COVID-19 Implications for Scenarios and Modelling and Considerations Moving Forward: Perspectives from the Integrated Assessment Modelling Community

Presentation given at the informal virtual meeting hosted by the SBSTA Chair with representatives from the research and systematic observation community and UNFCCC constituted bodies.The event aimed to provide an opportunity for discussing the impact of the COVID-19 crisis on climate research and systematic observation, new opportunities emerging from this crisis for recovering better and what has changed and what needs to change in scientific communication on climate change

Active and passive multispectral scanner for earth resources applications: An advanced applications flight experiment

The development of an experimental airborne multispectral scanner to provide both active (laser illuminated) and passive (solar illuminated) data from a commonly registered surface scene is discussed. The system was constructed according to specifications derived in an initial programs design study. The system was installed in an aircraft and test flown to produce illustrative active and passive multi-spectral imagery. However, data was not collected nor analyzed for any specific application

Sensitivity of projected long-term CO 2 emissions across the Shared Socioeconomic Pathways

Scenarios showing future greenhouse gas emissions are needed to estimate climate impacts and the mitigation efforts required for climate stabilization. Recently, the Shared Socioeconomic Pathways (SSPs) have been introduced to describe alternative social, economic and technical narratives, spanning a wide range of plausible futures in terms of challenges to mitigation and adaptation. Thus far the key drivers of the uncertainty in emissions projections have not been robustly disentangled. Here we assess the sensitivities of future CO 2 emissions to key drivers characterizing the SSPs. We use six state-of-the-art integrated assessment models with different structural characteristics, and study the impact of five families of parameters, related to population, income, energy efficiency, fossil fuel availability, and low-carbon energy technology development. A recently developed sensitivity analysis algorithm allows us to parsimoniously compute both the direct and interaction effects of each of these drivers on cumulative emissions. The study reveals that the SSP assumptions about energy intensity and economic growth are the most important determinants of future CO 2 emissions from energy combustion, both with and without a climate policy. Interaction terms between parameters are shown to be important determinants of the total sensitivities

Strong time dependence of ocean acidification mitigation by atmospheric carbon dioxide removal

In Paris in 2015, the global community agreed to limit global warming to well below 2 ∘C, aiming at even 1.5 ∘C. It is still uncertain whether these targets are sufficient to preserve marine ecosystems and prevent a severe alteration of marine biogeochemical cycles. Here, we show that stringent mitigation strategies consistent with the 1.5 ∘C scenario could, indeed, provoke a critical difference for the ocean’s carbon cycle and calcium carbonate saturation states. Favorable conditions for calcifying organisms like tropical corals and polar pteropods, both of major importance for large ecosystems, can only be maintained if CO2 emissions fall rapidly between 2025 and 2050, potentially requiring an early deployment of CO2 removal techniques in addition to drastic emissions reduction. Furthermore, this outcome can only be achieved if the terrestrial biosphere remains a carbon sink during the entire 21st century

Making or breaking climate targets: The AMPERE study on staged accession scenarios for climate policy

This study explores a situation of staged accession to a global climate policy regime from the current situation of regionally fragmented and moderate climate action. The analysis is based on scenarios in which a front runner coalition -- the EU or the EU and China -- embarks on immediate ambitious climate action while the rest of the world makes a transition to a global climate regime between 2030 and 2050. We assume that the ensuing regime involves strong mitigation efforts but does not require late joiners to compensate for their initially higher emissions. Thus, climate targets are relaxed, and although staged accession can achieve significant reductions of global warming, the resulting climate outcome is unlikely to be consistent with the goal of limiting global warming to 2 degrees. The addition of China to the front runner coalition can reduce pre-2050 excess emissions by 20.30%, increasing the likelihood of staying below 2 degrees. Not accounting for potential co-benefits, the cost of front runner action is found to be lower for the EU than for China. Regions that delay their accession to the climate regime face a trade-off between reduced short term costs and higher transitional requirements due to larger carbon lock-ins and more rapidly increasing carbon prices during the accession period

Negative-index bi-anisotropic photonic metamaterial fabricated by direct laser writing and silver shadow evaporation

We present the blueprint for a novel negative-index metamaterial. This structure is fabricated via three-dimensional two-photon direct laser writing and silver shadow evaporation. The comparison of measured linear optical spectra with theory shows good agreement and reveals a negative real part of the refractive index at around 3.85 micrometer wavelength - despite the fact that the metamaterial structure is bi-anisotropic due to the lack of inversion symmetry along its surface normal.Comment: 8 pages, 3 figure

Strong time dependence of ocean acidification mitigation by atmospheric carbon dioxide removal

In Paris in 2015, the global community agreed to limit global warming to well below 2 ∘C, aiming at even 1.5 ∘C. It is still uncertain whether these targets are sufficient to preserve marine ecosystems and prevent a severe alteration of marine biogeochemical cycles. Here, we show that stringent mitigation strategies consistent with the 1.5 ∘C scenario could, indeed, provoke a critical difference for the ocean’s carbon cycle and calcium carbonate saturation states. Favorable conditions for calcifying organisms like tropical corals and polar pteropods, both of major importance for large ecosystems, can only be maintained if CO2 emissions fall rapidly between 2025 and 2050, potentially requiring an early deployment of CO2 removal techniques in addition to drastic emissions reduction. Furthermore, this outcome can only be achieved if the terrestrial biosphere remains a carbon sink during the entire 21st century

Increased placental resistance and late decelerations associated with severe proteinuric hypertension predicts poor fetal outcome

CITATION: Pattinson, R. C. et al. 1989. Increased placental resistance and late decelerations associated with severe proteinuric hypertension predicts poor fetal outcome. South African Medical Journal, 75:211-214.The original publication is available at http://www.samj.org.zaThe flow velocity wave forms generated by Doppler ultrasound examination of the umbilical artery were correlated with feto-placental blood flow and numerically expressed as a ratio between the systolic (A) and the end-diastolic point (B). The technique is non-invasive and simple to perform. A cohort analytical study was done to see whether useful information could be obtained from the A/B ratio that could help in the management of patients with severe proteinuric hypertension. Fifty patients with severe proteinuric hypertension at less than 34 weeks' gestation were studied and serial Doppler ultrasound examinations of the umbilical artery were performed. No ultrasound results were made available to the clinician. An A/B ratio of 6 or greater was regarded as increased. Twenty-eight of the patients had an increased A/B ratio; in this group these 14 infants were small for gestational age, 14 developed late decelerations and there were 12 perinatal deaths. The remaining 22 patients had an A/B ratio of less than 6 and only 3 produced infants which were small for gestational age; 2 fetuses developed late decelerations and there was 1 perinatal death. A significant difference was found between the two groups in respect of these results. The group with an abnormal A/B ratio also experienced more neonatal morbidity. The A/B ratio of the umbilical artery wave form may assist in planning delivery of patients with severe proteinuric hypertension more accurately.Publisher’s versio