REDD and Clean Technologies Innovations: Is There a Trade-Off?
A key policy question when discussing REDD is how to balance low-cost forestry emission reductions, available in the near term, with investments to drive technological innovation in energy, industry, and other sectors over the longer period. In this article we report a research effort showing that the link of REDD to an international carbon market is, as expected, economically efficient. In addition, provided that the climate policy is stringent (we explore here a 535 ppmv CO2e concentration target), the cost savings due to REDD should entail only a modest tradeoff in terms of reduced clean energy innovation. Reduced clean energy innovation could in principle handicap future efforts to reduce global emissions. However, this analysis suggests that the availability of REDD, in particular when combined with the possibility of banking emission allowances, could provide a head start on climate mitigation that is an aggregate hedge against uncertain future costs. Integrating REDD into global carbon markets could thus lower policy costs and facilitate more ambitious climate policies now and in the future.
Reducing carbon emissions from deforestation and forest degradation: issues for policy design and implementation
There is a new international policy focus on reducing emissions from deforestation and forest degradation (REDD), as well as promoting forest conservation, the sustainable management of forests and the enhancement of forest carbon stocks (REDD-plus). The recent Conference of Parties meeting of 196 countries of the United Nations Framework Convention on Climate Change (UNFCCC) in Cancun, Mexico (December 2010) was able to advance initiatives on REDD-plus even while there was limited progress on fossil fuel related aspects of an international climate change agreement. The Cancun meeting recognised that there was strong and broad support for REDD-plus and was able to agree to the development of a formal Mechanism under the UNFCCC for incentivizing REDD-plus activities. Implementing the Mechanism is another matter, and will require the development and coordination of country REDD-plus readiness and financing, including detailed consideration of country reference levels, measurement, reporting and verification methodologies, and sub-national and national program coordination.
Thermal incompatibility analysis of metal-ceramic systems based on flexural displacement data.
The feasibility of simple tests or analytical methods for prediction of residual stress states in metal-ceramic (MC) prostheses has not been demonstrated. Biomaterial metal-ceramic strips have been proposed to provide sensitive measures of transient and residual stress states through the measurement of midpoint deflection after cooling from the ceramic sintering temperature. The objective of this study was to apply the elastic-viscoelastic analogy to calculate transient and residual midpoint deflections in MC biomaterial strips and to compare these values with deflections measured with a beam-bending viscometer (BBV). Calculations and measurements were made for five MC systems that were found from a clinical study to be "thermally compatible" systems. Metal strips, 64 mm in length, 3 mm wide, and either 0.5 mm, 1.0 mm, or 2.0 mm in thickness, were veneered with four 0.25-mm thick layers of opaque porcelain. Midpoint deflection of the MC strips (ceramic oriented in the posterior position) was measured during cooling from an initial temperature of 700 degrees C. In general, the directions of the measured residual deflections did not agree with the "textbook" convention that negative deflections are associated with positive thermal contraction mismatch (alpha(M) - alpha(c) > 0) regardless of metal thickness. For a metal thickness of 0.5 mm, the residual midpoint deflection for all thermal contraction mismatch cases, except one, was positive (upward deflection) whereas the residual midpoint deflections were all negative when the metal thickness was increased to 1 or 2 mm, independent of the thermal contraction mismatch. The best agreement between calculated and measured values of residual midpoint deflection (+16 microns vs. +14 +/- 2.3 microns, respectively was obtained for MC biomaterial strips with a Ni-Cr alloy (0.5 mm thick) while the largest difference (+346 microns vs. +61 +/- 43.8 microns) was obtained for MC bimaterial strips with a Au-Pd allow (0.5 mm thick). In all but one case, changes in deflection direction as a function of metal thickness were correctly predicted by the viscoelastic analysis. The results of this study indicate that a viscoelastic model is useful for estimating thermal compatibility conditions of MC systems.