Bioeconomic meta-modelling of Indonesian agroforests as carbon sinks

In many areas of developing countries, economic and institutional factors often combine to give farmers incentives to clear forests and repeatedly plant food crops without sufficiently replenishing the soils. These activities lead to large-scale land degradation and contribute to global warming through the release of greenhouse gases into the atmosphere. We investigate whether agroforestry systems might alleviate these trends when carbon-credit payments are available under the Clean Development Mechanism of the Kyoto Protocol. A meta-modelling framework is adopted, comprising an econometric-production model of a smallholding in Sumatra. The model is used within a dynamic-programming algorithm to determine optimal combinations of tree/crop area, tree-rotation length, and firewood harvest. Results show the influence of soil-carbon stocks and discount rates on optimal strategies and reveal interesting implications for joint management of agriculture and carbon.bio-economic meta-modelling, Indonesia, agroforestry, carbon credits, dynamic programming, Environmental Economics and Policy, Resource /Energy Economics and Policy,

Optimal Land-Use Decisions in the Presence of Carbon Payments and Fertilizer Subsidies: An Indonesian Case Study

The Clean Development Mechanism of the Kyoto Protocol provides the opportunity for smallholders to receive financial rewards for adopting tree-based systems that are sustainable. In this paper a meta-model is developed to simulate interactions between trees, crops and soils under a range of management regimes for a smallholding in Sumatra. The model is used within a dynamic-programming algorithm to determine optimal tree/crop areas, tree-rotation lengths, firewood-harvest and fertilizer application rates for a landholder faced with deteriorating land quality and opportunities to receive carbon credits and fertiliser subsidies. It is found th at profit maximising management strategies depend on initial soil quality. For example, incentives to participate in carbon projects only exist when the soil is degraded because the opportunity cost of the forgone crop production is low. Also, when soil-carbon stocks are low only trees should be grown and residues added to the soil to increase carbon stocks until a threshold level is reached, when it becomes optimal to switch to a steady-state system of crops with fertiliser. In this case, tree rotation lengths depend on carbon and fertiliser prices; where increases in these prices decrease the opportunity cost of growing trees and allow for longer rotations. If, however, the initial soil-carbon stock is high, the profit-maximising strategy is to grow only crops and use fertiliser, which initially depletes the soil of carbon until a steady state is reached and maintained.Land Economics/Use,

Tree-crop interactions and their environmental and economic implications in the presence of carbon-sequestration payments

Growing trees with crops has environmental and economic implications. Trees can help prevent land degradation and increase biodiversity while at the same time allow for the continued use of the land to produce agricultural crops. In fact, growing trees alongside crops is known to improve both the productivity and sustainability of the land. However, due to high labour-input requirements, high costs of establishment, and delayed revenue returns, trees are often not economically attractive to landholders. Because of the Kyoto Protocol, and the growing emphasis on market-based solutions to environmental problems, the ability of trees to sequester and store CO2 has altered the economic landscape of agroforestry systems. The economic and management implications of carbon-sequestration payments on agroforestry systems are addressed in this study using a bioeconomic modelling approach. An agroforestry system in Indonesia is simulated using a biophysical process model. A general economic analysis of this system, from the standpoint of individual landholders, is then developed and the implications for management and policy are discussed.agroforestry, bioeconomics, tree/crop interactions, carbon credits, baselines, Environmental Economics and Policy, Land Economics/Use,

Carbon-accounting methods and reforestation incentives

The emission of greenhouse gases, particularly carbon dioxide, and the consequent potential for climate change are the focus of increasing international concern. Temporary land-use change and forestry projects (LUCF) can be implemented to offset permanent emissions of carbon dioxide from the energy sector. Several approaches to accounting for carbon sequestration in LUCF projects have been proposed. In the present paper, the economic implications of adopting four of these approaches are evaluated in a normative context. The analysis is based on simulation of Australian farm–forestry systems. Results are interpreted from the standpoint of both investors and landholders. The role of baselines and transaction costs are discussed.Resource /Energy Economics and Policy,

Knowledge co-production for Indigenous adaptation pathways: transform post-colonial articulation complexes to empower local decision-making

Co-production between scientific and Indigenous knowledge has been identified as useful to generating adaptation pathways with Indigenous peoples, who are attached to their traditional lands and thus highly exposed to the impacts of climate change. However, ignoring the complex and contested histories of nation-state colonisation can result in naïve adaptation plans that increase vulnerability. Here, through a case study in central Australia, we investigate the conditions under which co-production between scientific and Indigenous knowledge can support climate change adaptation pathways among place-attached Indigenous communities. A research team including scientists, Ltyentye Apurte Rangers and other staff from the Central Land Council first undertook activities to co-produce climate change presentations in the local Arrernte language; enable community members to identify potential adaptation actions; and implement one action, erosion control. Second, we reflected on the outcomes of these activities in order to unpack deeper influences. Applying the theory of articulation complexes, we show how ideologies, institutions and economies have linked Indigenous societies and the establishing Australian nation-state since colonisation. The sequence of complexes characterised as frontier, mission, pastoral, land-rights, community-development and re-centralisation, which is current, have both enabled and constrained adaptation options. We found knowledge co-production generates adaptation pathways when: (1) effective methods for knowledge co-production are used, based on deeply respectful partnerships, cultural governance and working together through five co-production tasks—prepare, communicate, discuss, bring together and apply; (2) Indigenous people have ongoing connection to their traditional territories to maintain their Indigenous knowledge; (3) the relationship between the Indigenous people and the nation-state empowers local decision-making and learning, which requires and creates consent, trust, accountability, reciprocity, and resurgence of Indigenous culture, knowledge and practices. These conditions foster the emergence of articulation complexes that enable the necessary transformative change from the colonial legacies. Both these conditions and our approach are likely to be relevant for place-attached Indigenous peoples across the globe in generating climate adaptation pathways

Hygroscopic Behavior of NaCl-Bearing Natural Aerosol Particles Using Environmental Transmission Electron Microscopy

We used conventional and environmental transmission electron microscopes to determine morphology, composition, and water uptake of individual natural inorganic aerosol particles collected from industrial pollution plumes and from clean and polluted marine environments. Five particle types are described in detail. They range from relatively insoluble mineral grains to internally mixed particles containing NaCl with other soluble or relatively insoluble material. We studied the hygroscopic behavior of these particles from 0 to 100% relative humidity (RH). Relatively insoluble materials do not take up water over the experimental RH range. Single crystals of NaCl from both natural and laboratory sources have a well-defined deliquescence point of approximately 76% RH at 291 K. NaCl-bearing aggregate particles appear to deliquesce between 74 and 76% RH (same RH within error) when NaCl is internally mixed with relatively insoluble phases, but the particles deliquesce at lower RH when aggregated with other soluble phases such as NaNO3. For all NaCl-bearing particles studied, hygroscopic growth is pronounced above 76% RH, and water uptake by the particles is dominated by the soluble phase. Furthermore, the soluble phase initiating deliquescence controls the locus of further hygroscopic growth of the aggregate particle. Our results demonstrate that composition and mixing state affect water uptake of natural aerosol particles. Furthermore, internally mixed particles are confirmed to deliquesce at lower RH values than predicted from the individual components

Hygroscopic Behavior and Liquid-Layer Composition of Aerosol Particles Generated from Natural and Artificial Seawater

Sea-salt aerosol (SSA) particles affect the Earth\u27s radiative balance and moderate heterogeneous chemistry in the marine boundary layer. Using conventional and environmental transmission electron microscopes (ETEM), we investigated the hygroscopic growth and liquid-layer compositions of particles generated from three types of aqueous salt solutions: sodium chloride, laboratory-synthesized seawater (S-SSA particles), and natural seawater (N-SSA particles). Three levels of morphological change were observed with the ETEM as the laboratory-generated particles were exposed to increasing relative humidity (RH). The first level, onset of observable morphological changes, occurred on average at 70, 48, and 35% RH for the NaCl, S-SSA, and N-SSA particles, respectively. The second level, rounding, occurred at 74, 66, and 57% RH for NaCl, S-SSA, and N-SSA particles, respectively. The third level, complete deliquescence, occurred at 75% RH for all particles. Collected ambient SSA particles were also examined. With the exception of deliquescence, they did not exhibit the same hygroscopic characteristics as the NaCl particles. The ambient particles, however, behaved most similarly to the synthesized and natural SSA particles, although the onset of morphological change was slightly higher for the S-SSA particles. We used energy-dispersive X-ray spectrometry to study the composition of the liquid layer formed on the S-SSA and N-SSA particles. The layer was enriched in Mg, S, and O relative to the solid particle core. An important implication of these results is that MgSO4-enriched solutions on the surface of SSA particles may be the solvents of many heterogeneous reactions

Trajectories of exposure and vulnerability of small islands to climate change

The authors thank the funding and logistical supports for the Back to the Future workshop (France, October 8–10, 2013) provided by the Corderie Royale de Rochefort, the Regional Council of Poitou-Charentes, the Conservatoire du Littoral, the Fondation de France, the Club Méditerranée, the Communautés d'agglomération de La Rochelle et du Pays Rochefortais, and the Université populaire du Littoral Charentais 17 and the French National Research Agency (CapAdapt project, ANR-2011-JSH1-004 01 and STORISK project, ANR-15-CE03-0003).This article advocates for a dynamic and comprehensive understanding of vulnerability to climate-related environmental changes in order to feed the design of adaptation future pathways. It uses the trajectory of exposure and vulnerability (TEV) approach that it defines as ‘storylines of driving factors and processes that have influenced past and present territorial system exposure and vulnerability to impacts associated with climate variability and change.’ The study is based on the analysis of six peer-reviewed Pacific island case studies covering various geographical settings (high islands vs low-lying reef islands, urban vs rural) and hazards associated with climate variability and change; that addressed the interactions between natural and anthropogenic driving factors; and adopted multidecadal past-to-present approaches. The findings emphasize that most urban and rural reef and high islands have undergone increasing exposure and vulnerability as a result of major changes in settlement and demographic patterns, lifestyles and economies, natural resources availability, and environmental conditions. The article highlights three generic and successive periods of change in the studied islands’ TEV: from geopolitical and political over the colonization-to-political independence period; to demographic, socio-economic, and cultural from the 1960s to the 1980s; culminating in the dominance of demographic, socio-economic, cultural, and environmental drivers since the 1980s. Based on these empirical insights, the article emphasizes the existence of anthropogenic-driven path-dependency effects in TEV, thus arguing for the analysis of the temporal dimensions of exposure and vulnerability to be a prerequisite for science to be able to inform policy- and decision-making processes toward robust adaptation pathways.PostprintPeer reviewe

WISE/NEOWISE Observations of Comet 103P/Hartley 2

We report results based on mid-infrared photometry of comet 103P/Hartley 2 taken during 2010 May 4-13 (when the comet was at a heliocentric distance of 2.3 AU, and an observer distance of 2.0 AU) by the Wide-field Infrared Survey Explorer. Photometry of the coma at 22 μm and data from the University of Hawaii 2.2 m telescope obtained on 2010 May 22 provide constraints on the dust particle size distribution, d log n/d log m, yielding power-law slope values of alpha = –0.97 ± 0.10, steeper than that found for the inbound particle fluence during the Stardust encounter of comet 81P/Wild 2. The extracted nucleus signal at 12 μm is consistent with a body of average spherical radius of 0.6 ± 0.2 km (one standard deviation), assuming a beaming parameter of 1.2. The 4.6 μm band signal in excess of dust and nucleus reflected and thermal contributions may be attributed to carbon monoxide or carbon dioxide emission lines and provides limits and estimates of species production. Derived carbon dioxide coma production rates are 3.5(± 0.9) × 10^(24) molecules per second. Analyses of the trail signal present in the stacked image with an effective exposure time of 158.4 s yields optical-depth values near 9 × 10^(–10) at a delta mean anomaly of 0.2 deg trailing the comet nucleus, in both 12 and 22 μm bands. A minimum chi-squared analysis of the dust trail position yields a beta-parameter value of 1.0 × 10^(–4), consistent with a derived mean trail-grain diameter of 1.1/ρ cm for grains of ρ g cm^(–3) density. This leads to a total detected trail mass of at least 4 × 10^(10) ρ kg