The UV-Vis spectrum of the ClCO radical in the catalytic cycle of Cl-initiated CO oxidation.

In Venus's mesosphere, the observation/model discrepancy of molecular oxygen, O, abundance has been a long-standing puzzle. Chlorine atoms have been proposed as a catalyst to oxidize carbon monoxide through the formation of chloroformyl radicals (ClCO), removing O and ultimately generating CO. However, relevant kinetic studies of this catalytic cycle are scarce and highly uncertain.

Environmental consequences of interacting effects of changes in stratospheric ozone, ultraviolet radiation, and climate: UNEP Environmental Effects Assessment Panel, Update 2024.

This Assessment Update by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) addresses the interacting effects of changes in stratospheric ozone, solar ultraviolet (UV) radiation, and climate on the environment and human health. These include new modelling studies that confirm the benefits of the Montreal Protocol in protecting the stratospheric ozone layer and its role in maintaining a stable climate, both at low and high latitudes. We also provide an update on projected levels of solar UV-radiation during the twenty-first century.

Atmospheric Chemistry of ()- and ()-CFCFCH═CHCFCF (HFO-153-10mczz): Kinetics and Mechanisms of the Reactions with Cl Atoms, OH Radicals, and O.

Smog chamber experiments were conducted to establish the atmospheric chemistry of ()- and ()-CFCFCH═CHCFCF. Kinetics of the reactions of the two compounds with Cl atoms and OH radicals were measured using relative rate techniques, giving (Cl + ()-CFCFCH═CHCFCF) = (5.63 ± 0.

Environmental plastics in the context of UV radiation, climate change, and the Montreal Protocol.

There are close links between solar UV radiation, climate change, and plastic pollution. UV-driven weathering is a key process leading to the degradation of plastics in the environment but also the formation of potentially harmful plastic fragments such as micro- and nanoplastic particles. Estimates of the environmental persistence of plastic pollution, and the formation of fragments, will need to take in account plastic dispersal around the globe, as well as projected UV radiation levels and climate change factors.

Plastics in the environment in the context of UV radiation, climate change and the Montreal Protocol: UNEP Environmental Effects Assessment Panel, Update 2023.

This Assessment Update by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) considers the interactive effects of solar UV radiation, global warming, and other weathering factors on plastics. The Assessment illustrates the significance of solar UV radiation in decreasing the durability of plastic materials, degradation of plastic debris, formation of micro- and nanoplastic particles and accompanying leaching of potential toxic compounds. Micro- and nanoplastics have been found in all ecosystems, the atmosphere, and in humans.

Assessing the potential climate impact of anaesthetic gases.

There is increasing concern within the health-care community about the role care delivery plays in environmental degradation, sparking research into how to reduce pollution from clinical practice. Inhaled anaesthetics is a particular research area of interest for two reasons. First, several gases are potent greenhouse gases, and waste gas is mostly emitted directly to the environment.

Correction: Atmospheric chemistry of ()- and ()-1,2-dichloroethene: kinetics and mechanisms of the reactions with Cl atoms, OH radicals, and O.

Correction for 'Atmospheric chemistry of ()- and ()-1,2-dichloroethene: kinetics and mechanisms of the reactions with Cl atoms, OH radicals, and O' by Mads P. Sulbaek Andersen , , 2022, , 7356-7373, https://doi.org/10.

Atmospheric chemistry of ()- and ()-1,2-dichloroethene: kinetics and mechanisms of the reactions with Cl atoms, OH radicals, and O.

Smog chambers interfaced with FT-IR detection were used to investigate the kinetics and mechanisms of the Cl atom, OH radical, and O initiated oxidation of ()- and ()-1,2-dichloroethene (CHClCHCl) under atmospheric conditions. Relative and absolute rate methods were used to measure (Cl + ()-CHClCHCl) = (8.80 ± 1.

Atmospheric chemistry of CFCN: kinetics and products of reaction with OH radicals, Cl atoms and O.

Long path length FTIR-smog chamber techniques were used to study the title reactions in 700 Torr of N, oxygen or air diluent at 296 ± 2 K. Values of (Cl + CFCN) = (2.43 ± 0.

Photochemistry of 2,2-dichloroethanol: kinetics and mechanism of the reaction with Cl atoms and OH radicals.

Smog chamber/FTIR techniques were used to investigate the kinetics and mechanism of the Cl atom and OH radical initiated oxidation of 2,2-dichloroethanol at (296 ± 1) K. Relative rate methods were used to measure k(Cl + CHClCHOH) = (5.87 ± 0.

Atmospheric Chemistry of Pentafluorophenol: Kinetics and Mechanism of the Reactions of Cl Atoms and OH Radicals.

Fourier transform infrared smog chamber techniques were used to study the kinetics and mechanisms of the reactions of Cl atoms and OH radicals with pentafluorophenol (CFOH) in 700 Torr total pressure of air or N diluent at 296 ± 2 K. Rate constants (OH + CFOH) = (6.88 ± 1.

Atmospheric chemistry of a cyclic hydro-fluoro-carbon: kinetics and mechanisms of gas-phase reactions of 1-trifluoromethyl-1,2,2-trifluorocyclobutane with Cl atoms, OH radicals, and O.

Long path length FTIR-smog chamber techniques were used to study the title reactions in 700 Torr of N2 or air diluent at 296 ± 2 K. Values of k(Cl + 1-trifluoromethyl-1,2,2-trifluorocyclobutane (TFMTFCB)) = (1.16 ± 0.

Atmospheric chemistry of hexa- and penta-fluorobenzene: UV photolysis and kinetics and mechanisms of the reactions of Cl atoms and OH radicals.

Photochemical reactors were used to study the kinetics and mechanisms of reactions of Cl atoms and OH radicals with hexa- and penta-fluorobenzene (C6F6, C6F5H) in 700 Torr total pressure of N2, air, or O2 diluent at 296 ± 2 K. C6F6 and C6F5H undergo ring-opening following 254 nm UV irradiation, but with small quantum yields (φ < 0.03).

Atmospheric chemistry of (Z)-CFCH[double bond, length as m-dash]CHCl: products and mechanisms of the Cl atom, OH radical and O reactions, and role of (E)-(Z) isomerization.

The chemical mechanisms of the OH radical, Cl-atom and O3 initiated oxidation of (Z)-CF3CH[double bond, length as m-dash]CHCl were studied at 296 ± 1 K in 10-700 Torr air of N2/O2 diluent. Cl atoms add to the [double bond splayed left]C[double bond, length as m-dash]C[double bond splayed right] double bond: 12 ± 5% to the terminal carbon and 85 ± 5% to the central carbon. In 700 Torr of air the products are CF3CHClCHO, HCOCl, CF3COCl, CF3CHO, (E)-CF3CH[double bond, length as m-dash]CHCl, CF3C(O)CHCl2, and CF3CHClCOCl.

Atmospheric Chemistry of (CF)CF-C≡N: A Replacement Compound for the Most Potent Industrial Greenhouse Gas, SF.

FTIR/smog chamber experiments and ab initio quantum calculations were performed to investigate the atmospheric chemistry of (CF)CFCN, a proposed replacement compound for the industrially important sulfur hexafluoride, SF. The present study determined k(Cl + (CF)CFCN) = (2.33 ± 0.

Atmospheric chemistry of Z- and E-CFCH[double bond, length as m-dash]CHCF.

The atmospheric fates of Z- and E-CFCH[double bond, length as m-dash]CHCF have been studied, investigating the kinetics and the products of the reactions of the two compounds with Cl atoms, OH radicals, OD radicals, and O. FTIR smog chamber experiments measured: k(Cl + Z-CFCH[double bond, length as m-dash]CHCF) = (2.59 ± 0.

Atmospheric Chemistry of Tetrahydrofuran, 2-Methyltetrahydrofuran, and 2,5-Dimethyltetrahydrofuran: Kinetics of Reactions with Chlorine Atoms, OD Radicals, and Ozone.

FTIR smog chamber techniques were used to study the kinetics of the gas-phase reactions of Cl atoms, OD radicals, and O3 with the five-membered ring-structured compounds tetrahydrofuran (C4H8O, THF), 2-methyltetrahydrofuran (CH3C4H7O, 2-MTHF), 2,5-dimethyltetrahydrofuran ((CH3)2C4H5O, 2,5-DMTHF), and furan (C4H4O). The rate coefficients determined using relative rate methods were kTHF+Cl = (1.96 ± 0.

Atmospheric Chemistry of (CF3)2CHOCH3, (CF3)2CHOCHO, and CF3C(O)OCH3.

Smog chambers with in situ FTIR detection were used to measure rate coefficients in 700 Torr of air and 296 ± 2 K of: k(Cl+(CF3)2CHOCH3) = (5.41 ± 1.63) × 10(-12), k(Cl+(CF3)2CHOCHO) = (9.

Long-term decline of global atmospheric ethane concentrations and implications for methane.

After methane, ethane is the most abundant hydrocarbon in the remote atmosphere. It is a precursor to tropospheric ozone and it influences the atmosphere's oxidative capacity through its reaction with the hydroxyl radical, ethane's primary atmospheric sink. Here we present the longest continuous record of global atmospheric ethane levels.

Medical intelligence article: assessing the impact on global climate from general anesthetic gases.

Although present in the atmosphere with a combined concentration approximately 100,000 times lower than carbon dioxide (i.e., the principal anthropogenic driver of climate change), halogenated organic compounds are responsible for a warming effect of approximately 10% to 15% of the total anthropogenic radiative forcing of climate, as measured relative to the start of the industrial era (approximately 1750).