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This paper examines a paradoxical issue in tourism's adaptation to climate change and emissions reduction demands. Operators increasingly take tourists to destinations threatened by climate change, with Antarctica and other polar regions as favourites and cruise ship and aircraft as main transport modes. The selling point is to see a destination before it disappears, a form of last chance tourism. This has been claimed to increase the environmental awareness of tourists and make them “ambassadors” for conservation and the visited destination. Antarctic cruise ship passengers tripled from 2000 to 2007. The paper finds that high levels of greenhouse gas emissions are created by cruise ship tourists in general, and especially high levels for those visiting the Antarctic, up to approximately eight times higher per capita and per day than average international tourism trips. A survey found no evidence for the hypothesis that the trips develop greater environmental awareness, change attitudes or encourage more sustainable future travel choices. Of the Antarctic cruise passengers surveyed, 59% felt that their travel did not impact on climate change; fewer than 7% had or might offset their emissions. Alternative opportunities for visitation to glacial/polar destinations that comply with the desire to reduce future emissions are discussed. [ABSTRACT FROM AUTHOR]

A collapse of the West-Antarctic Ice Sheet (WAIS) would cause a sea level rise of 5–6 m, perhaps even within 100 years, with catastrophic consequences. The probability of such a collapse is small but increasing with the rise of the atmospheric concentrations of greenhouse gas and the resulting climate change. This paper investigates how the potential collapse of the WAIS affects the optimal rate of greenhouse gas emission control. We design a decision and learning tree in which decision are made about emission reduction at regular intervals: the decision makers (who act as social planners) have to decide whether to implement the environmental or not (keeping then the flexibility to act later). By investing in the environmental policy, they determine optimally the date of the optimal emission reduction. At the same time, they receive new information on the probability of a WAIS collapse and the severity of its impacts. The probability of a WAIS collapse is endogenous and contingent on greenhouse gas concentrations. We solve this optimisation problem by backward induction. We find that a potential WAIS collapse substantially bring the date of the optimal emission reduction forward and increases its amount if the probability is high enough (a probability of 1% per year for the worst case), if the impacts are high enough (a worst case damage of 10% of GDP for a 3˚C warming) or if the decision maker is risk averse enough (for example a social damage due to pollution equal to 1% GDP for an atmospheric temperature of 3˚C). We also find that, as soon as a WAIS collapse is a foregone fact, emission reduction falls to free up resource to prepare for adapting to the inevitable. By contrast, adaptation (such as building dikes along the coast) postpones policy intervention because that strategy reduces the risk of catastrophic damages. [ABSTRACT FROM AUTHOR]

The climate observations at Orcadas represent the only southern high-latitude site where data span more than a century, and its daily measurements are presented for the first time in this paper. Although limited to a single station, the observed warming trends are among the largest found anywhere on the earth, facilitating the study of changes in extreme temperatures as well as averages. Factors that may influence Antarctic climate include natural variability; changes in greenhouse gases; and, since about the mid-1970s, the development of the ozone hole. The seasonality of observed warming and its temporal evolution during the century are both key for interpretations of Antarctic climate change. No statistically significant climate trends are observed at Orcadas from 1903 to 1950. However, statistically significant warming is evident at Orcadas throughout all four seasons of the year since 1950. Particularly in austral fall and winter, the warming of the cold extremes (coldest 5% and 10% of days) substantially exceeds the warming of the mean or of the warmest days, providing a key indicator for cold season Antarctic climate change studies. Trends in the summer season means and extremes since 1970 are approximately twice as large as those observed earlier, supporting suggestions of additional regional warming in that season because of the effects of ozone depletion on the circulation. Further, in the spring and summer seasons, significant mean warming also occurred prior to the development of the Antarctic ozone hole (i.e., 1950–70), supporting an important role for processes other than ozone depletion, such as greenhouse gas increases, for the climate changes. [ABSTRACT FROM AUTHOR]

In this paper we explore the relationships between the modelled climate of the Last Glacial Maximum (LGM) and that for doubled atmospheric carbon dioxide compared to the pre-industrial climate by analysing the output from an ensemble of runs from the MIROC3.2 GCM. Our results lend support to the idea in other recent work that the Antarctic is a useful place to look for historical data which can be used to validate models used for climate forecasting of future greenhouse gas induced climate changes, at local, regional and global scales. Good results may also be obtainable using tropical temperatures, particularly those over the ocean. While the greater area in the tropics makes them an attractive area for seeking data, polar amplification of temperature changes may mean that the Antarctic provides a clearer signal relative to the uncertainties in data and model results. Our result for Greenland is not so strong, possibly due to difficulties in accurately modelling the sea ice extent. The MIROC3.2 model shows an asymmetry in climate sensitivity calculated by decreasing rather than increasing the greenhouse gases, with 80% of the ensemble having a weaker cooling than warming. This asymmetry, if confirmed by other studies would mean that direct estimates of climate sensitivity from the LGM are likely to be underestimated by the order of half a degree. Our suspicion is, however, that this result may be highly model dependent. Analysis of the parameters varied in the model suggest the asymmetrical response may be linked to the ice in the clouds, which is therefore indicated as an important area for future research. [ABSTRACT FROM AUTHOR]

The world's icy and snowy regions—the cryosphere—are where the most profound changes will occur as the globe continues warming. In many areas, the levels of cryospheric change today are surpassing any seen in the past hundreds to thousands of years. This amplified response has a simple explanation: Most of the cryosphere is, on average, near the freezing point. Small shifts in temperature push large regions to a different physical state. However, while the processes leading to the loss of ice are quickly started, they do not quickly stop. We are on the verge of committing ourselves to sizable increases in sea level. The 2007 Intergovernmental Panel on Climate Change (IPCC) report estimated sea level rise in this century at just 20 to 60 centimeters, but that total did not include contributions from the break-up and flow of ice sheets. The melting of mountain glaciers and ice in Greenland and Antarctica could add an additional meter of sea level rise. An equally important effect may be the feedback that changes in ice—especially the ice-covered ocean—have on climate in both the polar and the temperate regions of the world. The author describes the processes that are rapidly eroding polar ice. [ABSTRACT FROM AUTHOR]

The article offers information on the research conducted by palaeoclimatologists on the implication of concentrations of stable isotopes and trace elements to climatic changes in Antarctica. Researchers believed that such factors infer changes in climate long before they themselves were on the scene. Members of the European Project for Ice Coring in Antarctica (EPICA) collaborated and gathered valuable information including atmospheric gases trapped and preserved in ice cores extracted from the Earth's polar regions. Such information provides scientists with an overview of the cycling of greenhouse gases such as carbon dioxide and methane. Discussed are the details of the experiment undertaken by palaeoclimatologists.

Background Climate change is a natural phenomenon that has been intensified due to increased emissions of greenhouse gases (GHG). It has become an indispensable issue in international negotiations related to global sustainability and is deeply related to the overall status of environmental health in our planet. Methods We compiled an inventory of GHG emissions that resulted from human activities at the Brazilian Antarctic Scientific Station 'Comandante Ferraz' (EACF) and collected emissions data relating to these activities from January to March 2011. The present work aims to identify the sources of GHG emissions, their characteristics, and composition, using as methodology and framework basis the international ISO 14,064:07 and the GHG Protocol. Results We addressed emissions of CO2, CH4, and N2O arising from the use of vehicles, diesel-electric generators, boilers, and wastewater treatment for the sewage treatment plant. We identified that the main GHG emissions derived from the activities of power generation using diesel and boilers (more than 80% of the emissions), adding more than 772 t of CO2 equivalents. Conclusions We identified that the diesel generators and boilers are the most important sources of emission by Expedition XXIX (2010-2011). In that CO2 is principally emitted in relation to electrical energy generation from diesel generators, we emphasize the need for fuel burning reduction through energy consumption reduction. Am. J. Ind. Med. 55:1166-1171, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Antarctica is the most isolated continent on Earth, but it has not escaped the negative impacts of human activity. The unique marine ecosystems of Antarctica and their endemic faunas are affected on local and regional scales by overharvesting, pollution, and the introduction of alien species. Global climate change is also having deleterious impacts: rising sea temperatures and ocean acidification already threaten benthic and pelagic food webs. The Antarctic Treaty System can address local- to regional-scale impacts, but it does not have purview over the global problems that impinge on Antarctica, such as emissions of greenhouse gases. Failure to address human impacts simultaneously at all scales will lead to the degradation of Antarctic marine ecosystems and the homogenization of their composition, structure, and processes with marine ecosystems elsewhere. [ABSTRACT FROM AUTHOR]

Feedbacks on climate change so far identified are predominantly positive, enhancing the rate of change. Loss of sea-ice, increase in desert areas, water vapour increase, loss of tropical rain forest and the restriction of significant areas of marine productivity to higher latitude (thus smaller geographical zones) all lead to an enhancement of the rate of change. The other major feedback identified, changes in cloud radiation, will produce either a positive feedback, if high level clouds are produced, or a negative feedback if low level clouds are produced. Few significant negative feedbacks have been identified, let alone quantified. Here, we show that the loss of ice shelves and retreat of coastal glaciers around the Antarctic Peninsula in the last 50 years has exposed at least 2.4 × 104 km2 of new open water. We estimate that these new areas of open water have allowed new phytoplankton blooms containing a total standing stock of ∼5.0 × 105 tonnes of carbon to be produced. New marine zooplankton and seabed communities have also been produced, which we estimate contain ∼4.1 × 105 tonnes of carbon. This previously unquantified carbon sink acts as a negative feedback to climate change. New annual productivity, as opposed to standing stock, amounts to 3.5 × 106 tonnes yr−1 of carbon, of which 6.9 × 105 tonnes yr−1 deposits to the seabed. By comparison the total aboveground biomasses of lowland American tropical rainforest is 160–435 tonnes ha−1. Around 50% of this is carbon. On this basis the carbon held in new biomass described here is roughly equivalent to 6000–17 000 ha of tropical rainforest. As ice loss increases in polar regions this feedback will become stronger, and eventually, over thousands to hundreds of thousands of years, over 50 Mtonnes of new carbon could be fixed annually in new coastal phytoplankton blooms and over 10 Mtonnes yr−1 locked in biological standing stock around Antarctica. [ABSTRACT FROM AUTHOR]

The Antarctic climate system varies on time-scales from orbital, through millennial to sub-annual, and is closely coupled to other parts of the global climate system. We review these variations from the perspective of the geological and glaciological records and the recent historical period from which we have instrumental data (∼the last 50 years). We consider their consequences for the biosphere, and show how the latest numerical models project changes into the future, taking into account human actions in the form of the release of greenhouse gases and chlorofluorocarbons into the atmosphere. In doing so, we provide an essential Southern Hemisphere companion to the Arctic Climate Impact Assessment. [ABSTRACT FROM AUTHOR]

Significant changes in physical and biological systems are occurring on all continents and in most oceans, with a concentration of available data in Europe and North America. Most of these changes are in the direction expected with warming temperature. Here we show that these changes in natural systems since at least 1970 are occurring in regions of observed temperature increases, and that these temperature increases at continental scales cannot be explained by natural climate variations alone. Given the conclusions from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report that most of the observed increase in global average temperatures since the mid-twentieth century is very likely to be due to the observed increase in anthropogenic greenhouse gas concentrations, and furthermore that it is likely that there has been significant anthropogenic warming over the past 50 years averaged over each continent except Antarctica, we conclude that anthropogenic climate change is having a significant impact on physical and biological systems globally and in some continents. [ABSTRACT FROM AUTHOR]

We analyze ensembles (four realizations) of historical and future climate transient experiments carried out with the coupled atmosphere-ocean general circulation model (AOGCM) of the Hadley Centre for Climate Prediction and Research, version HADCM2, with four scenarios of greenhouse gas (GHG) and sulfate forcing. The analysis focuses on the regional scale, and in particular on 21 regions covering all land areas in the World (except Antarctica). We examine seasonally averaged surface air temperature and precipitation for the historical period of 1961–1990 and the future climate period of 2046–2075. Compared to previous AOGCM simulations, the HADCM2 model shows a good performance in reproducing observed regional averages of summer and winter temperature and precipitation. The model, however, does not reproduce well observed interannual variability. We find that the uncertainty in regional climate change predictions associated with the spread of different realizations in an ensemble (i.e. the uncertainty related to the internal model variability) is relatively low for all scenarios and regions. In particular, this uncertainty is lower than the uncertainty due to inter-scenario variability and (by comparison with previous regional analyses of AOGCMs) with inter-model variability. The climate biases and sensitivities found for different realizations of the same ensemble were similar to the corresponding ensemble averages and the averages associated with individual realizations of the same ensemble did not differ from each other at the 5% confidence level in the vast majority of cases. These results indicate that a relatively small number of realizations (3 or 4) is sufficient to characterize an AOGCM transient climate change prediction at the regional scale. [ABSTRACT FROM AUTHOR]