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Many of the global and regional gridded emission inventories used in atmospheric are based on downscaling techniques. Regardless of their limitations compared to locally-constructed mechanistic emission inventories, such gridded datasets will keep a key role of transferring the information reported as emission inventories into science-based emission verification support (EVS) systems. Given the use of inverse modeling in the EVS systems, characterizing errors and biases associated with the downscaled emission field is critical in order to obtain robust verification results. However, such error characterization is often challenging due to the lack of objective metrics. This study compares downscaled emissions from the ODIAC global high-resolution dataset to values taken from the reported inventories and from other independent emission products with the intent of assessing the validity (e.g., error, bias, or accuracy ) of downscaled emissions databases at different policy relevant scales. ODIAC is based on its flagship high-resolution emission downscaling using satellite-observed nighttime lights (NTL) and point source information. The sole use of the NTL proxy for diffuse emissions has limitations. However, that provides a good opportunity to solely evaluate the performance of NTL as an emission proxy. It is now relatively straightforward to create detailed, high-resolution emission maps due to the advancements in geospatial modeling. However, such geospatial modeling techniques, which combine multiple pieces of information from different sources, are often neither validated nor even carefully evaluated. As commonly done in previous emission uncertainty studies, we use the differences and agreements as a proxy for errors and improvements. We collect emission information reported at policy relevant scales, such as state/province/prefecture, cities and facility level (only for point sources). We also use locally-constructed fine-grained emission inventories as a quasi-truth for the emission distribution. We also assess the performance of NASA’s Black Marble NTL product suites as a new emission proxy in relation to current the ODIAC proxy that is based on older NTL datasets. We also look at how these emission differences translate into atmospheric concentration differences using high-resolution WRF simulations. Based on results from the comparison, we identify and discuss the challenges and limitations in the use of downscaled emissions in carbon monitoring at different policy-relevant scales, especially at the city level, and propose possible ways to overcome some of the challenges and provide emission fields that are useful for both science and policy applications.

The livestock sector is a major contributor to agricultural greenhouse gas (GHG) and nitrogen (N) emissions and efforts are being made to reduce these emissions. National emission inventories are the main tool for reporting emissions. They have to be consistent, comparable, complete, accurate and transparent. The quality of emission inventories is affected by the reporting methodology, emission factors and knowledge of individual sources. In this paper, we investigate the effects of moving from the 1996 IPCC Guidelines for National Greenhouse Gas Inventories to the 2006 IPCC Guidelines on the emission estimates from the livestock sector. With Austria as a case study, we estimated the emissions according to the two guidelines, revealing marked changes in emission estimates from different source categories resulting from changes in the applied methodology. Overall estimated GHG emissions from the livestock sector decreased when applying the IPCC 2006 methodology, except for emissions from enteric fermentation. Our study revealed shifts in the relative importance of main emission sources. While the share of CH4 emissions from enteric fermentation and manure management increased, the share of N2O emissions from manure management and soils decreased. The most marked decrease was observed for the share of indirect N2O emissions. Our study reveals a strong relationship between the emission inventory methodology and mitigation options as mitigation measures will only be effective for meeting emission reduction targets if their effectiveness can be demonstrated in the national emission inventories. We include an outlook on the 2019 IPCC Refinement and its potential effects on livestock emissions estimates. Emission inventory reports are a potent tool to show the effect of mitigation measures and the methodology prescribed in inventory guidelines will have a distinct effect on the selection of mitigation measures.

FarmClim aims at contributing to a more considerate use of nitrogen in Austrian agriculture. The transdisciplinary research project attempts to tackle the “science-policy gap” by using a participatory approach, that is, stakeholders influence the research process as much as the scientists strive for the implementation of their ideas. This paper describes the project design and communication processes. Full integration of practice partners adds to the complexity of the project's structure, but brings consider able benefits right from the outset. Taking advantage of the existing institutional setting of FarmClim partners, we expect to maintain expert consultancy beyond the lifetime of the project, helping agriculture to meet the challenges of environmental and economic performance of a producing agriculture.