The Third National Climate Assessment and Regional Climate Scenarios as Sience and Communication Tools

English Abstract:

The Third National Climate Assessment (NCA) had an intended audience, primarily including decision/policy-makers in government and industry. In general, these are not scientists. While the NCA was anticipated for its authoritative climate change analysis, in an effort to communicate to non-scientists, the NCA was also a vanguard in climate communication. From the cutting-edge website to the organization of information, the Assessment was accessed by many demographics. Additionally, as part of development of the Third NCA, a set of uniform regional climate change scenario products were prepared from climate model simulations in the CMIP3 and CMIP5 archives. These products directly supported the development of the NCA3 regional chapters and provided important information for sectoral chapters where sensitivities to climate often have a strong regional dependency. The underlying climate model data is characterized by a spectrum of uncertainties, but provides considerable scientific insights into the likely response of the climate system to increased greenhouse gas forcing.

In the development of the NCA3, our challenge was to produce synthesized analyses that conveyed the essential information in transparent, scientifically-rigorous, and easily-understandable formats. These diverse requirements are not easily achieved. The crafting of language describing such scenarios, and the underlying scientific confidence, was an additional challenge for the authors. Finally, the gathering of complex metadata to describe these products was considered an essential component to provide credibility. The system used for collecting and presenting this metadata not only met federally mandated requirements, but demonstrated a sustainable process that can be used for other applications and serve as a communications mechanism for decision-makers.

We will describe the process of synthesizing climate model data for use by the NCA3 authors in producing the report. A number of products were primarily for the authors to use in crafting language. Other products were included in the report and thus intended for the broad NCA3 target audience. We will also discuss specific examples where the crafting of the report language was critical to communicate accurately and comprehensively the nature of the scientific understanding.