|Environmental Change and International Law: New Challenges and Dimensions (UNU, 1992, 493 pages)|
|Issues in international environmental law|
|4. Emerging principles and rules for the prevention and mitigation of environmental harm|
Because of underlying scientific uncertainty regarding the problems of global environmental change, and because there is an urgency to take anticipatory actions to prevent or abate a future environmental harm or risk, it becomes imperative for the Contracting Parties to take all possible preventative actions. To wait for the threat to become an actual problem would be to wait until it is too late.11
One treaty-making device commonly used to cope with this situation is called a "double-track" approach. This approach utilizes a framework convention and annexes and/or protocols. The framework convention sets out the general obligations of the Contracting Parties; annexes and protocols are then formulated to the general obligations set by the framework convention. New multilateral treaties on global environmental change follow this approach.
The 1985 Vienna Convention for the Protection of the Ozone Layer provides in Article 2 that:
The Contracting Parties are, in accordance with the means at their disposal and their capabilities, under obligations to:
(a) cooperate by means of systematic observations, research and information exchange in order to better understand and assess the effects of human activities on the ozone layer and human health and the environment from modification of the ozone layer;
(b) adopt appropriate legislative or administrative measures and cooperate in harmonizing appropriate policies to control, limit, reduce or prevent human activities under their jurisdiction or control should it be found that these activities have or are likely to have adverse effects resulting from modification or likely modification of the ozone layer;
(c) cooperate in the formulation of agreed measures, procedures and standards for the implementation of this Convention, with a view to the adoption of protocols and annexes;
(d) cooperate with competent international bodies to implement effectively this Convention and protocols to which they are party.
Scientific knowledge on the physical and chemical processes that may modify the ozone layer and affect human health and other biological systems were not evident during the adoption of the Vienna Convention. The Contracting Parties therefore agreed to cooperate under the general terms as stated supra. In contrast, the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer set out concrete control measures by which the Parties agreed to reduce the calculated amount of consumption of the controlled substances.
Another example is the 1979 ECE Convention on Long-Range Transfrontier Air Pollution. In Articles 2-5, the Contracting Parties agreed in general terms to protect humans and their environment and to cooperate in information exchange, consultation, research, and monitoring. Article 9 in particular stresses the need for the implementation of the existing "Cooperative Programme for the Monitoring and Evaluation of the Long-Range Transmission of Air Pollutants in Europe" (EMEP). In 1984, the Protocol was adopted for the long-term financing of EMEP. And in 1985 and 1989, protocols were adopted respectively for the reduction of sulphur emissions or their transboundary fluxes by at least 30 per cent, and for the control of emissions of nitrogen oxides or their transboundary fluxes. Many support the argument that the Vienna Convention and the Montreal Protocol are a paradigm for international cooperation to challenge global climate change.12