The atmosphere:
global commons to protect
G. O. P. OBASI
describes the risks from climate change and ozone
depletion, and how the World Meteorological Organization (WMO) addresses
the protection of the atmosphere
The Earth's climate is controlled by complex and highly
interactive processes involving the atmosphere, land, the hydrosphere
(water in oceans, seas, lakes, rivers, etc.) and the cryosphere (ice
sheets, glaciers, snow), together with complex terrestrial and aquatic
biological processes. Most of the energy driving the global climate system
is radiation from the sun. Only about a quarter of the solar radiation
received at a level outside the atmosphere reaches the surface of the
Earth. A substantial part of the incoming solar radiation is depleted
through scattering, reflection and absorption by atmospheric constituents
which consist of atmospheric gases, water vapour and suspended aerosols.
To balance the incoming solar radiation, thermal/infrared (long-wave)
radiation is emitted by the Earth's surface back into space. The bulk of
this infrared radiation is intercepted and absorbed by the atmosphere.
This 'natural greenhouse effect' makes the Earth warmer than it would
otherwise be without the trapping of outgoing long-wave radiation by the
natural atmospheric blanket.
Ninety-nine per cent of the dry atmosphere is composed of nitrogen and
oxygen, two gases which do not absorb infrared radiation. It is
atmospheric carbon dioxide (CO2), water vapour and other minor greenhouse
gases which are involved in the natural trapping of the infrared radiation
leaving the Earth's surface.
Since pre-industrial times, atmospheric concentrations of many of the
greenhouse gases have increased tremendously. These include the CFCs and
the halons, both of which can also destroy the natural balance of
stratospheric ozone. Stratospheric ozone absorbs part of the sun's
radiation within wavelengths which are harmful to life on Earth. Current
global concentrations of stratospheric ozone are 10 per cent lower than
they were 25 years ago.
One of the most important greenhouse gases is CO2, whose concentration in
the atmosphere has increased from 280 parts per million by volume (ppmv)
to 358ppmv in 1994, giving a general increase of over 27 per cent since
pre-industrial times. This increase has been attributed largely to fossil
fuel combustion.
Significant increases have also been observed in atmospheric
concentrations of the other greenhouse gases, including methane, nitrous
oxide and global tropospheric ozone. Concentrations of methane and nitrous
oxide have, for example, grown by 145 per cent and 15 per cent
respectively since pre-industrial times. Such increases have been linked
to the rapid world population growth, which has resulted in increasing
demands for energy, food, water, shelter and other basic needs. Computer
models indicate that the continued accumulation of greenhouse gases in the
atmosphere could result in global climate change and global warming.
As some uncertainties still exist in the model predictions, it may take a
few more years to uniquely separate human-induced climate change signals
from natural climate variability in global climate trends.
Environmental Impacts
The 1995 second Assessment Report of the Intergovernmental Panel on
Climate Change (IPCC), established by WMO and UNEP, has for the first time
adopted a general consensus on the discernible human influence on global
climate. Although the actual magnitude of the potential warming due to
greenhouse gases is still subject to some debate, climate models based on
doubled CO2 and aerosols have projected an increase of between 1°C
and 3.5°C by the end of the next century. Observations from
instrumental records have indicated a general increase in the mean global
temperature of between 0.3°C and 0.6°C since the late 19th
century. This warming has not been geographically uniform and some regions
have cooled.
The predicted global warming would cause an expansion of ocean waters and
some melting of glaciers and ice caps which would result in sea level
rise. Recent climate models, which have included aerosol effects, have
projected a mean sea level rise of about 50cm with an uncertainty range of
20-85cm.
Changes in the global climate would also be associated with changes in
rainfall patterns and the space-time distribution of most of the climatic
parameters. The frequency, intensity, timing, rate of change, geographical
distribution and other characteristics of extreme climate events like
droughts, floods, severe storms, heat/cold waves would also change.
Climate change will also be associated with the concentration and
expansion of the world's major climatic zones including arid, semi-arid,
sub-humid and humid climates.
Any change in the global climate would have far reaching environmental,
biological, economic and social consequences due to the close linkages
between climate and global ecosystems, environmental degradation processes
including desertification, and the space-time distribution of natural
resources.
Most of the world's population is settled in coastal areas. Sea level rise
would therefore threaten life, property and productive land in low-lying
islands and coastal zones. With a 50cm sea level rise, about 92 million
people would be threatened and much productive land would be lost. Sea
level rise will also cause the destruction of urban areas, contamination
of water supplies, changes in coastlines and migration of people from
affected areas - environmental refugees. And some coastal areas and small
low-lying islands could be rendered uninhabitable.
Numerous studies suggest that the composition and geographical
distribution of many ecosystems will shift as individual species respond
to climate change. The shifts in the major climatic zones will also have
significant impacts on agricultural systems. Decline in agricultural
production is expected in those highly vulnerable areas which are least
able to adjust to climate change. Existing forest zones and range lands
would also be affected by the changes in the patterns of rainfall,
temperature and other climatic parameters. These could influence changes
not only in their composition, function and biological productivity, but
also shift the boundaries between the forests, grasslands and shrublands -
promoting desertification processes. And some species may be lost as a
result of climate stress leading to a reduction in global biodiversity.
Climate change is also likely to have adverse direct and indirect effects
on human health, due to changes in the pattern of climatic stress,
including those generated by extreme climate events, vector-borne and
viral diseases.
The quality and quantity of fresh water from precipitation, rivers, lakes,
underground resources and others will also be affected by climate change
through changes in the space-time patterns of the hydrological cycle. Any
water stress induced by climate change will have serious socio-economic
impacts, due to the continuous increase in the demand for water by the
rapidly increasing world population.
A significant decrease has been detected in stratospheric ozone, which
protects life on our planet from dangerous ultraviolet radiation from the
sun - ultraviolet radiation has been linked to skin cancer and many other
harmful effects on terrestrial and marine ecosystems. The decrease and the
corresponding 'ozone hole' have been associated with CFCs and halons
injected into the atmosphere by human activities. The depletion of
stratospheric ozone will continue until the concentration of substances
depleting it have diminished to a 'pre-ozone hole' value of 2ppbv. This is
expected to be achieved by the end of the 21st century if the current
measures to reduce the emissions of ozone-depleting substances are
maintained.
Response
The global concern and awareness of the environmental, biological and
socio-economic disasters which could be associated with climate change and
ozone depletion led, in 1988, to the establishment of the WMO/UNEP IPCC
and to the three conventions which emanated from the United Nations
Conference on Environment and Development (UNCED) in 1992, namely the
United Nations Framework Convention on Climate Change (UN/FCCC), the
International Convention to Combat Desertification (INCD) and the
Convention on Biological Diversity. These provide action plans and
measures which will greatly contribute to the protection of the
environment and the sustainable utilization of natural resources. UNCED
resulted in Agenda 21, a blueprint for action on the environment and
sustainable development.
Periodic scientific assessments of ozone which have been undertaken by WMO
and UNEP provided the basis for negotiations which resulted in the
Convention for the Protection of the Ozone Layer (Vienna 1985) and its
Montreal Protocol (1987). Amendments to the Protocol (London 1990;
Copenhagen 1992; Vienna 1995) require drastic cuts in the use of CFCs,
halons and other ozone-depleting substances.
Within its mandate WMO contributes actively to the protection of the
atmosphere through major programmes which include the World Weather Watch,
the World Climate Programme, the Atmospheric Research and Environment
Programme and the Hydrology and Water Resources Programme. WMO has the
responsibility of providing authoritative scientific information and
advice on the state and behaviour of the Earth's atmosphere, the climate
it generates and the assessment, management and distribution of freshwater
resources.
Monitoring the atmosphere
WMO ensures the continuous monitoring of all components of the climate
system. The corresponding data and information, which are exchanged
internationally through the WMO Global Telecommunication System on a
real-time basis, are derived from:
- some 9,000 observing stations on land;
- 7,000 voluntary observing ships;
- 350 automated or partially automated land-based weather stations;
- 300 moored buoys or fixed platforms and 600 drifting buoys;
- commercial aircraft.
Sea-level gauges have also been installed in many coastal areas for
monitoring sea-level changes. A number of geostationary and polar orbiting
meteorological satellites, coordinated by WMO, as well as environmental
satellites provide continuous observation of the Earth's atmosphere,
oceans and land surface.
Through the WMO Global Atmosphere Watch (GAW), about 350 stations monitor
the chemical composition of the atmosphere, including greenhouse gases,
the regional distribution of sulphur and nitrogen compounds, aerosols and,
in a few locations, toxic metals. This network contributes to WMO's Global
Ozone Observing System which has continuously monitored ozone patterns
since the 1950s.
Application, research and
capacity-building
Along with the systematic monitoring of all components of the global
climate system, WMO places strong emphasis on the application of
environmental data to socio-economic activities. These data are used by
National Meteorological and Hydrological Services, a number of WMO
Regional and World Meteorological Centres, strategically located over the
globe, which use powerful computers and sophisticated numerical models to
provide elaborate weather/climate information including short, medium and
long-term forecasts. These weather/climate information and prediction
services are used in the planning and management of many socio-economic
activities such as agriculture and forest management, water resource
management, transport, mitigation of natural disasters, pollution control,
protection of the ozone layer and coastal zone management. The atmosphere
is one of the most important resources available for humankind and
therefore must be adequately protected.
Over the years, WMO has also encouraged research into all aspects of the
climate system on the basis of the data collected from all parts of the
globe. All WMO programmes contribute to this global effort. It is through
such a long period of data collection, analysis, archival and systematic
research that WMO alerted the world community to the increasing
accumulation of greenhouse gases and their potential impact on the global
climate, the existence of the 'ozone hole' and the associated risk to life
from the penetrating ultraviolet radiation, the hazards of acid rain, the
increase in pollutants and their transboundary transport. Furthermore, the
substantive findings of the IPCC could not have been made without the
accurate, painstakingly acquired data. It is through some of WMO's
research projects that some new understanding of the natural processes
which drive the climate of our planet has emerged. Such efforts have also
improved the skill of climate information and prediction services for
multidisciplinary uses. Recent studies from the WMO Tropical Ocean and
Global Atmosphere project (TOGA) have also extended the predictability
range of climate in some regions and seasons to seasonal and interannual
time scales based on El-Niño and the associated Southern
Oscillation (ENSO) characteristics. Such forecasts are currently being
used successfully in the mitigation of the severe impact of droughts,
floods and other extreme events which are associated with ENSO.
As a follow up to the successful TOGA project, a new project has been
launched to tackle questions related to climate variability and
predictability on the global climate on time scales ranging from months to
a century. The project, CLIVAR, is also designed to increase our
understanding of the interactions of natural climate variability and its
modifications by human activities.
WMO has also been active in capacity-building through its Education and
Training and its Technical Cooperation Programmes. Over 20 WMO Regional
Meteorological Training Centres and a number of national training centres
contribute to the education and training of atmospheric scientists and
hydrologists. WMO also pursues a vigorous programme of capacity-building
in developing countries through the provision of experts and equipment. In
a year, over 500 people are on WMO fellowships. All of these measures
contribute to the enhancement of national, regional and global capacity to
develop appropriate policies for the protection of the atmosphere.
Some recent initiatives
As a response to UNCED and UN/FCCC, WMO together with the other
international organizations developed the Climate Agenda, an inter-agency
initiative which provides an international framework for the promotion of
climate-related activities, including research and applications to meet
the needs of society. The Climate Agenda provides an integrated framework
within which governments, international organizations and non-governmental
organizations can plan their own contribution to national and
international climate-related programmes according to their priorities.
Another recent initiative is the development of the Climate Information
and Prediction Services (CLIPS). The project was endorsed by the 12th WMO
Congress in June 1995. The major objective of CLIPS is to provide the
international framework necessary for comprehensive multidisciplinary
applications of climate information and prediction services in
environmental management and sustainable development. It aims to minimize
socio-economic calamities which are common, particularly in developing
countries. The Climate Agenda and CLIPS projects will therefore enable
governments to take timely and appropriate decisions which would support
national sustainable development efforts and the protection of the
environment.
Recognizing the gaps in the data needed to better understand climate and
climate change, and to reduce uncertainties in climate prediction, WMO,
jointly with other international organizations, established the Global
Climate Observing System (GCOS). GCOS is addressing issues related to the
observation of ocean climate, cloud radiation, the land surface and the
hydrological cycle. WMO is also considering management issues to improve
the quality, accessibility and exchange of data. Furthermore, WMO is a
co-sponsor of the Global Ocean Observing System (GOOS) and the Global
Terrestrial Observing System (GTOS).
These WMO activities are crucial for the efficient and effective
monitoring of the implementation of international agreements related to
climate change and the protection of the ozone layer.
National Meteorological and Hydrological
Services
The initiatives launched by the world community to address the climate
change and ozone issues require the maintenance and strengthening of
integrated monitoring systems together with research into all the
components of the global climate system. With the support of WMO,
important contributions are being made by national Meteorological and
Hydrological Services in providing data and services related to climate,
weather, water and atmospheric composition, including ozone.
What should be done
The 50th anniversary of the United Nations offered an opportunity to
highlight the achievements in the mitigation of environmental hazards and
the protection of the atmosphere through international collaboration.
While these achievements demonstrate the spirit of cooperation among
nations to ensure sustainable development, there are still several crucial
issues which should be addressed.
First, urgent measures should be taken to implement the relevant
international conventions and agreements, such as UN/FCCC, INCD and the
Convention on Biological Diversity.
Secondly, as regards the protection of the atmosphere from industrial and
other pollution, the principle of common but differentiated
responsibilities among developed and developing countries should apply.
Since the industrialized countries are the major producers of greenhouse
gases, and in view of their favourable economic, financial and technical
capabilities, they should lead the way in addressing the challenges posed
by climate change and other relevant issues. They are already taking the
lead in the case of ozone-layer depletion.
Thirdly, special consideration should be given to assist developing
nations, small island states and those with economies in transition with
human resource development and the transfer of environmentally sound
technologies such as energy efficiency, renewable energy production and
improved land-use management. Guaranteed financial support should also be
given to implement the international agreements as foreseen in UN/FCCC and
in INCD.
Lastly, there is a need to reinforce the monitoring, information exchange,
research, policy formulation and institutional capabilities of national
Meteorological and Hydrological Services, especially those of developing
countries. Increased support is required for the Climate Agenda, CLIPS,
the World Climate Programme, GAW, GCOS and other WMO programmes. This
support will ensure that the implementation of any policies and action
plans to protect the atmosphere, mitigate and/or adapt to climate change
will be based on rational scientific knowledge.
There is now a need to sound the warning that we have gone beyond the
point where the sustainable use of the atmosphere as a highly mobile dump
for man's waste is possible without serious consequences. We are now more
aware of the possible implications of depleting the stratospheric ozone
layer, the looming major change in climate and the concomitant projected
sea level rise. Furthermore, we are more conscious that failure to protect
the environment can lead to the degradation of the natural resource base
necessary for continuing and sustainable development. In spite of the
major initiatives and achievements that have been made in the past few
years, much still remains to be done if we are to achieve the targets of
Agenda 21 for the protection of the Earth's atmosphere for the benefit of
present and future generations of humankind.
The threats have been assessed; the responsibility recognized; the spirit
of cooperation and goodwill is evident. What is needed now is further
action.
Professor G. O. P. Obasi is the Secretary-General of the World
Meteorological Organization.
