6.11.1. Stabilising Greenhouse Gas Concentrations

Table 6.9 illustrates the reductions in emissions of the most important greenhouse gases that would be required now to stabilise atmospheric concentrations at present day levels (IPCC, 1990a).

Table 6.9. Reductions in greenhouse gas emissions required to stabilise atmospheric concentrations

The Montreal Protocol and subsequent amendments have already significantly reduced many of the halocarbon species, particularly the CFCs, by at least 90% in developed nations, to halt the destruction of stratospheric ozone. Paradoxically, as the ozone layer slowly repairs itself, its greenhouse forcing will increase.

Far more importantly, however, are the other greenhouse gases, most noticeably carbon dioxide, the major greenhouse gas that is increasing anthropogenically, and the by-product of the world’s energy production. Clearly, a 60% cut in carbon dioxide emissions, either now or over the next few years, would be almost impossible to achieve. Even the most optimistic IPCC emissions scenario (IS92c) projects a rise in carbon emissions by 2025, with only a gradual decline by the year 2100. In view of this, it is worth examining what action is being taken by the global community to safeguard against the impacts of anthropogenic climate change.