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Author: Wohland, Jan × DDC: 550 ×

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    Negative Emission Potential of Direct Air Capture Powered by Renewable Excess Electricity in Europe
    (Hoboken, NJ : Wiley-Blackwell, 2018) Wohland, Jan; Witthaut, Dirk; Schleussner, Carl-Friedrich
    The mitigation of climate change requires fast reductions in greenhouse gas emissions and calls for fundamental transitions of energy systems. In most places, the increased exploitation of variable renewable sources (wind and solar) forms the backbone of these transitions. To remain consistent with the Paris Agreement temperature goals, negative emission technologies will likely be needed to achieve net zero emissions in the second half of the century. In integrated assessment models, negative emissions are typically realized through land-based approaches. However, due to their coarse temporal and spatial resolution, such models might underestimate the potential of decentrally deployable and flexible technologies such as Direct Air Capture (DAC). Based on validated high-resolution power generation time series, we show that DAC can extract CO2 from the atmosphere and facilitate the integration of variable renewables at the same time. It is a promising flexibility provider as it can be ramped within minutes. Our results show that negative emissions of up to 500 Mt CO2/year in Europe may be achievable by using renewable excess energy only. Electricity systems with high shares of volatile renewables will induce excess generation events during which electricity is cheap thereby lowering the operational costs of DAC. If investment costs can be sufficiently reduced, this may render very energy intensive but highly flexible technologies such as DAC viable.
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    Climate information websites: an evolving landscape
    (Malden, MA : Wiley-Blackwell, 2017) Hewitson, Bruce; Waagsaether, Katinka; Wohland, Jan; Kloppers, Kate; Kara, Teizeen
    The climate change agenda is populated by actors and agencies with different objectives, values, and motivations, yet many seek decision scale climate information to inform policy and adaptation responses. A central element of this network of activity is the climate information website (CIW) that has seen a rapid and organic growth, yet with variable content and quality, and unfettered by any code of practice. This builds an ethical–epistemic dilemma that warrants assessment as the presence of CIWs contribute to real-world consequences and commitment. This study considers the context of CIW growth, and reviews a representative sample of CIWs to draw out key issues for consideration in CIW development. We assess content, function, and use-case value through a dual approach of a typology and user experience narratives to evaluate the general efficacy of a CIW. The typology reveals strong contrasts in content, complicated interfaces, and an overload of choice making it difficult to converge on a stable outcome. The narratives capture user experience and highlight barriers that include navigation difficulties, jargon laden content, minimal or opaque guidance, and inferred information without context about uncertainty and limits to skill. This illuminates four concerns: (1) the ethics of information provision in a context of real-world consequences; (2) interfaces that present barriers to achieving robust solutions; (3) weak capacity of both users and providers to identify information of value from the multimodel and multimethod data; and (4) inclusion of data that infer skill. Nonetheless, results provide a positive indication of a community of practice that is still maturing. WIREs Clim Change 2017, 8:e470. doi: 10.1002/wcc.470. For further resources related to this article, please visit the WIREs website.