Abstract The historical view of an equable Jurassic greenhouse world has been challenged by recent studies documenting recurrent alternation between contrasting climate modes. Cooling of high-latitudinal areas may have been caused by orogenic processes at the northern margin of the Tethys Ocean that reduced heat transport towards the polar regions. Warm phases correlate to periods of intensified volcanism. The Jenkyns Event occurred during the transition from a late Pliensbachian icehouse into an early Toarcian greenhouse. Parallel evolution of different environmental processes, including sea level, climate and carbon cycle, indicate a causal mechanism tied to astronomical forcing. Insolation-controlled variations in the extent of the cryosphere (ice caps and permafrost) facilitated orbitally paced sea-level cycles via waxing and waning of the polar ice caps, and negative carbon isotope excursions via the release of cryosphere-bound 12 C-enriched carbon. This review and synthesis of sedimentological, geochemical and palaeontological palaeoenvironment indicators, and of simulations from climate models, aims to reconstruction, in particular, the high-latitudinal environmental conditions of late Pliensbachian–early Toarcian times. Focus is laid on the extent of the regions that were potentially suitable for hosting a cryosphere. An environmental response to cryosphere dynamics is considered to have been a key component of the Jenkyns Event.

Abstract In the last two centuries, demographic expansion and extensive urbanization of volcanic areas have increased the exposure of our society to volcanic hazards. Antarctica is no exception. During the last decades, the permanent settlement and seasonal presence of scientists, technicians, tourists and logistical personnel close to active volcanoes in the south polar region have increased notably. This has led to an escalation in the number of people and the amount of infrastructure exposed to potential eruptions. This requires advancement of our knowledge of the volcanic and magmatic history of Antarctic active volcanoes, significant improvement of the monitoring networks, and development of long-term hazard assessments and vulnerability analyses to carry out the required mitigation actions, and to elaborate on the most appropriate response plans to reduce loss of life and infrastructure during a future volcanic crisis. This chapter provides a brief summary of the active volcanic systems in Antarctica, highlighting their main volcanological features, which monitoring systems are deployed (if any), and recent (i.e. Holocene and/or historical) eruptive activity or unrest episodes. To conclude, some notes about the volcanic hazard assessments carried out so far on south polar volcanoes are also included, along with recommendations for specific actions and ongoing research on active Antarctic volcanism.

Abstract High Mountain Asia contains the largest volume of glacier ice outside the polar regions, and contain the headwaters of some of the largest rivers in central Asia. These glaciers are losing mass at a mean rate of between –0.18 and –0.5 m water equivalent per year. While glaciers in the Himalaya are generally shrinking, those in the Karakoram have experienced a slight mass gain. Both changes have occurred in response to rising air temperatures due to Northern Hemisphere climate change. In the westerly influenced Indus catchment, glacier meltwater makes up a large proportion of the hydrological budget, and loss of glacier mass will ultimately lead to a decrease in water supplies. In the monsoon-influenced Ganges and Brahmaputra catchments, the contribution of glacial meltwater is relatively small compared to the Indus, and the decrease in annual water supplies will be less dramatic. Therefore, enhanced glacier melt will increase river flows until the middle of the twenty-first century, but in the longer term, into the latter part of this century, river flows will decline as glaciers shrink. Declining meltwater supplies may be compensated by increases in precipitation, but this could exacerbate the risk of flooding.

Abstract The Quaternary is the youngest geological period, beginning 2.58 Ma ago and including the present day; it is therefore the only geological period that is continuously growing. During the first epoch of the Quaternary, the Pleistocene, extremely cold and warm conditions alternated, frequently over short periods of time. This resulted in processes currently only operating in cold (polar and high-mountain) environments extending to and affecting the midlatitudes, including the currently densely populated areas of North America and Europe. In Britain every region has been affected by cold-region processes, which have produced unique sedimentary and geomorphological signatures. Hence, an intimate knowledge of these processes is of direct relevance to engineering geologists and anyone working with natural materials. This chapter reviews the state of the art of (a) the stratigraphic (nomenclatorial) framework of the Quaternary, (b) prominent concepts that are of direct relevance to understanding the detailed overviews in Chapters 3 – 5 ; and (c) key findings on the dynamics of these processes and their implications for engineering-geological questions and problems.