Insects are highly successful animals inhabiting marine, freshwater and terrestrial habitats from the equator to the poles. As a group, insects have limited ability to regulate their body temperature and have thus required a range of strategies to support life in thermally stressful environments, including behavioural avoidance through migration and seasonal changes in cold tolerance. With respect to overwintering strategies, insects have traditionally been divided into two main groups: freeze tolerant and freeze avoiding, although this simple classification is underpinned by a complex of interacting processes, i.e. synthesis of ice nucleating agents, cryoprotectants, antifreeze proteins and changes in membrane lipid composition. Also, in temperate and colder climates, the overwintering ability of many species is closely linked to the diapause state, which often increases cold tolerance ahead of temperature-induced seasonal acclimatisation. Importantly, even though most species can invoke one or both of these responses, the majority of insects die from the effects of cold rather than freezing. Most studies on the effects of a changing climate on insects have focused on processes that occur predominantly in summer (development, reproduction) and on changes in distributions rather than winter survival per se. For species that routinely experience cold stress, a general hypothesis would be that predicted temperature increases of 1 degree C to 5 degrees C over the next 50-100 years would increase winter survival in some climatic zones. However, this is unlikely to be a universal effect. Negative impacts may occur if climate warming leads to a reduction or loss of winter snow cover in polar and sub-polar areas, resulting in exposure to more severe air temperatures, increasing frequency of freeze-thaw cycles and risks of ice encasement. Likewise, whilst the dominant diapause-inducing cue (photoperiod) will be unaffected by global climate change, higher temperatures may modify normal rates of development, leading to a decoupling of synchrony between diapause-sensitive life-cycle stages and critical photoperiods for diapause induction. In terms of climate warming and potential heat stress, the most recent predictions of summer temperatures in Europe of 40 degrees C or higher in 50-75 years, are close to the current upper lethal limit of some insects. Long-term data sets on insect distributions and the timing of annual migrations provide strong evidence for 'positive' responses to higher winter temperatures over timescales of the past 20-50 years in North America, Europe and Asia.
The worldwide burden of disease is large, with significant negative impacts on the quality of life, including economic productivity. It will be a continuing task to overcome these obstacles. Climate change is an additional challenge that could work for or against efforts to control climate-sensitive diseases. The global community of public health scholars and practitioners is being challenged to take into account the added threats from climate change. The first chapters of this book introduce the basic concepts. The subsequent chapters focus on case studies in public health that may have relevance to adaptation to climate change. The final chapters turn to the policy implications for adaptation to climate change.
The Alaska Climate Research Center is a research and service organization at the Geophysical Institute, University of Alaska Fairbanks, focusing on Alaska and polar regions climatology. The website posts archived climatological data for Alaska.
The Center for Climate Change Law (CCCL) at Columbia Law School develops legal techniques to fight climate change, trains law students and lawyers in their use, and develops databases on climate law and regulation.
While there is no doubt about the role of genetic factors in the aetiology of vascular diseases, especially in the genesis of disorders of the venous system, a place should be reserved for climatic and social factors. By means of an investigation which we undertook in a tropical environment in senegal, we examined the morbidity due to atheromatous disease. This study extended over a period of 30 years, from 1945 to 1975. We found that arteriopathy of the lower limbs due to overload did not exist before 1960. Since 1966, a few cases of myocardial infarction have been noted, and since 1970, a few cases of arteriopathy. These cases are confined to an urban environment which, during the same period, has undergone profound social upheavals. It all seems to be as if there were competition between climatic factors protecting and social factors aggravating. In contrast to the rarity of vascular disorders in hot countries is their high incidence in cold countries. In Canada and Sweden a particular clinical aspect of the disorder has been found: arteriopaths in a subarctic environment suffer more than sensory disturbances than ischaemia. In conclusion, it seems that the environment, in the broad sense of the term, plays a role in the aetiology of atheromatous disease, which has been classified, not without reason, among the diseases of civilization.
The forest-steppe ecotone in southern Siberia is highly sensitive to climate change; global warming is expected to push the ecotone northwards, at the same time resulting in degradation of the underlying permafrost. To gain a deeper understanding of long-term forest-steppe carbon dynamics, we use a highly resolved, multiproxy, palaeolimnological approach, based on sediment records from Lake Baikal. We reconstruct proxies that are relevant to understanding carbon dynamics including carbon mass accumulation rates (CMAR; g C m(-2) yr(-1) ) and isotope composition of organic matter (d(13) CTOC ). Forest-steppe dynamics were reconstructed using pollen, and diatom records provided measures of primary production from near- and off-shore communities. We used a generalized additive model (GAM) to identify significant change points in temporal series, and by applying generalized linear least-squares regression modelling to components of the multiproxy data, we address (1) What factors influence carbon dynamics during early Holocene warming and late Holocene cooling? (2) How did carbon dynamics respond to abrupt sub-Milankovitch scale events? and (3) What is the Holocene carbon storage budget for Lake Baikal. CMAR values range between 2.8 and 12.5 g C m(-2) yr(-1) . Peak burial rates (and greatest variability) occurred during the early Holocene, associated with melting permafrost and retreating glaciers, while lowest burial rates occurred during the neoglacial. Significant shifts in carbon dynamics at 10.3, 4.1 and 2.8 kyr bp provide compelling evidence for the sensitivity of the region to sub-Milankovitch drivers of climate change. We estimate that 1.03 Pg C was buried in Lake Baikal sediments during the Holocene, almost one-quarter of which was buried during the early Holocene alone. Combined, our results highlight the importance of understanding the close linkages between carbon cycling and hydrological processes, not just temperatures, in southern Siberian environments.