The issue of detecting changes beyond the range of natural variability (detection) and of attributing causes to such changes (attribution) are central to any rational debate about anthropogenic climate change. This concept, introduced by Klaus Hasselmann in the late 1970s, is usually not understood by either so-called sceptics or by activist scientists.

Often rigorous detection and attribution analysis is replaced by mere declarations and by naïve applications of methods to determine if certain trends are ‘significant’ or not.

In this talk, the concepts are introduced; the invoked assumptions and the roles of dynamical models and of time-scales are explained. The concept is illustrated with a few examples related to global and regional air temperature and to NE Atlantic storminess.

For global and regional air temperature, the recent variations are found to be beyond the range of natural variability (detection) and the changes are best explained by a dominant contribution by elevated greenhouse gas concentrations. For NE Atlantic storminess recent trends are found to be intermittent and within the historical range of variations. The finding of significant GHG contributions to temperature change and the lack of such for changes in storminess are not contradictions.

This paper summarizes results of magnetostratigraphic and rock magnetic investigations performed on fluvial sediments from the Ludwigshafen-Parkinsel drilling project (Upper Rhine Graben (URG) Germany). The drilling penetrated into Pleistocene gravel, sand, silt and clay, and unconsolidated Pliocene deposits. Its primary objective was the exploration of groundwater resources in the area of Ludwigshafen. Our rock magnetic investigations together with results of heavy mineral analyses (see Hagedorn & Boenigk, 2008) show a clearly structured sediment profile. It was possible to identify the change from mainly locally controlled sedimentation from the Graben margins to a more distinct Alpine controlled sedimentation at a depth of 177 m by magnetic data. Based on lithostratigraphic correlation with other sedimentary records from the URG and also based on palynological evidence, this event happened at the end of Late Pliocene during a time of normal polarity of the Earth's magnetic field (Gauss Chron?). The well-documented characteristic change in magneto-mineralogy from goethite to greigite almost at the same stratigraphic level, we interpret solely as a climatic signal which can be correlated with the global climate change at ∼2.5 Ma that is well documented in a wide range of sedimentary environments (e.g. deep-sea sediments, loess).

Remains of Late Cretaceous birds are rare, which is especially true for Europe and the type area of the Maastrichtian Stage (southeast Netherlands, northeast Belgium) in particular. In the present paper, we record new remains (isolated tarsometatarsus and radius) that document the presence of both enantiornithine and ornithurine birds in the Maastrichtian area. These fossils, although fragmentary, are important in view of their stratigraphic age: all bird remains discovered to date in the Maastricht area are amongst the youngest ’non-modern’ avians known, originating from strata deposited less than 500,000 years prior to the end of the Cretaceous Period.

Recent core drillings, carried out during water-economic exploration in the area of Mannheim/Ludwigshafen/Schifferstadt (Rhine-Neckar region, Germany), have produced a more differentiated stratigraphic division of the Pleistocene sediments of the northern Upper Rhine Graben. Pollen analytical investigations as well as malacological, heavy mineral, palaeomagnetic and lithological research have led to a stratigraphic reinterpretation of the gravel layers and intermediate horizons. Based on the results of the pollen analyses, the Mannheim interglacial period in the upper intermediate horizon (Oberer Zwischenhorizont, OZH) cannot be assigned to the Eemian as stated earlier. The occurrence of Fagus, Celtis and Azolla, along with the results of malacological analyses, indicate a Cromerian age for the Mannheim Interglacial. In addition, a pollen sequence from a different interglacial in the core sediments from Schifferstadt could also be assigned to the Cromerian. The Schifferstadt Interglacial is divided into a lower optimum phase with high values of Ulmus, Quercus and Corylus while Carpinus is completely absent, and an upper optimum phase with low values of Carpinus. Fagus is absent in the whole sequence. The OZH comprises not only the two interglacial pollen sequences described above but also parts of at least four Middle Pleistocene Interglacials. In the lower part of the drillings in Schifferstadt and Ludwigshafen, which are assigned to the Early Pleistocene, pollen assemblages with Fagus are likely to correlate with parts of the Tiglian A substage. There is a clear change to a Tertiary type of pollen flora at 91 m at Schifferstadt and at 186 m in Ludwigshafen.

During the warm Bølling-Allerød interstadial, tree species migrated from their refugia in southern Europe northwards into the area within the present temperate climatic zone. It is evident from high levels of charcoal in fossil records in this region that, especially during the later part of the Bølling-Allerød interstadial, many fires occurred. The start of the Younger Dryas was characterised by rapid and intense cooling and rising water tables, with catastrophic effects on the vegetation. Thermophilous pine trees could not survive the cold Younger Dryas climate. Dead wood provided an abundant source of fuel for intense, large-scale fires seen in many records as a concentration of charcoal particles in so-called ’Usselo-soils’ dated to ca 10,950 14C BP. A similar trend in increased charcoal indicating increased burning is seen at many sites across North America at this time and it has been suggested by Firestone et al. (2007) that this was caused by an explosion of extra-terrestrial material over northern North America, causing the Younger Dryas climate cooling and Megafaunal extinction. We argue that there is no need to invoke an extraterrestrial cause to explain the charcoal in the fossilized soils. The volume of forest trees that died as a result of the cold Younger Dryas climate would easily have supplied sufficient fuel for intense, large-scale fires and can be used to account for the concentration of charcoal particles. As soils were no longer covered by dense vegetation, much erosion occurred during the Younger Dryas and therefore, at many places, Usselo soils, rich in charcoal, were preserved under aeolian sand dunes.

The practice of climate simulation takes place in a polarized social and political context. In this paper some methodological aspects of the practice of climate simulation are addressed and the potential value-ladenness of modelling assumptions is discussed. I claim that there is clearly a plurality of values guiding climate simulation efforts with climate scientists themselves also commonly holding different political views on the climate-change problem. There exist climate models of varying levels of concreteness and with different basic assumptions, and the modelling approaches behind these models are valued differently by different groups of climate scientists. The social and political context in which the climate modelling is done plays a role in these value judgements. In order to prevent one particular group of models from dominating the field for social and/or political reasons, the climate-modelling community should acknowledge the vital and necessary role of plurality in the practice of climate science and should stimulate reflection within this practice. Finally, while the IPCC partly addresses the issue by presenting model ensembles, the uncertainties in climate simulation should be better communicated to policy makers and politicians.

The vegetation of the northern Upper Rhine Graben (southwestern Germany) is reconstructed for the end of the Lateglacial and the Holocene by means of palynological analyses in combination with AMS 14c dating. Analogous to adjacent lowland areas, the Younger Dryas climatic deterioration did not result in a complete deforestation of the area and open pine woodlands with locally birch stands and shrubs persisted. A subdivision of the Younger Dryas period, into a humid first phase, followed by a dry second phase was also reflected in our records. For the Holocene, the pollen diagrams show two regionally different vegetation developments, related to substrate and variations in annual precipitation: in the south the ‘classical’ succession of pine then hazel is followed by other deciduous trees, whereas in the northern part, pine kept its dominance far into the Subboreal.

Is it possible to step twice into the same river? That is the question I would like to put to you. At first glance, there is no reason to assume that a river will not look exactly the same tomorrow as it does today. And we tend to forget whether it was different yesterday or the day before. ‘Will the weather ever get any better?’ we tend to say to each other after a couple of rainy days. Will we ever see a cold winter again with an Elfstedentocht? Fortunately, some people keep records of the weather, or keep track of rivers flooding or falling dry. That makes it possible to know for sure what stays the same and what changes.

The Plio-Pleistocene succession in the Lower Rhine Embayment was subjected to a thorough revision of existing stratigraphic concepts. The deposits were studied at key sites in the type area near Venlo and in the large open-cast mine Hambach in the southern part of the Lower Rhine Embayment by means of sedimentological, petrographical, as well as palaeo- and rockmagnetic methods.

The work has yielded improved insights of the drainage pattern and the Late Pliocene and Early Pleistocene depositional history of the region. As a result, a new comprehensive lithostratigraphical framework has been established.

Study of the succession at Hambach showed the occurrence of deposits of the Rhine, Meuse and a local river in the Lower Pleistocene part of the succession. Paleo- and rockmagnetic studies of the deposits marking the transition from Pliocene to Pleistocene indicate that the Gauss-Matuyama magnetic reversal occurs several meters above the top of the Reuver Clay at Hambach.

The study of the Lower Pleistocene succession in the type area has confirmed the recently new established lithostratigraphic framework of the Netherlands. As a consequence, the previous Dutch lithostratigraphic system which forms the basis of the chronostratigraphic subdivision of the Pliocene and Early Pleistocene of NW Europe has been proven to be inappropriate and should be abandoned. This chronostratigraphic framework is based on the interpretation of palynological data and was first established in the Netherlands during the 1960s. The new lithostratigraphic concept has revealed numerous contradictions with the chronostratigraphic framework. Based on these results it is proposed to abandon the chronostratigraphic subdivision of the Early Pleistocene in northwestern Europe.

The fluvial history of the northern Lower Rhine Embayment shows interplay of three main river systems: Rhine, Meuse and smaller rivers draining the central and northern part of Belgium.

The Pliocene and Early Pleistocene (pre-)Rhine and Meuse river systems had their conjunction in the southern part of the Roer Valley Graben between Aachen and Jülich. Despite slight differences in the heavy-mineral assemblages the lithological composition of the Pliocene deposits of the three river systems shows close resemblance and therefore they cannot be mapped separately. However, due to a marked change of the petrographical composition the Upper Pliocene and Lower Pleistocene deposits of the Rhine are easily recognised and as a result Rhine and Meuse deposits can be mapped separately upstream of their confluence.

The Lower Pleistocene deposits of Rhine, Meuse and the Belgian rivers show a clear interrelationship. They are bounded by two regional well-mapable unconformities and are preserved in from west to east changing lithostratigraphical sequences. Revision of the lithostratigraphical schemes in Germany and the Netherlands and the better defined lithostratigraphical position of Meuse deposits in Germany now strongly constrain the correlation of the various fluvial deposits. As a result existing reconstructions of the fluvial deposition and tectonic history of the southern Roer Valley Graben can be evaluated and re-adjusted.

It is concluded that the main course of the Meuse was aligned through the so-called East Meuse valley during the larger part of the Early Pleistocene. Available pollen data do not conflict with this conclusion. At the same time the Rhine ceased to enter the southern part of the Roer Valley Graben. Instead, the Meuse accumulated here a series of deposits derived from the East-Meuse valley. Simultaneously, the Belgian rivers filled available accommodation space in the Roer Valley Graben of the southern Netherlands. The conclusions are based primarily on the revised lithostratigraphical framework. In general they simplify the picture of fluvial and tectonic behaviour of the area.