Predicting δCDIC dynamics in CCS: A scheme based on a review of inorganic carbon chemistry under elevated pressures and temperatures

Stable carbon isotopes are important tools to assess potential storage sites for CO₂, as they allow the quantification of ionic trapping via isotope mass balances. In deep geological formations high p/T conditions need to be considered, because CO₂ dissolution, equilibrium constants and isotope fractionation of dissolved inorganic carbon (DIC) depend on temperature, pressure and solute composition. After reviewing different approaches to account for these dependencies, an expanded scheme is presented for speciation and carbon isotope fractionation of DIC and dissolution of CaCO₃ for pCO₂ up to 100 bar, pH down to 3 and temperatures of up to 200 °C. The scheme evaluates the influence of respective parameters on isotope ratios during CO₂ sequestration. The pCO₂ and pH are the dominant controlling factors in the DIC/δ¹³C/pH system. The fugacity of CO₂ has major impact on DIC concentrations at temperatures below 100 °C at high pCO₂. Temperature dependency of activities and equilibrium dominates at temperatures above 100 °C. Isotope ratios of DIC are expected to be about 1–2‰ more depleted in ¹³C compared to the free CO₂ at pCO₂ values above 10 bar. This depletion is controlled by carbon isotope fractionation between CO₂ and H₂CO₃* which is the dominant species of DIC at the resulting pH below 5.     

Young fire ant workers feign death and survive aggressive neighbors

Feigning death is a method of self-defense employed among a wide range of prey species when threatened by predator species. This paper reports on death-feigning behavior by the fire ant, Solenopsis invicta, during intraspecific aggression among neighboring fire ant workers. Days-old workers responded to aggression by death feigning, weeks-old workers responded by fleeing and months-old workers responded by fighting back. By feigning death, days-old workers were four times more likely to survive aggression than older workers. From a proximate perspective, retaliation by young workers against aggressive older workers is certain to fail. With their relatively soft exoskeleton, young workers would be prone to injury and death and unable to execute an effective attack of biting or stinging older workers with harder exoskeletons. From an ultimate perspective, death feigning allows young workers to survive and contribute to brood care and colony growth, both of which are essential to queen survival and fitness.     

Modification of evaluation method for auto-assessment and electronic submission by businesses

SUMMARY

This paper describes the evolution of an evaluation method developed initially to assess progress towards sustainable development for various land use activities in Costa Rica. Since that time, the method has been expanded to apply to all types of business activities in any location, and refined so that a numerical score can be provided for each attribute. These scores can then be presented graphically in four categories. The method has since been tested on a variety of businesses and is being refined for electronic submission and display of the results. The benefits of this approach, as well as its shortcomings and some of the problems resolved, are presented.     

Using boundary objects to stimulate transformational thinking: storm resilience for the Port of Providence,Rhode Island (USA)

Like many coastal ports around the world, Rhode Island’s Port of Providence in USA is at risk for climate-related natural hazards, such as catastrophic storm surges and significant sea level rise (0.5–2.0 m), over the next century. To combat such events, communities may eventually adopt so-called “transformational adaptation” strategies, like the construction of major new infrastructure, the reorganization of vulnerable systems, or changes in their locations. Such strategies can take decades or more to plan, design, find consensus around, fund, and ultimately implement. Before any meaningful decisions can be made, however, a shared understanding of risks, consequences, and options must be generated and allowed to percolate through the decision-making systems. This paper presents results from a pre-planning exercise that utilized “boundary objects” to engage the Port of Providence's stakeholders in an early dialogue about the transformational approaches to hazard–risk mitigation. The research team piloted the following three boundary objects as a means to initiate meaningful dialogue about long-term storm resilience challenges amongst key stakeholders of this exposed seaport system: (1) a storm scenario with local-scale visualizations, (2) three long-term transformational resilience concepts, and (3) a decision support tool called Wecision. The team tested these boundary objects in a workshop setting with 30 port business owners and policy makers, and found them to be an effective catalyst to generate a robust dialogue around a very challenging topic.