1.2 Ultimate objective of the UNFCCC

The UNFCCC was adopted in May 1992 in New York and opened for signature at the ‘Rio Earth Summit’ in Rio de Janeiro a month later. It entered into force in March 1994 and has achieved near universal ratification with ratification by 189 countries of the 194 UN member states (December 2006)^[2].

1.2.1 Article 2 of the Convention

Article 2 of the UNFCCC specifies the ultimate objective of the Convention and states:

‘The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner’ (UN, 1992).

The criterion that relates to enabling economic development to proceed in a sustainable manner is a double-edged sword. Projected anthropogenic climate change appears likely to adversely affect sustainable development, with adverse effects tending to increase with higher levels of climate change and GHG concentrations (IPCC, 2007b, SPM and Chapter 19). Conversely, costly mitigation measures could have adverse effects on economic development. This dilemma facing policymakers results in (a varying degree of) tension that is manifested in the debate over the scale of the interventions and the balance to be adopted between climate policy (mitigation and adaptation) and economic development.

The assessment of impacts, vulnerability and adaptation potentials is likely to be important for determinating the levels and rates of climate change which would result in ecosystems, food production or economic development being threatened to a level sufficient to be defined as dangerous. Vulnerabilities to anthropogenic climate change are strongly regionally differentiated, with often those in the weakest economic and political position being the most susceptible to damages (IPCC, 2007b, Chapter 19, Tables 19.1 and 19.3.3).

Limits to climate change or other changes to the climate system that are deemed necessary to prevent dangerous anthropogenic interference with the climate system can be defined in terms of various – and often quite different – criteria, such as concentration stabilization at a certain level, global mean temperature or sea level rise or levels of ocean acidification. Whichever limit is chosen, its implementation would require the development of consistent emission pathways and levels of mitigation (Chapter 3).