The atmospheric concentrations of carbon dioxide (CO2) and other greenhouse gases have been rising steadily in recent years. The rise in the level of CO2 is largely derived from the combustion of fossil fuel. If the level of these gases continue to increase at the present rate, the CO2-equivalent concentration of all the greenhouse gases will be doubled in 2025-50 compared to the pre-industrial level, and global mean temperature will rise by 2-3℃. This is called global warming.
Such a temperature rose will have various significant effects upon the global environment. The rise in sea level is predicted to be around 30-50 cm, and this will threaten the coastal zones of many countries, in particular those consisting of small islands. The increase in average precipitation, the decrease in soil moisture over northern mid-latitude continents in summer, and some disordered changes in regional ecosystems are also predicted to be widely observed around the world. Above all, droughts in the granary regions of North America and Southern Europe may probably reduce agricultural production by nearly 30% and cause a worldwide food crisis.
On the other hand, the global mean temperature has already been confirmed to have risen actually by around 0.5℃ during the past 100 years. This rise is roughly in accord with the rise estimated from the increased concentrations of greenhouse gases, thus suggesting that it is caused by their greenhouse effects. Such an actuality of the warming is also evidenced by the retreat of glaciers, the rise in sea level, and the bleaching of coral reefs derived from elevated seawater temperature. Moreover, typhoons, cyclones, severe floods, droughts and forest fires which appeared through the world frequently in the 1990's may be symptoms of global warming at an accelerated speed.
Thus, scientific findings on global warming have now been fully reviewed and
there is wide understanding of the urgent character of the issue. However, to my
regret, international countermeasures necessary for prevention of global warming
have not yet been taken effectively. In particular, the Framework Convention on
Climate Change concluded in 1992 merely calls for an effort to return the
emissions of CO2 in developed
nations to the earlier (probably 1990) level by the end of the 1990's. It will therefore be nearly impossible to prevent global warming by such ambiguous and non-restrictive arrangement.
It should be emphasized that the stabilization (to remain unincreased) of the atmospheric concentration of CO2 is above all needed for prevention of global warming. The report by IPCC (1990) points out that the human-made emissions of CO2 must be reduced by more than 60% in order to stabilize its atmospheric concentration at the present level. It will however be difficult to carry out such a reduction extensively at a stroke. Hence many NGOs in the world have hitherto proposed a feasible target to reduce the emissions of CO2 in developed nations first of all by least 20% from the 1990 level by the year 2005.
The Alliance of Small Island States (AOSIS) submitted also a protocol draft including similar targets to the United Nations in 1994. Regretfully, the draft was not concluded at the First Conference of the Parties to the Convention (COP1) held in 1995. However, in response to public opinion desiring for prevention of the warming, a mandate was established at the COP1 which gave a definite promise to conclude some protocol for reducing the emissions of CO2 at the Third Conference (COP3) to be held (possibly in Japan) in 1997. Therefore, the COP3 will be exactly a crucial stage, and the task to conclude a protocol based on the draft prepared by AOSIS at this conference will be a touchstone to try if mankind can take a key step towards setting the issue of global warming in the 21st century.