Estimating the Effect of the Canadian Government's 2006-2007 Greenhouse Gas Policies

Mounting public concern about climate change has prompted the Canadian government to respond with a major policy effort to reduce greenhouse gas (GHG) emissions. Since early 2006, the Conservative government has launched a series of initiatives under its “ecoACTION” banner, culminating in the release in April 2007 of its “regulatory framework for air emissions,” which is currently under consultative review.economic growth, economic innovation

The Citizen's Guide to Climate Success

Concerned citizens can drive the energy transition needed to prevent climate change by their personal choices and their identification and support of climate-sincere politicians. Jaccard explains the simplicity and modest cost of decarbonizing electricity and transportation in developed countries and spreading that critical change worldwide

Taxing Emissions, Not Income: How to Moderate the Regional Impact of Federal Environment Policy

Canadian policymakers have the policy tools needed to ameliorate the regional economic harm that taxing GHG emissions can cause. A price on GHG emissions will affect Canadian provinces differently, possibly undermining support for a policy that incurs regional transfers of income. The authors recommend returning to the provinces the revenues collected through auctioned emissions permits, so that they may offer personal and corporate income tax relief, all to moderate the regional impact of GHG carbon policy. Allowing provinces to retain the revenues collected from auctioned emissions permits would achieve a greater degree of regional equity than the other policy options.Economic Growth and Innovation, GHG emissions, GHG carbon policy. Canadian federal policy, regional impacts of climate policy

Hybrid Modeling: New Answers to Old Challenges

After nearly two decades of debate and fundamental disagreement, topdown and bottom-up energy-economy modelers, sometimes referred to as modeling ‘tribes', began to engage in productive dialogue in the mid-1990s (IPCC 2001). From this methodological conversation have emerged modeling approaches that offer a hybrid of the two perspectives. Yet, while individual publications over the past decade have described efforts at hybrid modeling, there has not as yet been a systematic assessment of their prospects and challenges. To this end, several research teams that explore hybrid modeling held a workshop in Paris on April 20–21, 2005 to share and compare the strategies and techniques that each has applied to the development of hybrid modeling. This special issue provides the results of the workshop and of follow-up efforts between different researchers to exchange ideas.climat ; modeling

Hybrid Modeling: New Answers to Old Challenges

International audienceAfter nearly two decades of debate and fundamental disagreement, topdown and bottom-up energy-economy modelers, sometimes referred to as modeling ‘tribes', began to engage in productive dialogue in the mid-1990s (IPCC 2001). From this methodological conversation have emerged modeling approaches that offer a hybrid of the two perspectives. Yet, while individual publications over the past decade have described efforts at hybrid modeling, there has not as yet been a systematic assessment of their prospects and challenges. To this end, several research teams that explore hybrid modeling held a workshop in Paris on April 20–21, 2005 to share and compare the strategies and techniques that each has applied to the development of hybrid modeling. This special issue provides the results of the workshop and of follow-up efforts between different researchers to exchange ideas

Chromium Cycling in Redox‐Stratified Basins Challenges δ ⁵³ Cr Paleoredox Proxy Applications

Chromium stable isotope composition (δ53Cr) is a promising tracer for redox conditions throughout Earth's history; however, the geochemical controls of δ53Cr have not been assessed in modern redox-stratified basins. We present new chromium (Cr) concentration and δ53Cr data in dissolved, sinking particulate, and sediment samples from the redox-stratified Lake Cadagno (Switzerland), a modern Proterozoic ocean analog. These data demonstrate isotope fractionation during incomplete (non-quantitative) reduction and removal of Cr above the chemocline, driving isotopically light Cr accumulation in euxinic deep waters. Sediment authigenic Cr is isotopically distinct from overlying waters but comparable to average continental crust. New and published data from other redox-stratified basins show analogous patterns. This challenges assumptions from δ53Cr paleoredox applications that quantitative Cr reduction and removal limits isotope fractionation. Instead, fractionation from non-quantitative Cr removal leads to sedimentary records offset from overlying waters and not reflecting high δ53Cr from oxidative continental weathering.ISSN:0094-8276ISSN:1944-800

3D XY scaling theory of the superconducting phase transition

The intermediate 3D XY scaling theory of superconductivity at zero and nonzero magnetic fields is developed, based only upon the dimensional hypothesis $B\sim (Length)^{-2}$. Universal as well as nonuniversal aspects of the theory are identified, including background terms and demagnetization effects. Two scaling regions are predicted: an "inner" region (very near the zero field superconducting transition, $T_c$), where the fields $B$, $H$, and $H_{ex}$ differ substantially, due to the presence of diamagnetic fluctuations, and an "outer" region (away from $T_c$), where the fields can all be treated similarly. The characteristic field ($H_0$) and temperature ($t_1$) scales, separating the two regimes, are estimated. Scaling theories of the phase transition line, magnetization, specific heat, and conductivity are discussed. Multicritical behavior, involving critical glass fluctuations, is investigated along the transition line, $T_m(B)$, at nonzero fields.Comment: 9 pages LaTeX, 1 .eps figure, version accepted for publicatio

HIV Risk Behavior Self-Report Reliability at Different Recall Periods

Few studies have investigated the optimal length of recall period for self-report of sex and drug-use behaviors. This meta-analysis of 28 studies examined the test-retest reliability of three commonly used recall periods: 1, 3, and 6 months. All three recall periods demonstrated acceptable test-retest reliability, with the exception of recall of needle sharing behaviors and 6-months recall of some sex behaviors. For most sex behaviors, a recall period of 3 months was found to produce the most reliable data; however, 6 months was best for recalling number of sex partners. Overall, shorter periods were found to be more reliable for recall of drug-use behaviors, though the most reliable length of recall period varied for different types of drugs. Implications of the findings and future directions for research are discussed