Sensitivity of the Northern Hemisphere blocking frequency to the detection index

This work has been supported in part by the European Commission in the framework of the Environment and Climate Research Programme (MERCURE, ENV4-CT97-0485 for FJDR) and by the Spanish CICYT CLI97-0558 grant

The assessment of the impact of aviation NOx on ozone and other radiative forcing responses - The importance of representing cruise altitudes accurately

Aviation emissions of NOx result in the formation of tropospheric ozone (warming) and destruction of a small amount of methane (cooling), positive and negative radiative forcing effects. In addition, the reduction of methane results in a small long-term reduction in tropospheric ozone (cooling) and, in addition, a long-term reduction in water vapour in the stratosphere (cooling) from reduced oxidation of methane, both negative radiative forcing impacts. Taking all these radiative effects together, aircraft NOx is still thought to result in a positive (warming) radiative effect under constant emissions assumptions. Previously, comparative modelling studies have focussed on the variability between models, using the same emissions database. In this study, we rather quantify the variability and uncertainty arising from different estimations of present-day aircraft NOx emissions. Six different aircraft NOx emissions inventories were used in the global chemical transport model, MOZART v3. The inventories were normalized to give the same global emission of NOx in order to remove one element of uncertainty. Emissions differed in the normalized cases by 23% at cruise altitudes (283–200 hPa, where the bulk of emission occurs, globally). However, the resultant short-term ozone chemical perturbation varied by 15% between the different inventories. Once all the effects that give rise to positive and negative radiative impacts were accounted for, the variability of net radiative forcing impacts was 94%. Using these radiative effects to formulate a net aviation NOx Global Warming Potential (GWP) for a 100-year time horizon resulted in GWPs ranging from 60 to 4, over an order of magnitude. It is concluded that the detailed placement of emissions at chemically sensitive cruise altitudes strongly affects the assessment of the total radiative impact, introducing a hitherto previously unidentified large fraction of the uncertainty of impacts between different modelling assessments. It is recommended that future formulations of aircraft NOx emissions focus efforts on the detailed and accurate placement of emissions at cruise altitudes to reduce the uncertainty in future assessments of aviation NOx impacts

Greater fuel efficiency is potentially preferable to reducing NOx emissions for aviation’s climate impacts

Aviation emissions of nitrogen oxides (NOx) alter the composition of the atmosphere, perturbing the greenhouse gases ozone and methane, resulting in positive and negative radiative forcing effects, respectively. In 1981, the International Civil Aviation Organization adopted a first certification standard for the regulation of aircraft engine NOx emissions with subsequent increases in stringency in 1992, 1998, 2004 and 2010 to offset the growth of the environmental impact of air transport, the main motivation being to improve local air quality with the assumed co-benefit of reducing NOx emissions at altitude and therefore their climate impacts. Increased stringency is an ongoing topic of discussion and more stringent standards are usually associated with their beneficial environmental impact. Here we show that this is not necessarily the right direction with respect to reducing the climate impacts of aviation (as opposed to local air quality impacts) because of the tradeoff effects between reducing NOx emissions and increased fuel usage, along with a revised understanding of the radiative forcing effects of methane. Moreover, the predicted lower surface air pollution levels in the future will be beneficial for reducing the climate impact of aviation NOx emissions. Thus, further efforts leading to greater fuel efficiency, and therefore lower CO2 emissions, may be preferable to reducing NOx emissions in terms of aviation’s climate impacts

Measuring the population burden of injuries-implications for global and national estimates: A multicentre prospective UK longitudinal study

Current methods of measuring the population burden of injuries rely on many assumptions and limited data available to the global burden of diseases (GBD) studies. The aim of this study was to compare the population burden of injuries using different approaches from the UK Burden of Injury (UKBOI) and GBD studies.The UKBOI was a prospective cohort of 1,517 injured individuals that collected patient-reported outcomes. Extrapolated outcome data were combined with multiple sources of morbidity and mortality data to derive population metrics of the burden of injury in the UK. Participants were injured patients recruited from hospitals in four UK cities and towns: Swansea, Nottingham, Bristol, and Guildford, between September 2005 and April 2007. Patient-reported changes in quality of life using the EQ-5D at baseline, 1, 4, and 12 months after injury provided disability weights used to calculate the years lived with disability (YLDs) component of disability adjusted life years (DALYs). DALYs were calculated for the UK and extrapolated to global estimates using both UKBOI and GBD disability weights. Estimated numbers (and rates per 100,000) for UK population extrapolations were 750,999 (1,240) for hospital admissions, 7,982,947 (13,339) for emergency department (ED) attendances, and 22,185 (36.8) for injury-related deaths in 2005. Nonadmitted ED-treated injuries accounted for 67% of YLDs. Estimates for UK DALYs amounted to 1,771,486 (82% due to YLDs), compared with 669,822 (52% due to YLDs) using the GBD approach. Extrapolating patient-derived disability weights to GBD estimates would increase injury-related DALYs 2.6-fold.The use of disability weights derived from patient experiences combined with additional morbidity data on ED-treated patients and inpatients suggests that the absolute burden of injury is higher than previously estimated. These findings have substantial implications for improving measurement of the national and global burden of injury

Philippines–China Relations: Interplay Between Domestic Politics and Globalization

This chapter illustrates how Philippines–China relations in the past two decades have been shaped by Philippine domestic politics and regional and global market forces. Philippine domestic politics—characterized as being personalistic, weak in institutions, and patronage-based, plus the lack of a coherent China policy—have contributed to the fluctuations in the Philippine diplomatic relations with China. Relations have also been affected by negative perceptions of China by the Filipinos—the effect of US alliance, anti-Communist ideology influence of Taiwan, and presently, China’s claim of islands in the South China Sea. Investments, loans and ODAs from China are very much affected by the health of the bilateral relations. However, bilateral trade and non-state-to-state investments are determined by external economic phenomena such as the impact of global supply network in the 1990s and 2000s, Global Financial Crisis in 2008–2009, and China’s economic rebalancing after the GFC, and more recently, China’s OBOR and AIIB initiatives. The paper also shows that, in the past few decades, Philippine’s outbound investments have shifted from China to ASEAN, which is aligned more with economic rather than political motivations, aligning with the Duterte administration’s aims to diversify its foreign engagements beyond the traditional partners