Long term ecological changes such as climate change, which endangers at least

the exisiting quality of life in many societies, involve two main governance

challenges. First, due to the long-term and less visible character of those

ecological changes which often span over more than one generation, proactive

and long-term oriented policy strategies are necessary before the full

consequences are visible. Second, according to the state of knowledge, the

current development of economy and society in industrialised countries is not

ecologically sustainable and there is a need for considerable technological,

institutional and social changes to reach sustainable social-ecological pathways

(e.g. Luks 2005; Meadowcroft 2005). For example greenhouse gas emissions of

industrial countries would need to be reduced by 80 to 95 per cent between 1990

and 2050 if dangerous climate change is to be avoided (e.g. IPCC 2007).