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Systemic trade risk of critical resources
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Complex Systems: In the wake of the 2008 financial crisis, the role of strongly interconnected markets in causing systemic instability has been increasingly acknowledged. Trade networks of commodities are susceptible to cascades of supply shocks that increase systemic trade risks and pose a threat to geopolitical stability. We show that supply risk, scarcity, and price volatility of nonfuel mineral resources are intricately connected with the structure of the worldwide trade networks spanned by these resources. At the global level, we demonstrate that the scarcity of a resource is closely related to the susceptibility of the trade network with respect to cascading shocks. At the regional level, we find that, to some extent, region-specific price volatility and supply risk can be understood by centrality measures that capture systemic trade risk. The resources associated with the highest systemic trade risk indicators are often those that are produced as by- products of major metals. We identify significant strategic shortcomings in the management of systemic trade risk, in particular in the European Union.
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Biotic and Human Vulnerability to Projected Changes in Ocean Biogeochemistry over the 21st Century
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Ongoing greenhouse gas emissions can modify climate processes and induce shifts in ocean temperature, pH, oxygen concentration, and productivity, which in turn could alter biological and social systems. Here, we provide a synoptic global assessment of the simultaneous changes in future ocean biogeochemical variables over marine biota and their broader implications for people. We analyzed modern Earth System Models forced by greenhouse gas concentration pathways until 2100 and showed that the entire world’s ocean surface will be simultaneously impacted by varying intensities of ocean warming, acidification, oxygen depletion, or shortfalls in productivity. In contrast, only a small fraction of the world’s ocean surface, mostly in polar regions, will experience increased oxygenation and productivity, while almost nowhere will there be ocean cooling or pH elevation. We compiled the global distribution of 32 marine habitats and biodiversity hotspots and found that they would all experience simultaneous exposure to changes in multiple biogeochemical variables. This superposition highlights the high risk for synergistic ecosystem responses, the suite of physiological adaptations needed to cope with future climate change, and the potential for reorganization of global biodiversity patterns. If co-occurring biogeochemical changes influence the delivery of ocean goods and services, then they could also have a considerable effect on human welfare. Approximately 470 to 870 million of the poorest people in the world rely heavily on the ocean for food, jobs, and revenues and live in countries that will be most affected by simultaneous changes in ocean biogeochemistry. These results highlight the high risk of degradation of marine ecosystems and associated human hardship expected in a future following current trends in anthropogenic greenhouse gas emissions.
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Habitat fragmentation and its lasting impact on Earth’s ecosystems
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We conducted an analysis of global forest cover to reveal that 70% of remaining forest is within 1 km of the forest’s edge, subject to the degrading effects of fragmentation. A synthesis of fragmentation experiments spanning multiple biomes and scales, five continents, and 35 years demonstrates that habitat fragmentation reduces biodiversity by 13 to 75% and impairs key ecosystem functions by decreasing biomass and altering nutrient cycles. Effects are greatest in the smallest and most isolated fragments, and they magnify with the passage of time. These findings indicate an urgent need for conservation and restoration measures to improve landscape connectivity, which will reduce extinction rates and help maintain ecosystem services.
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Planetary boundaries: Guiding human development on a changing planet
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The planetary boundaries framework defines a safe operating space for humanity based on the intrinsic biophysical processes that regulate the stability of the Earth System. Here, we revise and update the planetary boundaries framework, with a focus on the underpinning biophysical science, based on targeted input from expert research communities and on more general scientific advances over the past 5 years. Several of the boundaries now have a two-tier approach, reflecting the importance of cross-scale interactions and the regional-level heterogeneity of the processes that underpin the boundaries. Two core boundaries—climate change and biosphere integrity—have been identified, each of which has the potential on its own to drive the Earth System into a new state should they be substantially and persistently transgressed.
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The declining uptake rate of atmospheric CO2 by land and ocean sinks
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Through 1959–2012, an airborne fraction (AF) of 0.44 of total anthropogenic CO2 emissions remained in the atmosphere, with the rest being taken up by land and ocean CO2 sinks. Understanding of this uptake is critical because it greatly alleviates the emissions reductions required for climate mitigation, and also reduces the risks and damages that adaptation has to embrace. An observable quantity that reflects sink properties more directly than the AF is the CO2 sink rate (kS), the combined land–ocean CO2 sink flux per unit excess atmospheric CO2 above preindustrial levels. Here we show from observations that kS declined over 1959–2012 by a factor of about 1/3, implying that CO2 sinks increased more slowly than excess CO2. Us- ing a carbon–climate model, we attribute the decline in kS to four mechanisms: slower-than-exponential CO2 emissions growth (∼ 35 % of the trend), volcanic eruptions (∼ 25 %), sink responses to climate change (∼ 20 %), and nonlinear responses to increasing CO2, mainly oceanic (∼ 20 %). The first of these mechanisms is associated purely with the trajectory of extrinsic forcing, and the last two with intrinsic, feedback responses of sink processes to changes in climate and atmospheric CO2. Our results suggest that the effects of these intrinsic, nonlinear responses are already detectable in the global carbon cycle. Although continuing future decreases in kS will occur under all plausible CO2 emission scenarios, the rate of decline varies between scenarios in non- intuitive ways because extrinsic and intrinsic mechanisms respond in opposite ways to changes in emissions: extrinsic mechanisms cause kS to decline more strongly with increasing mitigation, while intrinsic mechanisms cause kS to decline more strongly under high-emission, low-mitigation scenarios as the carbon–climate system is perturbed further from a near-linear regime.
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Scaling up from gardens: biodiversity conservation in urban environments
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As urbanisation increases globally and the natural environment becomes increasingly fragmented, the importance of urban green spaces for biodiversity conservation grows. In many countries, private gardens are a major component of urban green space and can provide considerable biodiversity benefits. Gardens and adjacent habitats form interconnected networks and a landscape ecology framework is necessary to understand the relationship between the spatial configuration of garden patches and their constituent biodiversity. A scale-dependent tension is apparent in garden management, whereby the individual garden is much smaller than the unit of management needed to retain viable populations. To overcome this, here we suggest mechanisms for encouraging ‘wildlife-friendly’ management of collections of gardens across scales from the neighbourhood to the city.
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Conservation Easements and Climate Change
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The current law of conservation easements does not recognize the full potential for carbon capture.
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CONSERVATION EASEMENTS AT THE CLIMATE CHANGE CROSSROADS
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This article examines the conundrum that occurs when climate change leads to a landscape that conflicts with conservation easement terms. In facing the challenge of a disconnect between conservation easements and a changing world, there are two main tacks. First, conservationists can make conservation easements fit the changing landscape. Second, conservationists can change the landscape to fit the conservation easements. Both of these options present challenges and conflict with the essence of the conservation easement tool. A conservation easement that is too changeable endangers the perpetual protection that is the cornerstone of conservation easements. But, forcing the landscape to fit a conservation easement requires active management, something more often associated with fee-simple ownership. The solution to using conservation easements in a changing world lies somewhere between these two extremes, with the most important level of analysis being an assessment of when to use conservation easements.
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Conservation easements and global climate change
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Land conservation is necessary to combat the ills of climate change and environmental degradation. The warming of the climate system is unequivocal. The Intergovernmental Panel on Climate Change (IPCC) recently released an updated report regarding the existence and impacts of global climate change. The report noted that the “resilience of many ecosystems is likely to be exceeded this century by an unprecedented combination of climate change, associated disturbances (e.g., flooding, drought, wildfire, insects, ocean acidification) and other global climate change drivers (e.g., land use change, pollution,fragmentation of natural systems, overexploitation of resources).”
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The Use of Conservation Easements in Adapting Conservation to a Changing Climate
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Rally 2009: The National Land Conservation Conference Portland, Oregon
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