The potential power generation from land-based bioenergy is predicted globally using a computer model. Simultaneous consideration of land use, cost and carbon restrictions enables practical evaluation of net power output. Comparisons are made with wind and solar power, and a sensitivity analysis is used to explore the effects of different policy assumptions. Biomass is shown to offer only moderate power-generating potential, and would satisfy less than half of current demand even if all suitable existing arable land were used to grow bioenergy crops. However, bioenergy can be cheap to generate given current economics, and is able to remove atmospheric carbon in some cases if coupled with carbon capture and storage. Wind turbines are able to provide more power globally, but photovoltaic solar panels are the only source considered with the potential to satisfy existing demand. Since land-based bioenergy is also restricted by the need to grow food for an expanding population, and technological developments are likely to greatly increase the viability of other renewable sources, the role of land-based bioenergy appears relatively limited and short-term.
Abstract This paper explores the influence of spatial scale on modelled projections of soil organic carbon (SOC) content. The effect of land use change (LUC) on future SOC stocks was estimated using the Rothamsted Carbon model for a small area of southern Belgium. The study assumed no management change and used a single climate change scenario. Three model experiments were used to identify how data scale affects predicted SOC stocks: (i) using European LUC datasets at a resolution of 10′ and assuming equal distribution of change within the study area, (ii) using more accurate regional data aggregated to the 10’ resolution, and (iii) using the regional data at a spatial resolution of 250 m. The results show that using coarse resolution (10′) data is inappropriate when modelling SOC changes in the study area as only the methods using precise data predict a change in SOC stocks similar to those reported in the literature. This is largely because of differences in model parameterisation. However, precisely locating LUC does not significantly affect the results. The model, using either pan‐European or region‐specific precise data predicts an average SOC increase of 1 t C ha −1 (1990–2050), mainly resulting from afforestation of 13% of agricultural land.
Global atmospheric methane concentrations have continued to rise in recent years, having already more than doubled since the Industrial Revolution. Further environmental change, especially climate change, in the twenty-first century has the potential to radically alter global methane fluxes. Importantly, changes in temperature, precipitation, and net primary production may induce positive climate feedback effects in dominant natural methane sources such as wetlands, soils, and aquatic ecosystems. Anthropogenic methane sources may also be impacted, with a risk of enhanced emissions from the energy, agriculture, and waste sectors. Here, we review the global sources of methane, the trends in fluxes by source and sector, and their possible evolution in response to future environmental change. We discuss ongoing uncertainties in flux estimation and projection, and highlight the great potential for multisector methane mitigation as part of wider global climate change policy.
ABSTRACT Climate change threatens biodiversity, water, food and human health and well‐being. Rapid, sustained mitigation and adaptation actions can benefit all these elements of the nexus. Key transitions in energy, land and marine ecosystems, urban areas, industry and society are essential for climate change mitigation, adaptation and sustainable development. These transitions require interdisciplinary research, policy support and societal engagement. Here we present an assessment of 69 response options, a subset of which (15) was used in the climate change chapter of the IPBES Nexus Assessment. We show that the majority of climate change response options for land, oceans and ecosystems, settlement and infrastructure, industrial and societal system transitions have broadly positive impacts across the nexus. However, energy system transitions show more apparent trade‐offs. Most of these impacts result from energy infrastructure that would also be required for fossil fuel‐based systems and should be compared to the far more damaging consequences of continued fossil fuel use. Transitioning to cleaner, renewable energy sources reduces these risks and offers significant improvements across the nexus by reducing climate change impacts. Of the 69 response options assessed, 59% have entirely positive effects, or at least no negative effects, across all nexus elements and can be considered as low‐risk, immediately actionable options. The remaining 41% show either negative or variable impacts on at least one nexus element. However, this does not render them unviable; rather, their implementation must be carefully managed. Where impacts are variable, strategies should be tailored to ensure positive outcomes; where trade‐offs are unavoidable, efforts should focus on minimising negative effects and maximising synergies. Our findings suggest that prioritising policies that address the interconnected challenges of climate change, biodiversity loss, land degradation, pollution, food insecurity, access to clean water, energy for all and sustainable development will deliver more effective and equitable climate action.
Systems approaches have great potential for application in predictive ecology. In this paper, we present a range of examples, where systems approaches are being developed and applied at a range of scales in the field of global change and biogeochemical cycling. Systems approaches range from Bayesian calibration techniques at plot scale, through data assimilation methods at regional to continental scales, to multi-disciplinary numerical model applications at country to global scales. We provide examples from a range of studies and show how these approaches are being used to address current topics in global change and biogeochemical research, such as the interaction between carbon and nitrogen cycles, terrestrial carbon feedbacks to climate change and the attribution of observed global changes to various drivers of change. We examine how transferable the methods and techniques might be to other areas of ecosystem science and ecology.