Identifying Sustainability and Knowledge Gaps in Socio-Economic Pathways Vis-à-Vis the Sustainable Development Goals

With the Sustainable Development Goals (SDGs), the global community has set itself an ambitious development agenda. Current analytical and quantitative modeling capabilities fall short of being able to capture all 17 SDGs and their targets. Even highly ambitious and optimistic pathways currently used in research, such as SSP1/SSP1-2.6, do not meet all SDGs (sustainability gaps) and fail to provide information on some of them (knowledge gaps). We show that for research and modeling purposes, the SDG targets can serve as a basis but need to be operationalized to reduce complexity and also to account for long-term sustainability concerns beyond 2030. We have explored here the requirements for assessing more comprehensively the sustainability of development pathways, guided by holistic interpretation of the SDGs to enable an assessment of the potential embedded synergies and trade-offs between the economic, social and environmental objectives. We see this as call for action for science to work on filling these gaps. At the same time, this is also a call for policy makers and the global community to close the sustainability gaps that emerge from such analysis. We anticipate that such analysis will provide useful information for policy advice and investment decisions during implementation of the UN 2030 Agenda

Review of CGIAR Research Programs Governance and Management: Final Report

The Review of CGIAR Research Program Governance and Management was requested by the CGIAR Consortium and approved by the Fund Council in November 2012. The Independent Evaluation Arrangement (IEA) is responsible for the review, which was carried out between June 2013 and January 2014. At the time the review was initiated, Consortium Research Programs (CRP) governance and management structures were in place or approved for each CRP. This enabled the review to “take stock of experience so far, identify issues and provide lessons from existing CRPs and elsewhere which can be applicable to other CRPs” (Annex 1, Review Terms of Reference)

Dynamics of Alpha-Helix Formation in the CSAW Model

We study the folding dynamics of polyalanine (Ala$_{20}$), a protein fragment with 20 residues whose native state is a single alpha helix. We use the CSAW model (conditioned self-avoiding walk), which treats the protein molecule as a chain in Brownian motion, with interactions that include hydrophobic forces and internal hydrogen bonding. We find that large scale structures form before small scale structures, and obtain the relevant relaxation times. We find that helix nucleation occurs at two separate points on the protein chain. The evolution of small and large scale structures involve different mechanisms. While the former can be describe by rate equations governing the growth of helical content, the latter is akin to the relaxation of an elastic solid.Comment: 18 pages, 10 figure

Dynamics of Counterion Condensation

Using a generalization of the Poisson-Boltzmann equation, dynamics of counterion condensation is studied. For a single charged plate in the presence of counterions, it is shown that the approach to equilibrium is diffusive. In the far from equilibrium case of a moving charged plate, a dynamical counterion condensation transition occurs at a critical velocity. The complex dynamic behavior of the counterion cloud is shown to lead to a novel nonlinear force-velocity relation for the moving plate.Comment: 5 pages, 1 ps figure included using eps

Denaturation of Heterogeneous DNA

The effect of heterogeneous sequence composition on the denaturation of double stranded DNA is investigated. The resulting pair-binding energy variation is found to have a negligible effect on the critical properties of the smooth second order melting transition in the simplest (Peyrard-Bishop) model. However, sequence heterogeneity is dramatically amplified upon adopting a more realistic treatment of the backbone stiffness. The model yields features of ``multi-step melting'' similar to those observed in experiments.Comment: 4 pages, LaTeX, text and figures also available at http://matisse.ucsd.edu/~hw

A Simple Model for the DNA Denaturation Transition

We study pairs of interacting self-avoiding walks on the 3d simple cubic lattice. They have a common origin and are allowed to overlap only at the same monomer position along the chain. The latter overlaps are indeed favored by an energetic gain. This is inspired by a model introduced long ago by Poland and Sheraga [J. Chem. Phys. {\bf 45}, 1464 (1966)] for the denaturation transition in DNA where, however, self avoidance was not fully taken into account. For both models, there exists a temperature T_m above which the entropic advantage to open up overcomes the energy gained by forming tightly bound two-stranded structures. Numerical simulations of our model indicate that the transition is of first order (the energy density is discontinuous), but the analog of the surface tension vanishes and the scaling laws near the transition point are exactly those of a second order transition with crossover exponent \phi=1. Numerical and exact analytic results show that the transition is second order in modified models where the self-avoidance is partially or completely neglected.Comment: 29 pages, LaTeX, 20 postscript figure

Scaling and Universality in the Counterion-Condensation Transition at Charged Cylinders

We address the critical and universal aspects of counterion-condensation transition at a single charged cylinder in both two and three spatial dimensions using numerical and analytical methods. By introducing a novel Monte-Carlo sampling method in logarithmic radial scale, we are able to numerically simulate the critical limit of infinite system size (corresponding to infinite-dilution limit) within tractable equilibration times. The critical exponents are determined for the inverse moments of the counterionic density profile (which play the role of the order parameters and represent the inverse localization length of counterions) both within mean-field theory and within Monte-Carlo simulations. In three dimensions (3D), correlation effects (neglected within mean-field theory) lead to an excessive accumulation of counterions near the charged cylinder below the critical temperature (condensation phase), while surprisingly, the critical region exhibits universal critical exponents in accord with the mean-field theory. In two dimensions (2D), we demonstrate, using both numerical and analytical approaches, that the mean-field theory becomes exact at all temperatures (Manning parameters), when number of counterions tends to infinity. For finite particle number, however, the 2D problem displays a series of peculiar singular points (with diverging heat capacity), which reflect successive de-localization events of individual counterions from the central cylinder. In both 2D and 3D, the heat capacity shows a universal jump at the critical point, and the energy develops a pronounced peak. The asymptotic behavior of the energy peak location is used to locate the critical temperature, which is also found to be universal and in accordance with the mean-field prediction.Comment: 31 pages, 16 figure

Putting multidimensional inequalities in human wellbeing at the centre of transitions

Jason Hickel and colleagues reported large inequalities in global resource extraction, which has led to an ecological crisis. Hickel and colleagues show that high-income countries are responsible for 74% of global excess material use of equitable and sustainable boundaries from 1970 to 2017. Therefore, the authors suggested that high-income countries should undergo post-growth and degrowth transformations. Adding to Hickel and colleagues’ convincing assessment, we want to introduce a broader focus on distributive justice in human and planetary wellbeing, which goes beyond resource extraction. We provide a broad view of the multiple dimensions of inequality, capturing enablers (eg, material use) and the effects of resource use that act as barriers to human wellbeing (eg, air pollution). We follow the theory of human needs with the universal goal of avoiding serious harm across the globe and across generations, and enabling capabilities and opportunities needed for a decent life. We argue that such a comprehensive focus on human and planetary wellbeing allows responsibilities to be shared more fairly in any transition process

A dynamic systems approach to harness the potential of social tipping

Social tipping points are promising levers to achieve net-zero greenhouse gas emission targets. They describe how social, political, economic or technological systems can move rapidly into a new state if cascading positive feedback mechanisms are triggered. Analysing the potential of social tipping for rapid decarbonization requires considering the inherent complexity of social systems. Here, we identify that existing scientific literature is inclined to a narrative-based account of social tipping, lacks a broad empirical framework and a multi-systems view. We subsequently outline a dynamic systems approach that entails (i) a systems outlook involving interconnected feedback mechanisms alongside cross-system and cross-scale interactions, and including a socioeconomic and environmental injustice perspective (ii) directed data collection efforts to provide empirical evidence for and monitor social tipping dynamics, (iii) global, integrated, descriptive modelling to project future dynamics and provide ex-ante evidence for interventions. Research on social tipping must be accordingly solidified for climate policy relevance

Building back better: Granular energy technologies in green recovery funding programs

Granular energy technologies with smaller unit sizes and costs deploy faster, create more jobs, and distribute benefits more widely than lumpy large-scale alternatives. These characteristics of granularity align with the aims of fiscal stimulus in response to COVID-19. We analyze the technological granularity of 93 green recovery funding programs in France, Germany, South Korea, and the UK that target £72.9 billion for low-carbon energy technologies and infrastructures across five emissions-intensive sectors. We find that South Korea’s “New Deal” program is the most technologically granular with strong weighting toward distributed renewables, smart technologies, electric vehicle charge points, and other relatively low unit cost technologies that are quick to deploy. The UK has the least granular portfolio, concentrating large amounts of public money on small numbers of mega-scale energy projects with high implementation risks. We demonstrate how technological granularity has multiple desirable characteristics of green recovery: jobs, speed, and distributed benefits