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High-resolution records of calibrated proxy data for the past millennium are fundamental to place current changes into the context of pre-industrial natural forced and unforced variability. Although the need for regional spatially-explicit comprehensive reconstructions is widely recognized, the proxy data sources are still scarce, particularly for the Southern Hemisphere and especially for South America. We present a 600-year long warm season temperature record from varved sediments of Lago Plomo, a proglacial lake of the Northern Patagonian Ice field in Southern Chile (46°59′S, 72°52′W, 203 m a.s.l.). The thickness of the bright summer sediment layer relative to the dark winter layer (measured as total brightness; % reflectance 400–730 nm) is calibrated against warm season SONDJF temperature (1900–2009; r = 0.58, p (aut) = 0.056, RE = 0.52; CE = 0.15, RMSEP = 0.28 °C; five-year triangular filtered data). In Lago Plomo, warm summer temperatures lead to enhanced glacier melt and suspended sediment transport, which results in thicker light summer layers and to brighter sediments. Although Patagonia shows pronounced regional differences in decadal temperature trends and variability, the 600 years temperature reconstruction from Lago Plomo compares favourably with other regional/continental temperature records, but also emphasizes significant regional differences for which no data and information existed so far. These regional differences seem to be real as they are also reflected in modern climate data sets (1900–2010). The reconstruction shows pronounced subdecadal – multidecadal variability with cold phases during parts of the Little Ice Age (16th and 18th centuries) and in the beginning of the 20th century. The most prominent warm phase is the 19th century which is as warm as the second half of the 20th century. The exceptional summer warmth AD 1780–1810 is also found in other archives of Northern Patagonia and Central Chile. Our record shows the delayed 20th century warming in the Southern Hemisphere. The comparison between winter precipitation and summer temperature (inter-seasonal coupling) from Lago Plomo reveals alternating phases with parallel and contrasting decadal trends of winter precipitation and summer temperature (positive and negative running correlations R winter PP; summer TT ). This observation from the sediment proxy data is also confirmed by two sets of reanalysis data for the 20th century. Reanalysis data show that phases with negative correlations between winter precipitation and summer temperature (e.g., dry winters and warm summers) at Lago Plomo are characteristic for periods when circumpolar Westerly flow is displaced southward and enhanced around 60°S.

Climate and environmental reconstructions from natural archives are important for the interpretation of current climatic change. Few quantitative high-resolution reconstructions exist for South America which is the only land mass extending from the tropics to the southern high latitudes at 56°S. We analyzed sediment cores from two adjacent lakes in Northern Chilean Patagonia, Lago Castor (45°36′S, 71°47′W) and Laguna Escondida (45°31′S, 71°49′W). Radiometric dating (210Pb, 137Cs, 14C-AMS) suggests that the cores reach back to c. 900 BC (Laguna Escondida) and c. 1900 BC (Lago Castor). Both lakes show similarities and reproducibility in sedimentation rate changes and tephra layer deposition. We found eight macroscopic tephras (0.2–5.5 cm thick) dated at 1950 BC, 1700 BC, at 300 BC, 50 BC, 90 AD, 160 AD, 400 AD and at 900 AD. These can be used as regional time-synchronous stratigraphic markers. The two thickest tephras represent known well-dated explosive eruptions of Hudson volcano around 1950 and 300 BC. Biogenic silica flux revealed in both lakes a climate signal and correlation with annual temperature reanalysis data (calibration 1900–2006 AD; Lago Castor r = 0.37; Laguna Escondida r = 0.42, seven years filtered data). We used a linear inverse regression plus scaling model for calibration and leave-one-out cross-validation (RMSEv = 0.56 °C) to reconstruct sub decadal-scale temperature variability for Laguna Escondida back to AD 400. The lower part of the core from Laguna Escondida prior to AD 400 and the core of Lago Castor are strongly influenced by primary and secondary tephras and, therefore, not used for the temperature reconstruction. The temperature reconstruction from Laguna Escondida shows cold conditions in the 5th century (relative to the 20th century mean), warmer temperatures from AD 600 to AD 1150 and colder temperatures from AD 1200 to AD 1450. From AD 1450 to AD 1700 our reconstruction shows a period with stronger variability and on average higher values than the 20th century mean. Until AD 1900 the temperature values decrease but stay slightly above the 20th century mean. Most of the centennial-scale features are reproduced in the few other natural climate archives in the region. The early onset of cool conditions from c. AD 1200 onward seems to be confirmed for this region.

High-resolution records of calibrated proxy data for the past 2000 yr are fundamental to place current changes into the context of pre-industrial natural forced and unforced variability. Although the need for regional spatially explicit comprehensive reconstructions is widely recognized, the proxy data sources are still scarce, particularly for the Southern Hemisphere and South America. We provide a 1500 yr long warm season temperature record from varved Lago Plomo, a proglacial lake of the Northern Patagonian Ice field in southern Chile (46°59' S, 72°52' W, 203 m). The thickness of the bright summer sediment layer relative to the dark winter layer (measured as total brightness; % reflectance 400–730 nm) is calibrated against warm season SONDJF temperature (1900–2009; r = 0.58, p(aut) = 0.056, RE = 0.52; CE = 0.15, RMSEP = 0.28 °C; five-year triangular filtered data). In Lago Plomo, warm summer temperatures lead to enhanced glacier melt and suspended sediment transport, which results in a thicker light summer layer and to brighter sediments (% total brightness). Although Patagonia shows pronounced regional differences in decadal temperature trends and variability, the 1500 yr temperature reconstruction from Lago Plomo compares favourably with other regional/continental temperature records but also emphasizes significant regional differences for which no data and information existed so far. The reconstruction shows pronounced sub-decadal–multi-decadal variability with cold phases in the 5th, 7th and 9th centuries, during parts of the Little Ice Age chronozone (16th and 18th centuries) and in the beginning of the 20th century. The most prominent warm phase is the 19th century which is as warm as the second half of the 20th century, emphasizing a delayed recent global warming in the Southern Hemisphere. The comparison between winter precipitation and summer temperature (inter-seasonal coupling) from Lago Plomo reveals alternating phases with parallel and contrasting decadal trends of winter precipitation and summer temperature and positive and negative running correlations(winterPP;summerTT). In the 20th century the trend of this correlation changes at 1920, 1945 and 1975 AD, and the phases with positive (negative) correlations inferred from the lake sediments are also found as a regional robust pattern in reanalysis data, and coincide with the changes of the instrumental PDO index. Enhanced circumpolar flow around 60° S is proposed for positive phases of PDO which leads to the reversed coupling and contrasting decadal trends of winter precipitation and summer temperature during PDO positive phases. Our reconstruction of the inter-seasonal coupling back to 1530 AD reproduces many features of existing PDO reconstructions from the Pacific suggesting that Lago Plomo provides a record for the regional expression of the PDO in Patagonia.

Jahrlich fallen weltweit mehrere hundert Millionen Tonnen behandlungsbedurftiger, u.a. chemischer, Abfalle an, die zu uber 90% aus den 25 OECD-Staaten stammen. Aufgrund ihrer z.T. erheblichen Toxizitat sind besondere, kostentrachtige Masnahmen zu ihrer Beseitigung oder sicheren Deponierung erforderlich. Nach Angaben des Sekretariats des ‘Basler Ubereinkommens uber die Kontrolle der grenzuberschreitenden Verbringung gefahrlicher Abfalle und ihrer Entsorgung vom 22. Marz 1989’ werden inzwischen jahrlich mindestens 8,5 Millionen Tonnen dieser Abfalle grenzuberschreitend gehandelt. Obwohl in diesem Ubereinkommen der Umgang mit solchen Abfallen geregelt ist, findet — im Wesentlichen aus Kostengrunden — in einem nicht unerheblichen Umfang eine illegale internationale Abfallverbringung, verbunden mit einer umweltgefahrdenden Abfallentsorgung, statt. Einem 2006 veroffentlichten Befund des European Network for the Implementation and Enforcement of Environmental Law (IMPEL) zufolge hat der illegale Handel mit giftigem Abfall stetig zugenommen. 3000 Verschiffungsdokumente von 17 europaischen Seehafen wurden untersucht und 258 Schiffsladeraume wurden inspiziert mit dem Ergebnis, dass von 140 Abfallverschiffungen 68 illegal erfolgten. Die Unterbindung des illegalen Transports gefahrlicher Abfalle stost auf verschiedene Hindernisse. Kontrollmasnahmen erfordern betrachtliche personelle, technische und logistische Ressourcen, die nicht in jedem betroffenen Land in ausreichendem Umfang zur Verfugung stehen. Fehlende oder ineffiziente Verwaltungsstrukturen verhindern schnelles Unterbinden illegaler Mullverbringung. Teilweise fehlt auch der politische Wille zur Durchfuhrung der notwendigen Masnahmen. Ein weiteres Problem bereitet der Umstand, dass Abfalle, die beim regularen Schiffsbetrieb anfallen, nicht Gegenstand des Basler Ubereinkommens, sondern des ‘Internationalen Ubereinkommens zur Verhutung der Meeresverschmutzung durch Schiffe’ sind. Die Ausfuhrungsbestimmungen sind im Dokument MARPOL 73/78 zusammengefasst; die Zustandigkeit liegt bei der Internationalen Schifffahrtsorganisation (IMO). Die Herkunftsidentifikation der Abfalle und damit die Festlegung der Zustandigkeit bereiten verschiedentlich Schwierigkeiten, so auch in diesem Fall. Vor diesem Hintergrund wird versucht, die Vorgange um die Ablagerung von Chemieabfallen in Abidjan zu rekonstruieren. Die Rekonstruktion der Ereignisse beruht u.a. auf der Auswertung von Presseartikeln, Verlautbarungen internationaler Regierungsorganisationen, insbesondere der UNO und einzelner ihrer Unterorganisationen, Kommuniques des Sekretariats des Basler Ubereinkommens sowie Stellungnahmen verschiedener NGO’s. Da die Ereignisse vor Ort nur unvollstandig dokumentiert sind, eine offizielle Erklarung der politisch Verantwortlichen fehlt und relevante Firmenunterlagen der Offentlichkeit nicht zuganglich sind, lassen sich Lucken in der Darstellung des Geschehens nicht vermeiden. Die Ereignisse vom August 2006 veranschaulichen, dass die Kontrolle der internationalen Abfallstrome umgangen werden kann. Es bleibt ungeklart, wer die politische Verantwortung fur den Tod von 10 Menschen und fur die aufgetretenen Gesundheitsschaden zu tragen hat. Mogliche straf- und haftungsrechtliche Konsequenzen fur die am Mulldumping beteiligten Akteure und Firmeneigner sind nicht absehbar. Fur die betroffene Bevolkerung von Abidjan stellt sich zudem die Frage nach potentiellen chronischen Gesundheitsschaden und der langfristigen Wirkung ggf. verbliebener Abfallmengen. Die Ereignisse belegen, dass die internationale Kontrolle des Transports und der Behandlung gefahrlicher Abfalle verstarkt werden muss und noch bestehende rechtliche Grauzonen zu beseitigen sind. Die OECD-Staaten sowie alle anderen okonomisch und technisch leistungsfahigen Staaten und Organisationen sollten sich der Herausforderung stellen, die sich entwickelnden Staaten in deren Bemuhen zu unterstutzen, die personellen, technischen und infrastrukturellen Voraussetzungen fur eine effiziente Kontrolle von Abfallimporten zu schaffen.