Publication year: 2011
Source: Current Opinion in Environmental Sustainability, Available online 8 September 2011

Jan Willem Erisman, Jim Galloway, Sybil Seitzinger, Albert Bleeker, Klaus Butterbach-Bahl

Humans have doubled levels of reactive nitrogen in circulation, largely as a result of fertilizer application and fossil fuel burning. This massive alteration of the nitrogen cycle affects climate, food security, energy security, human health and ecosystem services. Our estimates show that nitrogen currently leads to a net-cooling effect on climate with very high uncertainty. The many complex warming and cooling interactions between nitrogen and climate need to be better assessed, taking also into account the other effects of nitrogen on human health, environment and ecosystem services. Through improved nitrogen management substantial reductions in atmospheric greenhouse gas concentrations could be generated, also allowing for other co-benefits, including improving human health and improved provision of ecosystem services, for example clean air and water, and biodiversity.

Highlights

► Humans have doubled levels of reactive nitrogen in circulation, largely as a result of fertilizer application and fossil fuel burning. ► Initial quantifications of the effect of Nron climate show that there is a small net cooling effect of −0.24 W m, with high uncertainty. ► The many complex warming and cooling interactions between nitrogen and climate need to be better assessed. ► Policies should be focused to both reduce effects on climate and environmental and human health impacts. ► This requires an integral and multi-disciplinary approach including: multi-source/actor, multi-pollutant, multi-problem, multi-benefits, multi-receptor, multi-effect, multi-scales, etc.

Publication year: 2011
Source: Current Opinion in Environmental Sustainability, Volume 3, Issue 4, September 2011, Pages 260-264

Douglas F Barnes

Countries embarking on providing electricity to their poorest populations face significant challenges. One is deciding how to create or modify existing institutions and policies to support rural electrification initiatives. Existing electricity companies often have a tradition of serving mostly urban populations and thus may be reluctant to support rural electrification programs. Scaling up electricity access in rural areas may require creating independent institutions or setting up special programs within electricity companies. Complementary solutions, involving both grid and offgrid approaches, may be needed. Grid extension should be pursued as a least-cost option in more densely populated and economically advanced areas, where power demand and load densities are high []. Where grid extension is not least-cost or reaching remote communities through grid network expansion is economically impractical, offgrid technologies and business models involving renewable energy or even small diesel systems should be adopted to provide basic levels of electricity service.

Highlights

â–º Approximately 1.4 billion people across the globe still lack access to electricity. â–º Countries embarking on providing electricity to their poorest populations face several challenges including the development of institutional models, choice of appropriate technologies, and finding ways of implementation that are financially viable. â–º Successful programs from around the world illustrate that principles and not prescriptions are most important for implementing sustainable rural electrification.

Publication year: 2011
Source: Current Opinion in Environmental Sustainability, Available online 8 September 2011

Jenny Farmer, Robin Matthews, Jo U Smith, Pete Smith, Brajesh K Singh

Modelling greenhouse gas (GHG) emissions from tropical peatlands is of crucial importance in determining GHG emission rates under global change. Modelling efforts to date have been restricted by the lack of available data for parameterisation, input and validation of simulation models, due to the complex and often inaccessible nature of tropical peatland ecosystems. There have been very limited experimental or modelling studies to predict GHG fluxes from tropical peatlands. However, our understanding of temperate and boreal peatlands is much more advanced. In this paper we consider the processes that would need to be taken into account in modelling tropical peatlands subject to land use change, and discuss how progress in modelling on temperate peatlands could be applied to these systems.

Highlights

â–º There is currently no single model suitable for application to tropical peatlands. â–º There are models which have been used in temperate zones that could be adapted. â–º Temperate models need to be appropriately parameterised for tropical peatlands. â–º The limitation for modelling in tropical peatlands is the lack of available data. â–º Satellite imagery developments should be linked to the models being developed.

Publication year: 2011
Source: Current Opinion in Environmental Sustainability, Volume 3, Issue 4, September 2011, Pages 235-240

Shonali Pachauri

Recent international events point to a growing momentum to adopt a universal energy access target or goal. However, without an agreement about standards for measuring access from an operational point of view and consensus about the conceptual definition of access, setting such an energy access target and, more importantly, the adoption of such a target by the international community will be challenging. Previous approaches to defining access to modern energy have tended to focus on single dimensions of the access issue, such as physical supply or availability of energy carriers, adequacy (availability above a minimum threshold quantity) and affordability. To reach a consensus on defining access will require focus on three elements. First, defining what energy services should be included in the basic needs basket. Second, setting what quantitative and qualitative thresholds define minimum need. And finally, assessing how the new modern energy costs compares to existing household energy expenditures for different household income groups.

Highlights

â–º The paper reviews approaches for defining access to modern energy. â–º Previous approaches have focused on single dimensions of the access issue. â–º To reach a consensus on defining access requires focus on three elements. â–º First, what energy services should be included in the basic needs basket. â–º Second, what quantitative and qualitative thresholds define minimum needs. â–º Last, how new modern energy costs compare to existing energy expenditures.