Knowing how to change. Environmental policy learning and transfer

New knowledge, changing expectations and practical experience are being applied by policy actors at many different levels, in a process of 'adaptive social learning'. Yet learning runs into numerous obstacles and blockages. Knowledge is seen as a key ingredient of learning and shifts in understanding may arise from multiple sites, resulting in either more fundamental reframing of policy problems, sometimes challenging long-held conventional wisdoms, or more incremental changes focused on more marginal instrumental changes. Whatever its source, new knowledge and the prospect of change that it brings, frequently threatens existing policy relationships and structures of power. Responses to scientific and practical knowledge are highly differentiated. Stephens identifies two processes which she names 'snowballs' (the accumulation of research impacts within policy elites) and 'whispers' (the reinterpretation of research findings in broader constituencies). Environmental policy learning is most effectively achieved by adopting a more flexible and iterative model of the policy process.