Long-run evolution of the global economy: 2. Hindcasts of innovation and growth
Summary: This paper examines the reliability of a simple physics-based model for how global civilization grows. Initializing the model with growth trends from the 1950s, it attains skill scores greater than 90% at predicting growth trends in the global GDP and world energy consumption over the last decade. This suggests that civilization as a whole evolves as a deterministic response to resource availability and environmental decay, needing no explicit consideration of people or their policies.
Earth Syst. Dynam. Discuss., 6, 655-698, doi:10.5194/esdd-6-655-2015, 2015
Prevailing climatic trends and runoff response from Hindukush–Karakoram–Himalaya, upper Indus basin
Earth Syst. Dynam. Discuss., 6, 579-653, doi:10.5194/esdd-6-579-2015, 2015
Large differences in land use emission quantifications implied by definition discrepancies
Summary: Estimates for land use change CO2 emissions (eLUC) rely on different approaches, implying conceptual differences in what eLUC represents. We use an Earth System Model and quantify differences between commonly applied methods to be ~20% for historical eLUC but increasing under a future scenario. To reduce uncertainty, we suggest a framework to define eLUC components and recommend to assume constant environmental conditions for the quantification of eLUC in global carbon budget accounting.
Earth Syst. Dynam. Discuss., 6, 547-577, doi:10.5194/esdd-6-547-2015, 2015
The Scaling LInear Macroweather model (SLIM): using scaling to forecast global scale macroweather from months to decades
Summary: Numerical climate model forecast the weather well beyond the deterministic limit. In this “macroweather” regime, they are random number generators. Stochastic models can have more realistic noises and can be forced to converge to the real world climate. Existing stochastic models do not exploit the very long atmospheric and oceanic memories. Our new Scaling Linear Macroweather (SLIM) model exploits this to make forecasts more accurate than GCM’s and with skill up to decades.
Earth Syst. Dynam. Discuss., 6, 489-545, doi:10.5194/esdd-6-489-2015, 2015
Topology of sustainable management in dynamical Earth system models with desirable states
Summary: The debate about a safe and just operating space for humanity and the possible pathways towards and within it requires an analysis of the inherent dynamics of the Earth System and of the options for influencing its evolution. We present and illustrate with examples a conceptual framework for performing such an analysis not in a quantitative, optimizing mode, but in a qualitative way that emphasizes the main decision dilemmata that one may face in the sustainable management of the Earth System.
Earth Syst. Dynam. Discuss., 6, 435-488, doi:10.5194/esdd-6-435-2015, 2015
Inferring global wind energetics from a simple Earth system model based on the principle of maximum entropy production
Summary: This paper proposes a method to infer global wind energetics of the atmosphere. It uses the energy fluxes obtained with a climate box-model previously proposed by Herbert et al., based on the maximization of entropy production (MEP) principle, to compute annual mean winds. Specific details of the circulation are not recovered, as the atmosphere is represented with only one layer, but global figures are well captured.
Earth Syst. Dynam. Discuss., 6, 407-433, doi:10.5194/esdd-6-407-2015, 2015
Climate and carbon cycle dynamics in a CESM simulation from 850–2100 CE
Summary: We present the first last millennium simulation with the Community Earth System Model (CESM) including an interactive carbon cycle in both ocean and land component. Volcanic eruptions emerge as strongest forcing factor for the preindustrial climate and carbon cycle. We estimate the climate-carbon cycle feedback in CESM to be at the lower bounds of empirical estimates (1.3 ppm/°C). The time of emergence for interannual global land and ocean carbon uptake rates are 1947 and 1877, respectively.
Earth Syst. Dynam. Discuss., 6, 351-406, doi:10.5194/esdd-6-351-2015, 2015
Ice-supersaturation and the potential for contrail formation in a changing climate
Summary: Aviation can impact on climate via contrails, which are often clearly visible in the sky. Contrail formation requires particular cold/moist atmospheric conditions at cruise altitudes. Climate change is expected to change these conditions. Using simulations from several climate models we conclude that by the end of the century the probability of contrail formation could decrease in the tropics by 9% and increase in polar regions by 5%. There is no consenus on the likely change in mid-latitudes.
Earth Syst. Dynam. Discuss., 6, 317-349, doi:10.5194/esdd-6-317-2015, 2015
Resource acquisition, distribution and end-use efficiencies and the growth of industrial society
Summary: This paper uses observations of global and national energy use to attempt to show that the growth in energy use over the last 160 years can be related to the distribution constraints imposed by the networks that link environmentally-derived resources to points of end use. Having accounted for the distribution efficiency of this global-scale network, we speculate that the observed long-run return rate on energy of ~2.4 %/yr requires regulated deployment of acquisition and end use efficiencies.
Earth Syst. Dynam. Discuss., 6, 133-168, doi:10.5194/esdd-6-133-2015, 2015
Migration and global environmental change: methodological lessons from mountain areas of the global South
Earth Syst. Dynam. Discuss., 5, 1711-1749, doi:10.5194/esdd-5-1711-2014, 2014
Optimizing cropland cover for stable food production in Sub-Saharan Africa using simulated yield and Modern Portfolio Theory
Summary: Food security is defined as stable access to food of good nutritional quality. In regions where food security is highly dependent on local production it is thus of importance to produce not only enough calories but also to minimize variation in yield. This trade-off is investigated here using simulated crop yield and by selecting relative distributions of crops. The results show a large potential to either increase food production or to decrease its variance by applying optimized crop selection.
Earth Syst. Dynam. Discuss., 5, 1571-1606, doi:10.5194/esdd-5-1571-2014, 2014