While mainstream scientific knowledge production has been extensively examined in the academic literature, comparatively little is known about alternative networks of scientific knowledge production. Online sources such as blogs are an especially under-investigated site of knowledge contestation. Using degree centrality and node betweenness tests from social network analysis, and thematic content analysis of individual posts, this research identifies and critically examines the climate sceptical blogosphere and investigates whether a focus on particular themes contributes to the positioning of the most central blogs. A network of 171 individual blogs is identified, with three blogs in particular found to be the most central: Climate Audit, JoNova and Watts Up With That. These blogs predominantly focus on the scientific element of the climate debate, providing either a direct scientifically-based challenge to mainstream climate science, or a critique of the conduct of the climate science system. This overt scientific framing, as opposed to explicitly highlighting differences in values, politics, or ideological worldview, appears to be an important contributory factor in the positioning of the most central blogs. It is suggested that these central blogs are key protagonists in a process of attempted expert knowledge de-legitimisation and contestation, acting not only as translators between scientific research and lay audiences, but, in their reinterpretation of existing climate science knowledge claims, are acting themselves as alternative public sites of expertise for a climate sceptical audience.

The 2009 Renewable Energy Directive mandates EU member-states' road transport fuel to comprise a minimum of 10% renewable content by 2020. This target is expected to be met predominantly from biofuels. However, scientifi c evidence is increasingly questioning the ability of biofuels to reduce greenhouse gas emissions when factors such as indirect landuse change are taken into consideration. This paper interrogates the 10% target, critically assessing its political motivations, use of scientifi c evidence and the actions of an individual policy entrepreneur who played a central role in its adoption. We fi nd that the commitment of EU decision-making bodies to internal guidelines on the use of expertise and the precautionary principle was questionable, despite the scientifi c uncertainty inherent in the biofuels debate. Imperatives located in the political space dominated scientifi c evidence and led to a process of 'policy-based evidence gathering' to justify the policy choice of a 10% renewable energy/biofuels target.

Public perceptions of the climate debate predominantly frame the key actors as climate scientists (CSs) versus sceptical voices (SVs); however it is unclear why CSs and SVs choose to participate in this antagonistic and polarised public battle. A narrative interview approach is used to better understand the underlying rationales behind 22 CSs' and SVs' engagement in the climate debate, potential commonalities, as well as each actor's ability to be critically selfreflexive. Several overlapping rationales are identified including a sense of duty to publicly engage, agreement that complete certainty about the complex assemblage of climate change is unattainable, and that political factors are central to the climate debate. We argue that a focus on potential overlaps in perceptions and rationales as well as the ability to be critically selfreflexive may encourage constructive discussion amongst actors previously engaged in purposefully antagonistic exchange on climate change.

Labels play an important role in opinion formation, helping to actively construct perceptions and reality, and place individuals into context with others. As a highly complex issue, climate change invites a range of different opinions and dialogs about its causes, impacts, and action required. However, the polarized labels used in the climate change debate, such as skeptic or alarmist, are both reflecting and helping to frame the debate as antagonistic and combative. This paper critically reviews the literature on climate opinion labels, and the efforts taken within an academic context to categorize differences, create new taxonomies of more detailed sub‐labels, or create or argue for the use of new labels such as denier or contrarian. By drawing on research on typologies of climate opinions, problems with labeling constructs and discussions around context and the implications for science‐policy dialog, we argue that climate labels, both as constructed in the academic literature, and as applied in science and policy debates, are serving to isolate, exclude, ignore, and dismiss claims‐makers of all types from constructive dialog. It suggests that context has been inadequately considered by the literature and that an emphasis on labels is accentuating division and diverting attention away from a focus on underlying motivations, which may be more conducive toward increasing public understanding and encouraging communication across this polarized debate. WIREs Clim Change 2015, 6:239–254. doi: 10.1002/wcc.332 This article is categorized under: Perceptions, Behavior, and Communication of Climate Change > Communication Social Status of Climate Change Knowledge > Knowledge and Practice

Contestation over knowledge claims, including their legitimacy as an input to policy decisionmaking, does not end at the moment of policy creation. Policies continue to be made and unmade during the implementation phase. Drawing from work on knowledge controversies, and building on Puchala's (1975) concept of post-decisional politics, we investigate the implementation of climate change policy in New Zealand and the United Kingdom. We identify politically salient post-decisional logics of inaction which have been used to justify delaying or diluting climate policy implementation in both countries. In New Zealand, knowledge controversy has had little or no influence over decision-making, with political rationales in the form of the current national economic interest and cost-based logics prevailing.Conversely, arguments emphasising scientific uncertainty have achieved political traction in the United Kingdom, creating a "fog of distrust" instrumental in draining political capital from the active implementation of climate policy. Explanatory factors such as structural economic considerations and different values placed on science as an input to policy-making are discussed, highlighting the importance of being attentive to the fluidity of knowledge controversies as they achieve salience and legitimacy according to the specificities of time and place.