a research based programme. As a part of this effort, projects for establishing and operating regional and national Climate Impact and Response Strategy Networks are being planned and developed. The objectives of the Networks are to improve the coordination of climate impact and response strategy related activities both nationally and internationally, including coordination of the existing channels and mechanisms for exchange of information and to enable exchange of national experience among countries in order to identify and develop response strategies, as well as projects, to mitigate/adapt to climate change and its impacts. It is hoped that these efforts will lead to strengthening of regional and national capacity, particularly in the developing countries to deal with the subject of climate change and assist the countries in implementing the Framework Convention on Climate Change and the World Climate Programme.
Urban and transboundary air pollution are areas which will be strengthened under the Atmosphere Programme. Projects are currently under development for (i) assessment of the state of local air pollution; (ii) development of methodologies and guidelines for assessment of air pollution and its impacts; (iii) capacity building, technical support and training for the management of urban air-pollution; and (iv) special case studies of cities.
The other international activities that play an important part in influencing the world climate agenda can be categorized under four types of activities as follows:
Research and capacity building
During the 1980s The growing awareness of potential climate change problems led to increased research in relevant fields. The greenhouse effect and global warming issue is now relatively well-known and is one of the most serious and difficult challenges facing the world community today.
How does the climate system work?
The Earth absorbs radiation from the Sun, mainly at the surface. This energy is then redistributed by the atmosphere and ocean and re-radiated to space at longer ("thermal", "terrestrial" or "infrared") wave-lengths. Some of the thermal radiation is absorbed by radiatively-active ("greenhouse") gases in the atmosphere, principally water vapour, but also carbon dioxide, methane, the CFCs, ozone and other greenhouse gases. The absorbed energy is re-radiated in all directions, downwards as well as upwards such that the radiation that is eventually lost to space is from higher, colder levels in the atmosphere. The result is that the surface loses less heat to space than it would do in the absence of the greenhouse gases and consequently stays warmer than it would otherwise be. This phenomenon, which acts rather like a "blanket" around the Earth, is known as the greenhouse effect.
What factors can change climate?
Any factor which alters the radiation received from the Sun or lost to space, or which alters the redistribution of energy within the atmosphere, and between the atmosphere, land and ocean, will affect climate.
Findings of scientific research since 1990 do not affect the fundamental understanding of the science of the greenhouse effect and either confirm or do not justify alteration of the major conclusions of the first IPCC Scientific Assessment, in particular the following:
emissions resulting from human activities are substantially increasing the atmospheric concentrations of the greenhouse gases: carbon dioxide, methane, chlorofluorocarbons, and nitrous oxide;
the evidence from the modelling studies, from observations and the sensitivity analyses indicate that the sensitivity of global mean surface temperature to doubling CO2 is unlikely to lie outside the range 1.5o to 4.5oC;
Significant new findings and conclusions of the IPCC update on the key findings of its First Assessment are:
Gases and aerosols
Depletion of ozone in the lower stratosphere int he middle and high latitudes results in a decrease in radiative forcing which is believed to be comparable in magnitude to the radiative forcing contribution of chlorofluorocarbons (CFCs) (globally-averaged) over the last decade or so.
The cooling effect of aerosols (+) resulting from sulphur emissions may have offset a significant part of the greenhouse warming in the Northern Hemisphere (NH) during the past several decades. Although this phenomenon was recognized in the 1990 report, some progress has been made in quantifying its effect.
The Global Warming Potential (GWP) remains a useful concept but its practical utility for many gases depends on adequate quantification of the indirect effects as well as of the direct. It is now recognized that there is increased uncertainty in the calculation of GWPs, particularly in the indirect components and, whilst indirect GWPs are likely to be significant for some gases, the numerical estimates Of the IPCC are limited to direct GWPs only.
Whilst the rates of increase in the atmospheric concentrations of many greenhouse gases have continued to grow or remain steady, those of methane and some halogen compounds have slowed.
Some date indicate that global emissions of methane from rice paddies may amount to less than previously estimated.
The anomalously high global mean surface temperatures of the late 1980s have continued into 1990 and 1991, which are the warmest years in the record.
Average warming over parts of the Northern Hemisphere mid-latitude continents has been found to be largely characterized by increases in minimum (night-time) rather than maximum (daytime) temperatures.
Radiosonde data indicate that the lower troposphere has warmed over recent decades. Since meaningful trends cannot be assessed over periods as short as a decade, the widely reported disagreements between decadal trends of air temperature from satellite and surface data cannot be confirmed because the trends are statistically indistinguishable.
The volcanic eruption of Mount Pinatubo in 1991 is expected to lead to transitory stratospheric warming. With less certainty, because of other natural influences, surface and tropospheric cooling may occur during the next few years.
Average warming over the Northern Hemisphere during the last four decades has not been uniform, with marked seasonal and geographic variations; this warming has been especially slow, or absent, over the extratropical north-west Atlantic.
The consistency between observations of global temperature changes over the past century and model simulations of the warming due to greenhouse gases over the same period is improved if allowance is made for the increasing evidence of a cooling effect due to sulphate aerosols and to stratospheric ozone depletion.
The IPCC predicted that if no measures are taken to mitigate climate change, an average rise of temperature of 0.3 oC per decade would be experienced during the next century, and that such a rate would result in an increase of global mean temperature of 1 oC above the present value by the year 2025, and 3 oC increase by the end of the next century.
If the greenhouse gases continue to be emitted at current rate, the sea level is predicted to rise by 6 cm per decade, reaching a level of 65 cm rise in the sea level as compared to the present level, by the end of the next century.
A modest decrease of global mean temperature seems to have occurred during the last few years, probably due to the Pinatubo eruption in 1991 which resulted in emission of dust into the stratosphere, but the dust concentration in the stratosphere is now almost back to normal.
The steady increase in the CO2 concentration in the atmosphere had ceased since around 1992 but this trend seems to be coming to an end. This halt in the CO2 increase may have been associated with the El Nino event and possibly the Pinatubo eruption. There are no known processes that would maintain the halt.
Rapid (several decades to a century) natural changes of climate have recently been discovered on Greenland. However, the geographical scope of the observed changes are unknown, hence, the changes may not be global.
Previous findings of the IPCC showed that there is cooling effect on the atmosphere from anthropogenic sulphate aerosols in the troposphere and decreasing stratospheric concentration of the ozone in the stratosphere. However, the spatial distribution of the cooling effect and the greenhouse effect differ markedly and do not compensate each other.
Key issues that are being tackled by the IPCC under its Second Assessment include:
The future scenarios of greenhouse gas emissions depend heavily on the assumptions that are made for the derivation of the scenarios from macro-economic models. In the IPCC Second Assessment, emphasis will be placed on the interpretation of the scenarios of future emissions of greenhouse gases in terms of socio-economic factors, rather than presenting new scenarios.
Studying the various climate models to sensitivities to changing composition of the atmosphere. The studies should enable identification of which models are suitable for projections of climate change on a regional scale. This, in turn, should facilitate the regional and local studies of impacts which are based on the projected climate change.
IPCC will also attempt to provide a better scientific basis for the interpretation of the objective (Article 2) of the FCCC. However, the ultimate decision on what is considered as "dangerous anthropogenic interference with the climate system" lies with the Parties to the Convention.
A more thorough analyses of how serious the impacts of climate change might be, on the environment and on various sectors of economy such as agriculture, forestry, water resources and fisheries. In connection with this issue, experiments are being carried out with more advanced climate models so that better assessments can be made on the regional climate change and its impacts. However, some aspects of the magnitude and distribution of regional climate change and its impacts will remain unpredictable because of the natural climate variability and the occurrence of extreme weather events.
Refinement of the knowledge on Global Warming Potential of greenhouse gases.
The signing of the FCCC and the adoption of Agenda 21 at UNCED in Rio de Janeiro marked a new turning point and provided a new focus in the climate agenda for international organizations and the nations of the world.
While experts continue their efforts to increase the scientific knowledge and confidence on the complex issue of climate change, there are several options of no-regret response strategies that Governments and industries can begin to implement and are being implemented, for example, energy conservation strategies, planting of trees to increase carbon dioxide sinks, increasing the efficiency of the transport systems, and development and utilization of clean energy. UNEP has been advocating a precautionary approach in dealing with scientific uncertainties. It will continue to catalyze and initiate studies on the impacts of climate change and encourage and assist decision makers to identify and implement no-regret response strategies to mitigate and adapt to climate change and variability so that society can continue to develop in a sustainable manner with full consideration of the needs of future generations that will inhabit this earth.
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