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Fant 8714 publikasjoner. Viser side 346 av 349:


Wetland emission and atmospheric sink changes explain methane growth in 2020

Peng, Shushi; Lin, Xin; Thompson, Rona Louise; Xi, Yi; Liu, Gang; Hauglustaine, Didier; Lan, Xin; Poulter, Benjamin; Ramonet, Michel; Saunois, Marielle; Yin, Yi; Zhang, Zhen; Zheng, Bo; Ciais, Philippe

Atmospheric methane growth reached an exceptionally high rate of 15.1 ± 0.4 parts per billion per year in 2020 despite a probable decrease in anthropogenic methane emissions during COVID-19 lockdowns. Here we quantify changes in methane sources and in its atmospheric sink in 2020 compared with 2019. We find that, globally, total anthropogenic emissions decreased by 1.2 ± 0.1 teragrams of methane per year (Tg CH4 yr−1), fire emissions decreased by 6.5 ± 0.1 Tg CH4 yr−1 and wetland emissions increased by 6.0 ± 2.3 Tg CH4 yr−1. Tropospheric OH concentration decreased by 1.6 ± 0.2 per cent relative to 2019, mainly as a result of lower anthropogenic nitrogen oxide (NOx) emissions and associated lower free tropospheric ozone during pandemic lockdowns. From atmospheric inversions, we also infer that global net emissions increased by 6.9 ± 2.1 Tg CH4 yr−1 in 2020 relative to 2019, and global methane removal from reaction with OH decreased by 7.5 ± 0.8 Tg CH4 yr−1. Therefore, we attribute the methane growth rate anomaly in 2020 relative to 2019 to lower OH sink (53 ± 10 per cent) and higher natural emissions (47 ± 16 per cent), mostly from wetlands. In line with previous findings, our results imply that wetland methane emissions are sensitive to a warmer and wetter climate and could act as a positive feedback mechanism in the future. Our study also suggests that nitrogen oxide emission trends need to be taken into account when implementing the global anthropogenic methane emissions reduction pledge.


WG5 session on source apportionment and planning

Guerreiro, Cristina; Pisoni, E.; Belis, C.; Pirovano, G.; Monteiro, A.; Clappier, A.; Thunis, P.


What caused a record high PM10 episode in northern Europe in October 2020?

Zwaaftink, Christine Groot; Aas, Wenche; Eckhardt, Sabine; Evangeliou, Nikolaos; Hamer, Paul David; Johnsrud, Mona; Kylling, Arve; Platt, Stephen Matthew; Stebel, Kerstin; Uggerud, Hilde Thelle; Yttri, Karl Espen

In early October 2020, northern Europe experienced an episode with poor air quality due to high concentrations of particulate matter (PM). At several sites in Norway, recorded weekly values exceeded historical maximum PM10 concentrations from the past 4 to 10 years. Daily mean PM10 values at Norwegian sites were up to 97 µg m−3 and had a median value of 59 µg m−3. We analysed this severe pollution episode caused by long-range atmospheric transport based on surface and remote sensing observations and transport model simulations to understand its causes. Samples from three sites in mainland Norway and the Arctic remote station Zeppelin (Svalbard) showed strong contributions from mineral dust to PM10 (23 %–36 % as a minimum and 31 %–45 % as a maximum) and biomass burning (8 %–16 % to 19 %–21 %). Atmospheric transport simulations indicate that Central Asia was the main source region for mineral dust observed in this episode. The biomass burning fraction can be attributed to forest fires in Ukraine and southern Russia, but we cannot exclude other sources contributing, like fires elsewhere, because the model underestimates observed concentrations. The combined use of remote sensing, surface measurements, and transport modelling proved effective in describing the episode and distinguishing its causes.


What do we know about the production and release of persistent organic pollutants in the global environment?

Li, Li; Cheng, Chengkang; Li, Dingsheng; Breivik, Knut; Abbasi, Golnoush; Li, Yi-Fan

Information on the global production and environmental releases of persistent organic pollutants (POPs) is of critical importance for regulating and eliminating these chemical substances of worldwide environmental and health concerns. Here, we conduct an extensive literature review to collect and curate quantitative information on the historical global production and multimedia environmental releases of 25 intentionally produced POPs. Our assembled data indicate that as of 2020, a cumulative total of 31 306 kilotonnes (kt) of the 25 POPs had been synthesized and commercialized worldwide, resulting in cumulative releases of 20 348 kt into the global environment. As of 2020, short-chain chlorinated paraffins were the most produced POP, with a historical global cumulative tonnage amounting to 8795 kt, whereas α-hexachlorocyclohexane (HCH) had the largest historical global cumulative environmental releases of 6567 kt among these 25 POPs. The 1970s witnessed the peak in the annual global production of the 25 investigated POPs. The United States and Europe used to be the hotspots of environmental releases of the 25 investigated POPs, notably in the 1960s and 1970s. By contrast, global environmental releases occurred primarily in China in the 2000s–2010s. Preliminary efforts are also made to integrate the production volume information with “hazard” attributes (persistence, bioaccumulation, toxicity, and long-range transport potential) in the evaluation of potential environmental impacts of the 25 POPs. The results show that dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCBs) are potentially associated with higher environmental impacts than other POPs because they are among the top rankings in both the global cumulative production and hazard indicators. This work for the first time reveals the astonishing magnitudes of POP production and environmental releases in contemporary human history. It also underscores the importance of tonnage information in assessments of POPs, POP candidates, and other chemicals of emerging concern.


What is the effect of phasing out long-chain per- and polyfluoroalkyl substances on the concentrations of perfluoroalkyl acids and their precursors in the environment? A systematic review

Land, Magnus; de Wit, Cynthia A.; Bignert, Anders; Cousins, Ian T.; Herzke, Dorte; Johansson, Jana H.; Martin, Jonathan W.

There is a concern that continued emissions of man-made per- and polyfluoroalkyl substances (PFASs) may cause environmental and human health effects. Now widespread in human populations and in the environment, several PFASs are also present in remote regions of the world, but the environmental transport and fate of PFASs are not well understood. Phasing out the manufacture of some types of PFASs started in 2000 and further regulatory and voluntary actions have followed. The objective of this review is to understand the effects of these actions on global scale PFAS concentrations.


What is the impact of mercury contamination on human health in the Arctic?

Stow, J.; Krümmel, E.; Leech, T.; Donaldson, S.; Hansen, J.C.; Van Oostdam, J.; Gilman, A.; Odland, J.Ø.; Vaktskjold, A.; Dudarev, A.; Ayotte, P.; Berner, J.E.; Bonefeld-Jørgensen, E.C.; Carlsen, A.; Dewailly, E.; Donaldson, S.G.; Furgal, C.; Gilman, A.; Muckle, G.; Ólafsdóttir, K.; Pedersen, H.S.; Rautio, A.; Sandanger, T.M.; Savolainen, M.; Skinner, K.; Tikhonov, C.; Weber, J.-P.; Weihe, P.


What is the status of the Mediterranean Sea and its atmosphere? What has been learned from over-water intensive mercury measurements along 6000 km cruise path.

Pirrone, N.; Ammiraglia, L.; Breg, T.; Ceccarini, C.; Cipriani, F.; Costa, P.; Fajon, V.; Ferrara, Gardfeldt, K.; Gensini, M.; Horvat, M.; Kotnik, J.; Logar, M.; Mamane, Y.; Melamed, E.; Yossef, O.; Pesenti, E.; Sommar, J.; Sekkesæter, S.; Sprovieri, F.; Valdal, A.K.


What makes a good OSSE? NILU F

Lahoz, W.A.


What we have learned in validating Aerosol_cci pixel level uncertainties?

Stebel, K.; Povey, A.; Popp, T.; Capelle, V.; Clarisse, L.; Heckel, A.; Kinne, S.; Klueser, L.; Kolmonen, P.; Kosmale, M.; de Leeuw, G.; North, P. R. J.; Pinnock, S.; Sogacheva, L.; Thomas, G.; Vandenbussche, S.


Where are we in the definition of the optimal satellite instrument to measure ozone for air quality?

Attie, J.-L.; El Amraoui, L.; Lahoz, W.; Quesada, S.; Ricaud, P.; Zbinden, R.


Where does mercury in the Arctic environment come from, and how does it get there?

Munthe, J.; Goodsite, M.; Berg, T.; Chételat, J.; Dastoor, A.; Douglas, T.; Durnford, D.; Goodsite, M.; Macdonald, R.; Muir, D.; Outridge, P.; Pacyna, J.; Ryzhkov, A.; Skov, H.; Steffen, A.; Sundseth, K.; Travnikov, O.; Wängberg, I.; Wilson, S.


Where does the optically detectable aerosol in the European Arctic come from?

Stock, M.; Ritter, C.; Aaltonen, V.; Aas, W.; Handorff, D.; Herber, A.; Treffeisen, R.; Dethloff, K.


White-Tailed Eagle (Haliaeetus albicilla) Body Feathers Document Spatiotemporal Trends of Perfluoroalkyl Substances in the Northern Environment

Sun, Jiachen; Bossi, Rossana; Bustnes, Jan Ove; Helander, Björn; Boertmann, David; Dietz, Rune; Herzke, Dorte; Jaspers, Veerle; Labansen, Aili Lage; Lepoint, Gilles; Schulz, Ralf; Sonne, Christian; Thorup, Kasper; Tøttrup, Anders; Zubrod, Jochen P.; Eens, Marcel; Eulaers, Igor


White-tailed eagle (Haliaeetus albicilla) feathers from Norway are suitable for monitoring of legacy, but not emerging contaminants

Løseth, Mari Engvig; Briels, Nathalie; Flo, Jørgen; Malarvannan, Govindan; Poma, Giulia; Covaci, Adrian; Herzke, Dorte; Nygård, Torgeir; Bustnes, Jan Ove; Jenssen, Bjørn Munro; Jaspers, Veerle

While feathers have been successfully validated for monitoring of internal concentrations of heavy metals and legacy persistent organic pollutants (POPs), less is known about their suitability for monitoring ofemerging con- taminants (ECs). Our study presents a broad investigation ofboth legacy POPs and ECs in non-destructivematri- ces from a bird of prey. Plasma and feathers were sampled in 2015 and 2016 from 70 whitetailed eagle (Haliaeetus albicilla) nestlings from two archipelagos in Norway. Preen oil was also sampled in 2016. Samples were analysed for POPs (polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorinated pesticides (OCPs)) and ECs (per- and polyfluoroalkyl substances (PFASs), dechlorane plus (DPs), phosphate and novel brominated flame retardants (PFRs and NBFRs)). A total of nine PCBs, three OCPs, one PBDE and one PFAS were detected in over 50% of the plasma and feather samples within each sampling year and location. Significant and positive correlationswere found between plasma, feathers and preen oil concentrations of legacy POPs and confirm the findings ofprevious research on the usefulness of these matrices for non-destructive mon- itoring. In contrast, the suitability of feathers for ECs seems to be limited. Detection frequencies (DF) of PFASs were higher in plasma (mean DF: 78%) than in feathers (mean DF: 38%). Only perfluoroundecanoic acid could be quantified in over 50% ofboth plasma and feather samples, yet their correlation was poor and not significant. The detection frequencies of PFRs, NBFRs and DPs were very low in plasma (mean DF: 1–13%), compared to feathers (meanDF: 10–57%). Thismay suggest external atmospheric deposition, rapid internal biotransformation or excretion of these compounds. Accordingly, we suggest prioritising plasma for PFASs analyses, while the sources of PFRs, NBFRs and DPs in feathers and plasma need further investigation.