Consumption-based carbon accounting: does it have a future?

Internationally, allocation of responsibility for reducing greenhouse gas emissions is currently based on the production-based (PB) accounting method, which measures emissions generated in the place where goods and services are produced. However, the growth of emissions embodied in trade has raised the question whether we should switch to, or amalgamate PB accounting, with other accounting approaches. Consumption-based (CB) accounting has so far emerged as the most prominent alternative. This approach accounts for emissions at the point of consumption, attributing all the emissions that occurred in the course of production and distribution to the final consumers of goods and services. This review has a fourfold objective. First, it provides an account of the logic behind attributing responsibility for emissions on the basis of consumption instead of production. Issues of equity and justice, increased emissions coverage, encouragement of cleaner production practices, and political benefits are considered. Second, it discusses the counterarguments, focusing in particular on issues of technical complexity, mitigation effectiveness, and political acceptability. Third, it presents the spectrum of implementation possibilities—ranging from the status quo to more transformative options—and considers the implications for international climate policy that would accrue under various scenarios of adopting CB accounting in practice. Fourth, it looks at how CB accounting may be adjusted to fit with current political realities and it identifies policy mechanisms that could potentially be utilized to directly or indirectly address CB emissions. Such an approach could unlock new opportunities for climate policy innovation and for climate mitigation

Comparison of lipase production by Geotrichum candidum in stirring and airlift fermenters

The production of lipase by Geotrichum candidum in both, stirred tank and airlift bioreactors were compared. G candidum an imperfect filamentous fungus, grows well in liquid medium, and produces a lipase with specific affinity for long-chain fatty acids with cis-9 double bonds but, lipase production is generally not efficient because the optimum medium composition and fermentation conditions are not known. Response surface methodology was used to optimize the agitation speed (100-500 rpm) and aeration (0.2-1.8 vvm) for production of lipase by G candidum in a bench-scale stirred fermenter. A Central Composite Rotatable Design (CCRD) was used to optimize lipase activity and productivity. Lipase production in an airlift fermenter was also studied with aeration ranging from I to 3 vvm. A previously optimized culture medium containing 3.58% of peptone, 0.64% of soy oil and an initial pH of 7.0, was used in the experiments, incubating at 30 degreesC. In the stirred reactor the optimum conditions of agitation and aeration for lipase production and productivity were 300 rpm and 1 vvm, leading to an activity of 20 U cm(-1) in 54 h of fermentation and 0.3900 (U cm(-3) h(-1)) of productivity. The best aeration condition in the airlift fermenter was 2.5 vvm, which yielded similar lipase activity after 30 h of fermentation, resulting in a productivity of 0.6423 (U cm(-3) h(-1)). In the absence of mechanical agitation similar lipase yields were achieved but in less time, resulting in productivity, about 60% greater than in a stirred fermenter; the lower energy demand for the same lipase yield offers economic advantages. (C) 2004 Society of Chemical Industry.801616