The goal for COP1 was therefore set at adoption of legally binding obligations to reduce greenhouse gas emissions. It was expected that 15 years down the line, the larger, newly industrializing countries would together be among the largest emitters of greenhouse gas emissions.
Article 3 of the UNFCCC states: "The Parties should protect the climate system for the benefit of present and future generations of humankind, on the basis of equity and in accordance with their common but differentiated responsibilities and respective capabilities. Accordingly, the developed country Parties should take the lead in combating climate change and the adverse effect thereof."
The phrase "common but differentiated responsibilities" has become a key element in international climate negotiations. The debate centred on whether developing countries would be bound to commit reductions in GHG emissions, in addition to developed countries.
Developing countries refused to take up binding commitments, declaring that: historical responsibility for climate change rested with the developed countries, listed as Annex 1 countries in the UNFCCC;
given their limited resources and lower responsibility for GHG emissions, their priority lay in development and eradication of poverty; and they had lesser financial abilities to pay for reductions.
Non-Annex I countries were finally exempted from additional binding obligations under the Berlin Mandate.
The parties decided to initiate negotiations for what later came to be known as the Kyoto Protocol.
At Berlin, Parties agreed to develop a "comprehensive menu of actions" over a two year Analytical and Assessment Phase (AAP), to enable countries to pick future options that made the best economic and environmental sense for each of them to address the original goal of the convention - to stabilize GHG emissions by Annex 1 countries at 1990 levels by 2000.
The US then pressed hard with the idea of 'Joint Implementation' (JI) to reach this goal. It was Norway that first proposed 'JI' at such an early stage in the UNFCCC process. (This is different from the JI as well as CDM - Clean Development Mechanism - as it is known today).
Hence forward, negotiations focused on methods by which countries around the world reduce GHG emissions, not necessarily by reducing their own emissions, but also by 'helping' other countries to reduce theirs!
These were the harbingers of what would develop into emissions trading from which the CDM would later emerge.
The above is only an abstract of "COP-1, Berlin Mandate". The complete and original 'Berlin Mandate' is available for your reference here.
Further reading
Framework Convention on Climate Change