California recently established a carbon cap-and-trade program in the interest of improving air quality and fighting global climate change. The tax revenues generated from this program are used to fund projects that help reduce greenhouse gas (GHG) emissions, but policymakers face the challenge of deciding which projects are best suited for this funding. To inform this decision-making process, Matute and Chester (2015) compared the effectiveness of different current and future public transportation projects to determine which is the most cost-effective, in terms of public dollars spent per ton of carbon dioxide equivalent released. The study compared four projects from Los Angeles County: the Orange Bus Rapid Transport (Orange BRT) line in the San Fernando Valley, the Gold Light Rail Transport (Gold LRT) line that runs from Los Angeles to Pasadena, a bicycle and pedestrian pathway along the Orange BRT line, and the California High Speed Rail (CAHSR) project, a plan being developed to expand high-speed rail throughout the state. All four projects were found to have negative costs per ton of carbon dioxide reduced, indicating that they actually save the public money over time. For a 100-year period, the bicycle pathway was found to be most cost-effective, followed by the Gold LRT, Orange BRT, and CAHSR. Continue reading →
The main considerations in whether and where to install photovoltaic (PV) panels are how much sun there is, and how much the panels cost. Right? Not necessarily. Engineers at Arizona State University have just published a paper pointing out that if a goal of installing photovoltaics is to decrease greenhouse gas emissions, it would be prudent to consider the emissions from manufacturing—which vary significantly by panel type—how long they stay in the atmosphere, and whether or not the installation is competing with other renewable energy sources rather than with fossil fuel burning. Because of the greenhouse gases associated with manufacturing, all panel installations increase greenhouse effects in the short term, although the initial two-year effect is to reduce them owing to sulfur and nitrogen oxides released from power plants during manufacture.