Joint Global Change Research Institute

About: Joint Global Change Research Institute is a facility organization based out in Riverdale Park, Maryland, United States. It is known for research contribution in the topics: Greenhouse gas & Climate change. The organization has 197 authors who have published 934 publications receiving 62390 citations.

Vulcan and Hestia: High resolution quantification of fossil fuel CO 2 emissions

Abstract: Here we report on the Vulcan Project (vulcan.project.asu.edu/index.php), an effort to estimate fossil fuel CO2 emissions at local space/time scales through the use of "bottom-up", process-driven information. The Vulcan Project began as an answer to the need for a higher resolution North American fossil fuel CO2 emissions inventory. As a key component in the North American Carbon Program, Vulcan is now playing a critical role as a boundary constraint to inverse estimation of carbon sources and sinks. With the advent of denser CO2 monitoring, both in situ and remote, a higher resolution approach to inventory quantification is essential. The Vulcan Project has estimated United States fossil fuel CO2 emissions at the hourly time scale and at spatial scales below the county level (placed on a regular 10 km x 10 km grid) for the year 2002. Vulcan is built from a wide variety of observational data streams including regulated air pollutant emissions reporting, traffic monitoring, energy statistics, and US census data. In addition to these data sets, Vulcan relies on a series of modeling assumptions and constructs to interpolate in space, time and transform non-CO2 reporting into an estimate of CO2 combustion emissions. The recent version 2.0 of the Vulcan inventory has produced advances in a number of categories with particular emphasis on improved temporal structure. Onroad transportation emissions now avail of roughly 5000 automated traffic count monitors allowing for much improved diurnal and weekly time structure in our onroad transportation emissions. The Vulcan data product has been used for a regional inversion in the US and the potential bias correction from the utilization of previous fossil fuel CO2 emission data products is as high as 100% for large coherent regions in the United States. This emphasizes the potential for biased fossil fuel CO2 inventories to impact inverse results. Vulcan has also generated interest from decision-making communities and is now attempting to meet a variety of CO2 mitigation goals by providing process detail on emissions activities. This has led to the Hestia effort in which quantification has been attempted down to the individual building level within a single urban domain (Indianapolis, USA). A partner project, INFLUX, has begun in which the Hestia inventory is combined with aircraft monitoring and flux tower instrumentation to attempt the first urban-level bottom- up/top-down comparison. As with Vulcan, the Hestia effort has a variety of decision-support spin-offs including urban planning, energy efficiency planning in addition to CO2 mitigation planning at the urban/street level. Scoping has also begun on performing a Hestia approach for Los Angeles.

Planning Framework for Mesolevel Optimization of Urban Runoff Control Schemes

Abstract: A planning framework is developed to optimize runoff control schemes at scales relevant for regional planning at an early stage. The framework employs less sophisticated modeling approaches to allow a practical application in developing regions with limited data sources and computing capability. The methodology contains three interrelated modules: (1) the geographic information system (GIS)–based hydrological module, which aims at assessing local hydrological constraints and potential for runoff control according to regional land-use descriptions; (2) the grading module, which is built upon the method of fuzzy comprehensive evaluation. It is used to establish a priority ranking system to assist the allocation of runoff control targets at the subdivision level; and (3) the genetic algorithm-based optimization module, which is included to derive Pareto-based optimal solutions for mesolevel allocation with multiple competing objectives. The optimization approach describes the trade-off between differ...

Evaluating changes of biomass in global vegetation models: the role of turnover fluctuations and ENSO events

Abstract: This paper evaluates the ability of eight global vegetation models to reproduce recent trends and inter-annual variability of biomass in natural terrestrial ecosystems. For the purpose of this evaluation, the simulated trajectories of biomass are expressed in terms of the relative rate of change in biomass (RRB), defined as the deviation of the actual rate of biomass turnover from its equilibrium counterpart. Cumulative changes in RRB explain long-term changes in biomass pools. RRB simulated by the global vegetation models is compared with its observational equivalent, derived from vegetation optical depth reconstructions of above-ground biomass (AGB) over the period 1993–2010. According to the RRB analysis, the rate of global biomass growth described by the ensemble of simulations substantially exceeds the observation. The observed fluctuations of global RRB are significantly correlated with El Niño Southern Oscillation events (ENSO), but only some of the simulations reproduce this correlation. However, the ENSO sensitivity of RRB in the tropics is not significant in the observation, while it is in some of the simulations. This mismatch points to an important limitation of the observed AGB reconstruction to capture biomass variations in tropical forests. Important discrepancies in RRB were also identified at the regional scale, in the tropical forests of Amazonia and Central Africa, as well as in the boreal forests of north-western America, western and central Siberia. In each of these regions, the RRBs derived from the simulations were analyzed in connection with underlying differences in net primary productivity and biomass turnover rate —as a basis for exploring in how far differences in simulated changes in biomass are attributed to the response of the carbon uptake to CO2 increments, as well as to the model representation of factors affecting the rates of mortality and turnover of foliage and roots. Overall, our findings stress the usefulness of using RRB to evaluate complex vegetation models and highlight the importance of conducting further evaluations of both the actual rate of biomass turnover and its equilibrium counterpart, with special focus on their background values and sources of variation. In turn, this task would require the availability of more accurate multi-year observational data of biomass and net primary productivity for natural ecosystems, as well as detailed and updated information on land-cover classification. © 2018 The Author(s). Published by IOP Publishing Ltd Environ. Res. Lett. 13 (2018) 075002

An integrated assessment of a low coal low nuclear future energy system for Taiwan

Abstract: The goal of this study is to analyze decarbonization pathways for Taiwan, in line with the goals of the Paris Agreement: achieving a 2 °C increase by 2100, aiming for 1.5 °C. We use GCAM, an integrated assessment model, in order to evaluate the different implications of decarbonization in this region. We find that, if Taiwan wants to be consistent with Paris’ goals, it needs an aggressive electrification of end-use sectors, a rapid scale-up of renewable energies, as well as increased efficiencies in buildings, transportation and industry. Transportation and industry present greater decarbonization challenges than buildings, and negative emission technologies become crucial. We also identify opportunities where future research would enrich decarbonization analyses for Taiwan.

Climate scenarios and their relevance and implications for impact studies

Abstract: In this chapter, we introduce the integrated scenario framework that currently underpins future climate modeling, impact assessment, and mitigation studies. We describe the basic conceptual design of the shared socioeconomic pathways (SSP) and their role in the generation of future emission pathways. This will elucidate the origin and rationale of the pathways used as external forcings for climate model simulations, both the past representative concentration pathways and the design of the current set used by CMIP6 experiments. From a complementary perspective, we describe the development and availability of SSP elements that in addition to driving the production of external forcings can (should) be used to characterize and quantify the human dimension of future change. Projections of population and gross domestic product growth, demographic characteristics and income distribution, assumptions about adaptation capacity, technology development, etc. are available at a range of spatial and temporal scales and should enable a holistic assessment of regional and sectoral impacts taking into account both the physical and socioeconomic drivers of change. A brief review of the existing recent literature utilizing the integrated approach and spanning a wide range of impact domains is given, and over this background, specific examples of analysis integrating the physical and human dimension of change using the available scenarios are provided for a number of different sectors: public health (e.g., population exposure to heat extremes); agricultural production (e.g., changes in food prices and trade driven by productivity changes due to climate); coastal areas exposure to hazards (e.g., changes in structures at risk from tropical cyclone changes in intensity and frequency).