Effects of increased UV-B radiation The UNEP Report entitled “Environmental

Ef-fects of Ozone Depletion” (UNEP, 1994b) deals in detail with the possible effects of increased UV-B ra-diation resulting from the depletion of stratospheric ozone. The report points out that, particularly with respect to the effect of UV-B radiation on human health, food production and natural ecosystems, the-re athe-re still major uncertainties and a substantial need for research, since research in this area obtains very little support internationally.

A major cause for concern arising from the effect of increased UV-B radiation in combination with stratospheric ozone depletion involves the increased incidence of skin cancer. Epidemiological studies conducted worldwide provide conclusive evidence that increased epithelial skin cancer (basaliomae, epitheliomae) in fair-skinned populations correlates to exposure to the sun and that inhabitants of coun-tries near the Equator are disproportionately af-fected. This increased incidence of skin cancer has been attributed primarily to changed leisure habits (sunbathing) (Schaart et al., 1993). The specific role played by UV-B radiation in the development of

ma-0 20 40 60 80 100

Ozone concentration (µg O3 m-3)

Year

1980

1860 1880 1900 1920 1940 1960

Vienna

Montsouris (Paris)

Arkona

Friedrichs-hafen

Davos

Arosa

Hohen-peißenberg Hohenpeißenberg Figure 28

Current and historical measurement series for surface ozone at various locations in Central Europe since 1850.

Sources: Volz and Klug, 1988; Claude and Köhler, 1994

lignant skin tumors has not been fully explained as yet, although there are a number of indications that UV-B radiation is indeed a causal factor (Schaart et al., 1993; Setlow et al., 1993). Other studies have con-cluded that the entire spectrum of solar radiation at the surface causes skin cancer (e.g. Wolf et al., 1994).

In the light of these findings, research into the rela-tionship between leisure-related and work-related exposure to UV-B radiation and the development of skin cancer on the long run must be greatly intensi-fied. Patients with sensitive skin must be warned against prolonged exposure to direct solar radiation without adequate skin protection.

2.3.2

Recent Measurements

In the first two years following the eruption of Pin-atubo in June 1991, the intensity of UV-B radiation, the rays which sunburn, was higher than in previous years on account of the very low ozone concentra-tions over Germany (the minimum level of which was reached in spring 1993) (Vandersee, 1994). Meas-uring UV-B radiation involves a number of technical problems. Measurements obtained in the past must therefore be treated with a degree of scepticism, sin-ce in most cases they are not comparable with those obtained today. An increase in tropospheric ozone, for example, can induce a decrease in UV-B radiation at the surface, even if the total-column ozone level in the atmosphere is declining (Brühl and Crutzen, 1989). The 5% per decade increase in tropospheric ozone now observed in some regions of the northern hemisphere may have partially compensated (by 2%

per decade) for the increase in UV-B radiation (Madronich, 1992). Clouds also play a critical role with respect to the radiative balance. A study carried out by Mims (1994) concludes that, as a result of the backscattering of solar radiation by cumulus clouds, the level of UV-B radiation on a cloudy day may be more than 25% greater than on a cloudless day.

2.4

Recommendations for Research

• Continuation of the national ozone research gram, in cooperation with other international pro-grams. In particular, support for research aimed at gaining an understanding the natural variability of the ozone layer, without which it is impossible to predict the development of the ozone layer over the next 50 years, as well as research into the chemistry of the heterogeneous processes, essen-tial for assessing the impact of substitutes for

CFCs.

• Air traffic: investigation of the impact of rising air traffic levels on the ozone content of the upper tro-posphere and the lower stratosphere is already a component of various research foci. Given the complexity of the problem, this work must be in-tensified and consolidated over the long term.

• Intensification of research into the inter-relation-ships between air pollution and the production and diffusion of tropospheric ozone, especially near-surface ozone.

• Support for the International Tropospheric Ozone Year (ITOY): despite the fact that tropospheric ozone plays a crucial role in the overall context of global change as an air pollutant and as an indirect greenhouse gas, there are considerable gaps in our knowledge of its global distribution and variabil-ity. Any statements on trends are mainly limited to the mid-latitudes of the northern hemisphere, de-spite the fact that the tropics and subtropics are also affected by any increase in tropospheric ozo-ne.

• Research into the impact of air pollution and UV-B radiation on the biosphere, i.e. on the health of hu-mans, on plant production and on natural ecosys-tems. In particular, there is a lack of investigations into the long-term effect of such stresses and their socioeconomic impacts.

• Coordination between stations measuring UV-B radiation and those measuring ozone levels. The new UV-B radiation measurement stations should cooperate closely or be integrated at both national and international level.

• Substitutes and the respective new technologies:

further development of substitutes for CFCs and HCFCs, including new technologies for their appli-cation, are urgently needed. The search for tech-nologies that do not require fluorocarbons must be forced ahead in those areas not yet covered.

This must also include appropriate funding for the relevant research.

2.5

Recommended Action

Stratospheric Ozone

The WBGU welcomes the Third Report by the Federal Government on Measures to Protect the Ozone Layer (Deutscher Bundestag, 1994). It ac-knowledges the wide-ranging support for the devel-opment of substitutes to replace CFCs and assumes that further progress can be made in this field. In the same manner, the Council welcomes the efforts made by the Federal Government to provide adequate fi-nancial support for the Multilateral Fund of the

135 Recommended Action C 2.5

Montreal Protocol, creating a framework for sup-porting selected partner countries. Measures for Chi-na and India, the two largest consumers of CFCs in this group, could prove especially effective. In the face of the continued threat posed until the middle of the next century by the damage to the stratospheric ozone layer (the so-called “ozone hole”), it is essen-tial that everything be done to achieve the rapid end to the production and consumption of CFCs and HCF-Cs in all countries, including the developing and new-ly industrializing nations.

In addition, the leakage of halons and CFCs from existing appliances must be prevented at all costs.

This means intensifying the recycling program, which in turn involves even greater endeavors to raise pub-lic awareness of the problem in question.

The WBGU recommends that the proposals made in the latest UNEP report on the state of the ozone layer be taken up and that appropriate measures be put into effect. The UNEP report recommends world governments to phase out the consumption of par-tially halogenated substitutes (HCFCs) by as early as the year 2004 in order to accelerate the healing pro-cess in the stratospheric ozone layer.

Tropospheric Ozone

Changes in emission levels must be brought about through the determined implementation of measures to reduce the energy-related and non-energy related release of precursor substances causing increased ozone production (SRU, 1994).

UV-B Radiation

In view of the increased incidence of skin cancer, work on informing the public about the definite asso-ciation between UV-B exposure and the long-term development of malignant skin tumors must be in-tensified substantially.

3.1

Preliminary Remarks

The United Nations Convention on the Law of the Sea (UNCLOS), to which Germany acceded on Oc-tober 14, 1994, followed by numerous other industri-alized countries, entered into effect on November 16, 1994. This convention, which according to the Ger-man government represents the “most important le-gal instrument of the United Nations to date”, was negotiated at the UN Conference on the Law of the Sea from 1973 to 1982 to provide a comprehensive regime for all types of use of the seas and, at the same time, an international “constitution” for all marine regions. November 16, 1994 thus also represents a turning point in marine environment protection, one of the focal points of global environmental policy.

Even though the success of UNCLOS cannot be jud-ged upon in this short period of time and although some of its rules are already part of international cus-tomary law or are still unclear and inadequate, a ma-jor step has been taken towards sustainable manage-ment of the seas, as has been called for in the 1987 re-port of the International Commission for Environ-ment and DevelopEnviron-ment.

In the following the effects of UNCLOS on the protection of marine ecosystems will be analysed and the needs for further reform discussed.

3.2

Utilisation Functions of the Seas

In its 1994 annual report the Council depicted the global threat to soils based on their functions (soil functions) (WBGU, 1994). A distinction was made here between habitat function, regulation function, utilisation function and cultural function. Such a mul-ti-functional model (marine functions) could also be applied to the threat to the seas. In this section, how-ever, the Council limits itself to an analysis of the hig-hly complex utilisation functions of the seas, which

represent the main focal point of the Convention on the Law of the Sea.

Three types of utilisation functions constitute the primary problem area covered by marine environ-ment policy:

– environmental damage through the transport function of the seas,

– impairment of the disposal function of the seas through terrestrial sources of emissions and the dumping of various substances (Fig. 29),

– damage to the resource function of the seas, partic-ularly through overexploitation of living re-sources.

3.3

Transport Function

3.3.1

Marine Pollution from Vessels

The classic example of marine pollution in public perception is pollution through maritime transport.

Even though tanker accidents still occur and can cau-se environmental disasters, the greatest success up to now has been achieved in this particular area of ma-rine environment policy (Fig. 29). UNCLOS requires in Art. 211 (2) the Parties to enact laws and regula-tions applying to ships flying their flag which must be no less effective than the existing international agreements on the protection of the environment (-UNCLOS commentary).

These international agreements date back to the 50s when numerous shipping nations agreed to the 1954 London Convention for the Prevention of Pollu-tion of the Sea by Oil (OILPOL). At that time this agreement was considered to be exemplary since it was the first legally binding instrument with univer-sal regulatory application for the protection of an en-vironmental medium against pollution. To this ex-tent, marine environment policy could be regarded as a pacemaker for global environmental policy – and,