Currently the Kyoto protocol imposes quantified emission limitation targets, affecting only industrialised countries (which are required to cut releases by 5% between 1990 and 2008-12). All sides agree that, even if this target is met, it will not prevent global emissions rising to 2010 and beyond. Talks on expanded commitments post-2012, possibly including more countries, are due to start officially by 2005.
Preparations have been moving at a glacial pace. Developing countries adamantly reject emission limits, arguing that rich countries that have been primarily responsible for emissions must take the lead. The situation became even more complicated in 2001 when the USA rejected the Kyoto protocol - partly in protest at a lack of 'meaningful participation' by the developing world.
It remains uncertain whether these deep divisions can be overcome, but the German agency's study suggests reasons for optimism. No single route to agreeing broader, deeper commitments will work alone, it concludes. But with creativity, flexibility and efforts to build trust, then there are enough technical approaches available to reach a compromise.
The report analyses the environmental, political and economic effectiveness of eight negotiating approaches already on the table and three additional models (see separate article, this issue). All the approaches would require industrialised countries to make emission cuts in the order of 50% by 2050, it concludes.
Whatever mix of approaches is adopted, a starting point is for industrialised countries to continue cutting emissions so as to build trust with developing countries and pave the way for their increasing involvement, the study concludes.
Developing countries should be encouraged to get involved early, but this should not necessarily mean 'participation' in the sense of targets. In any case, targets should have as little impact as possible on developing countries' economic growth.
Diverse forms of targets should be allowed, including not only absolute targets, but also emissions intensity relative to GDP, performance targets related to activity level -not GDP, and policies/measures targets based on actions rather than emission outcomes.