The DICER Model: Methodological Issues and Initial Results

This paper introduces DICER, a model for the integrated assessment of climate – economy interactions within an optimal growth framework developed based on the structure of the DICE2007 model. We present the methodological differences introduced so far in DICER and some preliminary results of its deterministic version. We observe interesting results in comparison to other IAMs, such as (i) lower peak temperatures; (ii) radiative forcing differences; (iii) differences in control rates; and (iv) sensitivity of results to parameters such as climate sensitivity. A further innovation of this work has been to account for uncertainty and risk through an application of option pricing. The method allows for a simple representation of the risks through measures of volatility in the damages and abatement costs and shows that taking these factors into account lowers maximum mean temperatures by about 0.5oC. We also present some methodological issues that need to be dealt with in the near future in DICER.Climate change, Integrated Impact Assessment Model (IAM), damage function

The DICER Model: Methodological Issues and Initial Results

31 p.This paper introduces DICER, a model for the integrated assessment of climate – economy interactions within an optimal growth framework developed based on the structure of the DICE2007 model. We present the methodological differences introduced so far in DICER and some preliminary results of its deterministic version. We observe interesting results in comparison to other IAMs, such as (i) lower peak temperatures; (ii) radiative forcing differences; (iii) differences in control rates; and (iv) sensitivity of results to parameters such as climate sensitivity. A further innovation of this work has been to account for uncertainty and risk through an application of option pricing. The method allows for a simple representation of the risks through measures of volatility in the damages and abatement costs and shows that taking these factors into account lowers maximum mean temperatures by about 0.5oC. We also present some methodological issues that need to be dealt with in the near future in DICER

Regional IAM: analysis of risk-adjusted costs and benefits of climate policies

23 p.Across the full range of publications in the field of economics of climate change there is perhaps only one firm agreement: both costs and benefits of climate policy are highly uncertain. In an ideal world one would wait until a good deal of uncertainty is resolved and then make a final decision. Usually in the economic literature it would be interpreted as adopting a relatively weak policy now and adjusting it later. Unfortunately, in the context of path-dependency and irreversibility of climatic events there is no way to preserve a full flexibility for the future: near-term selection of an interim climate policy implies some irreversible consequences. Continued accumulation of GHG in the atmosphere makes some policy targets (expressed in temperature level or GHG ppm concentration) infeasible. The paper examines the application of real option analysis to calculate costs and benefits of an interim climate policy. In contrast to conventional CBA, the proposed methodology also accounts for lost and gained flexibility attributed to the adoption of an interim target

Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

Decarbonizing Russia: Leapfrogging from Fossil Fuel to Hydrogen

We examine a different approach to complete the decarbonization of the Russian economy in a world where climate policy increasingly requires the radical reduction of emissions wherever possible. We propose an energy system that can supply solar and wind-generated electricity to fulfill demand and which accounts for intermittency problems. This is instead of the common approach of planning for expensive carbon capture and storage, and a massive increase in energy efficiency and, therefore, a drastic reduction in energy use per unit of Gross Domestic Product (GDP). Coupled with this massive increase in alternative energy, we also propose using excess electricity to generate green hydrogen. Hydrogen technology can function as storage for future electricity needs or for potential fuel use. Importantly, green hydrogen can potentially be used as a replacement export for Russia’s current fossil fuel exports. The analysis was carried out using the highly detailed modeling framework, the High-Resolution Renewable Energy System for Russia (HIRES-RUS) representative energy system. The modeling showed that there are a number of feasible combinations of wind and solar power generation coupled with green hydrogen production to achieve 100% decarbonization of the Russian economy

The DICER Model: Methodological Issues and Initial Results

31 p.This paper introduces DICER, a model for the integrated assessment of climate – economy interactions within an optimal growth framework developed based on the structure of the DICE2007 model. We present the methodological differences introduced so far in DICER and some preliminary results of its deterministic version. We observe interesting results in comparison to other IAMs, such as (i) lower peak temperatures; (ii) radiative forcing differences; (iii) differences in control rates; and (iv) sensitivity of results to parameters such as climate sensitivity. A further innovation of this work has been to account for uncertainty and risk through an application of option pricing. The method allows for a simple representation of the risks through measures of volatility in the damages and abatement costs and shows that taking these factors into account lowers maximum mean temperatures by about 0.5oC. We also present some methodological issues that need to be dealt with in the near future in DICER

Regional IAM: analysis of risk-adjusted costs and benefits of climate policies

23 p.Across the full range of publications in the field of economics of climate change there is perhaps only one firm agreement: both costs and benefits of climate policy are highly uncertain. In an ideal world one would wait until a good deal of uncertainty is resolved and then make a final decision. Usually in the economic literature it would be interpreted as adopting a relatively weak policy now and adjusting it later. Unfortunately, in the context of path-dependency and irreversibility of climatic events there is no way to preserve a full flexibility for the future: near-term selection of an interim climate policy implies some irreversible consequences. Continued accumulation of GHG in the atmosphere makes some policy targets (expressed in temperature level or GHG ppm concentration) infeasible. The paper examines the application of real option analysis to calculate costs and benefits of an interim climate policy. In contrast to conventional CBA, the proposed methodology also accounts for lost and gained flexibility attributed to the adoption of an interim target

Association between night-time surgery and occurrence of intraoperative adverse events and postoperative pulmonary complications

Background: The aim of this post hoc analysis of a large cohort study was to evaluate the association between night-time surgery and the occurrence of intraoperative adverse events (AEs) and postoperative pulmonary complications (PPCs). Methods: LAS VEGAS (Local Assessment of Ventilatory Management During General Anesthesia for Surgery) was a prospective international 1-week study that enrolled adult patients undergoing surgical procedures with general anaesthesia and mechanical ventilation in 146 hospitals across 29 countries. Surgeries were defined as occurring during 'daytime' when induction of anaesthesia was between 8: 00 AM and 7: 59 PM, and as 'night-time' when induction was between 8: 00 PM and 7: 59 AM. Results: Of 9861 included patients, 555 (5.6%) underwent surgery during night-time. The proportion of patients who developed intraoperative AEs was higher during night-time surgery in unmatched (43.6% vs 34.1%; P<0.001) and propensity-matched analyses (43.7% vs 36.8%; P = 0.029). PPCs also occurred more often in patients who underwent night-time surgery (14% vs 10%; P = 0.004) in an unmatched cohort analysis, although not in a propensity-matched analysis (13.8% vs 11.8%; P = 0.39). In a multivariable regression model, including patient characteristics and types of surgery and anaesthesia, night-time surgery was independently associated with a higher incidence of intraoperative AEs (odds ratio: 1.44; 95% confidence interval: 1.09-1.90; P = 0.01), but not with a higher incidence of PPCs (odds ratio: 1.32; 95% confidence interval: 0.89-1.90; P = 0.15). Conclusions: Intraoperative adverse events and postoperative pulmonary complications occurred more often in patients undergoing night-time surgery. Imbalances in patients' clinical characteristics, types of surgery, and intraoperative management at night-time partially explained the higher incidence of postoperative pulmonary complications, but not the higher incidence of adverse events