Future Climate Trends Research Articles

Climate Change in Mediterranean Mountains during the 21st Century

Mediterranean mountain biomes are considered endangered due to climate change that affects directly or indirectly different key features (biodiversity, snow cover, glaciers, run-off processes, and water availability). Here, we provide an assessment of temperature, precipitation, and spring precipitation changes in Mediterranean mountains under different emission scenarios (Special Report on Emission Scenarios) and Atmosphere-Ocean-Coupled General Circulation Models for two periods: 2055 (2040-2069 period) and 2085 (2070-2099). Finally, the future climate trends projected for Mediterranean mountains are compared with those trends projected for non-Mediterranean European mountain ranges. The range of projected warming varies between +1.4 degrees C and 5.1 degrees C for 2055 (+1.6 degrees C and +8.3 degrees C for 2085). Climate models also project a reduction of precipitation, mainly during spring (-17% under Alfi and -4.8% under B1 for 2085). On the contrary, non-Mediterranean European mountains will not experience a reduction of annual and spring precipitation. Implications of predicted climate change for both human and physical features are coupled in an integrated framework to gain a broad perspective on future trends and their consequences.

Social Implications of Mobile Telephony: The Rise of Personal Communication Society

AbstractThe media landscape has changed dramatically in recent decades, from one predominated by traditional mass communication formats to today's more personalized network environment. Mobile communication plays a central role in this transition, with adoption rates that surpass even those of the Internet. This essay argues that the widespread diffusion and use of mobile telephony is iconic of a shift toward a new ‘personal communication society’, evidenced by several key areas of social change, including symbolic meaning of the technology, new forms of coordination and social networking, personalization of public spaces, and the mobile youth culture. The conclusion speculates on future trends in the sociotechnological climate.

Distribution of dinoflagellate cysts in surface sediments of the Mackenzie Shelf and Amundsen Gulf, Beaufort Sea (Canada)

In order to document long-term climate cycles and predict future climate trends for the Arctic, we need to look at the geological records to establish the link between historical and pre-historical sea-surface parameters. Dinoflagellate cysts (dinocysts) are used as proxy indicators of sea-surface parameters (temperature, salinity, sea-ice cover, primary productivity) jointly with transfer functions and a modern dinocyst reference database, to reconstruct the evolution of sea-surface conditions at decadal and millennial timescales. Here we present the surface distribution of recent dinocyst assemblages from 34 surface sediment samples collected on the Mackenzie Slope/Amundsen Gulf during the 2004 CASES (Canadian Arctic Shelf Exchange Study) cruise. Dinocyst concentrations in surface sediments are relatively high outside the Mackenzie plume area and increase gradually eastward toward Amundsen Gulf. The cysts of autotrophic dinoflagellates are dominant throughout the study area, while the maximum abundance of heterotrophic taxa is found within the Mackenzie plume. Hierarchical clustering analyses allowed defining two dinocyst assemblages. Assemblage I is located on the Mackenzie Slope and southern Amundsen Gulf, while Assemblage II is located within the Cape Bathurst Polynya area in northern Amundsen Gulf. Both assemblages are dominated by Operculodinium centrocarpum, but are distinguished on the basis of the relative abundance of Islandinium minutum, a taxon generally associated with sea ice. I. minutum is found in lower abundance in the Cape Bathurst Polynya.

On the Meteorological Instruments and Observations Made during the 19th Century Exploration of the Canadian Northwest Passage

Meteorological records from about 30 British Navy ships that overwintered in the Canadian Arctic islands between 1818 and 1859 are the earliest detailed baseline of direct historical data in this region against which modern and future climate trends can be assessed. We describe the types of meteorological instruments and the observational methods employed aboard these ships. For measuring air temperatures, both mercurial and spirit thermometers were used. Observations of atmospheric pressure were made using marine and aneroid barometers. Wind direction and speed were also logged. The Royal Navy’s ordered and disciplined daily regime was well-suited to regular scientific observations. Individual instruments on most Navy ships were calibrated against established Royal Observatory standards before and after expeditions. Many recording officers commented on the relative unreliability of spirit thermometers below the freezing point of mercury. Little contemporary written evidence exists regarding absolute accuracy or precision of meteorological instruments taken to the Arctic, but some calibration data are available to assess typical instrument errors between 32° and −38°F (0° and −39°C). Our comparison of minimum daily temperatures from four overwintering ships in 1853 and 1854 shows very high correlation coefficients. The mutual consistency of these records implies good instrumental precision. Although the absolute accuracy of temperatures recorded below the freezing point of mercury is in doubt, those above this point are relatively accurate. Guidance on the preferred methods of observing and recording were codified in, for example, the Admiralty’s Manual of Scientific Enquiry (Herschel, 1851). Meteorological registers were regarded as official documents that were, as far as possible, required to be complete and no attempt was to be made to fill in missing data. The need to screen or cover instruments from both solar and terrestrial radiation was also recognized from the earliest expeditions. It was not until the 1850s that standardizing the exposure of thermometers was resolved through the introduction of louvered screens. This unique set of ships’ meteorological registers presents opportunities to investigate a variety of meteorological parameters for the Canadian High Arctic in the 19th century, allowing quantitative assessment of change relative to contemporary climate.

Historical climate and stream flow trends and future water demand analysis in the Calgary region, Canada

The city of Calgary has been one of fastest growing cities in Canada in recent years. Rapid population growth and a warming climate trend have raised concerns about sustainable water supply. In this study, historic climate, stream flow and population data are analyzed in order to develop models of future climate trends and river-water resource availability. Daily water demands for the next 60 years were projected using the relationship between daily maximum temperature and water demand under simulated climate and population growth scenarios. To maintain sustainable growth Calgary will require water conservation efforts that reduce per capita water use to less than half of the current level over the next 60 years, an interval when the civic population is expected to be doubled.

Long‐term record of nss‐sulfate and nitrate in aerosols on Midway Island, 1981–2000: Evidence of increased (now decreasing?) anthropogenic emissions from Asia

Increasing anthropogenic emissions from Asia, especially from regions undergoing rapid industrial development, have raised interest in the outflow of chemically and radiatively important gases and aerosols. Previous studies have shown that high concentrations of Asian pollution spread over a broad region of the North Pacific every spring. Here we report on studies of aerosol concentrations at Midway Island (28°13′N, 177°22′W) in the central North Pacific over the period 1981–2000. Using a relatively simple procedure we estimate the natural and anthropogenic fractions of sulfate and nitrate aerosol and show that the estimated anthropogenic component almost doubled from 1981 to the mid‐1990s. This increase closely parallels estimates of increased emissions of SO2 from China. However, measurements in the late 1990s suggest that sulfate and nitrate concentrations have stabilized and perhaps decreased. Thus over the longer term pollution emissions from Asia and concentrations over the North Pacific may be less than earlier projections, a factor which has implications for the assessment of future climate trends.

The evolution of climate over the last millennium.

Knowledge of past climate variability is crucial for understanding and modeling current and future climate trends. This article reviews present knowledge of changes in temperatures and two major circulation features-El Niño-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO)-over much of the last 1000 years, mainly on the basis of high-resolution paleoclimate records. Average temperatures during the last three decades were likely the warmest of the last millennium, about 0.2 degrees C warmer than during warm periods in the 11th and 12th centuries. The 20th century experienced the strongest warming trend of the millennium (about 0.6 degrees C per century). Some recent changes in ENSO may have been unique since 1800, whereas the recent trend to more positive NAO values may have occurred several times since 1500. Uncertainties will only be reduced through more extensive spatial sampling of diverse proxy climatic records.

The IPCC Third Assessment Report on the Scientific Basis of Climate Change

The Intergovernmental Panel on Climate Change (IPCC) has recently completed its Third Assessment Report on the Scientific Basis of Climate Change. The report builds on previous IPCC assessment reports in 1990 and 1995 and has been in preparation for the past three and a half years through the work of more than 500 scientists world wide who have been taking stock of the research findings reported in some 4000 peer—reviewed scientific papers. The report consists of a Summary for Policymakers, a Technical Summary and an underlying detailed report of fourteen chapters. The Summary for Policymakers was approved on a line by line basis by an intergovernmental session of the science working group (Working Group 1) of the IPCC, held in Shanghai, China on 17–20 January 2001, with the participation of some 45 of the 122 Lead Authors and official government delegations from 99 countries. The report concludes that, although many uncertainties remain, the past five years of observations and research have provided stronger evidence than hitherto of a human impact on global climate and increased confidence in the capability of climate models to project future global climate trends for a range of emission scenarios through the twenty first century. This article, which is based, in part, on the author's experience as Principal Delegate of Australia to the IPCC and as a member of the IPCC Bureau since 1994, describes the operation of the IPCC assessment process and the preparation, approval and main conclusions of the science component of the Third Assessment Report.

Climatological coupling of the thermohaline decadal changes in Central Water of the Eastern North Atlantic

Data collected at 42oN, 10oW in the intergyre region of the Northeast Atlantic show significant year to year variability in the T-S characteristics of the upper 800m of the water column. Taking salinity values on the sq = 27.1 kg m-3 isopycnal as representative of the Eastern North Atlantic Central Water mass it was found that the variability correlates well with the wind stress at 43oN, 11oW, with cumulative river discharge (which we take as an index of precipitation over the ocean) and with the NAO (which is an index of the strength and position of storm tracks and the state of the evaporation-precipitation balance). The covariation illustrates the close coupling between water mass formation and climate in the North Atlantic, where climate changes affect the deep ventilation by which ENACW is formed and the evaporation-precipitation balance from which the T-S signature results. Hints of a 20 year cycle in the ocean correlate with a 20 year periodicity in the NAO. It remains to be established whether there is a feedback mechanism by which water mass anomalies affect the climate and the intensity and variation of the NAO pattern, and the extent to which upper ocean observations can be used as an indicator of future climate trends.

Natural climatic variability as an explanation for historical climatic fluctuations

The question as to whether the climatic anomalies associated with the Medieval Warm Period and the Little Ice Age can be attributed to natural climatic variability is explored in this paper. The output from a 500-year run with a global climatic model is used for this purpose. The model exhibits multi-decadal variability in its climatic outputs, which appears to have many of the characteristics of observed climatic data over the last millennium. Global distributions of surface temperature associated with peak warming and cooling phases of the model run highlight the spatial variability which occurs, and the lack of synchroneity in the response from region to region. Considerable year-to-year variability occurs in temperature anomaly patterns during the warming and cooling phases, indicating the complexity of the responses. The model results suggest that such climatic phases should not be considered as lengthy periods of universal warming or cooling. Comparison of observed time series of land surface temperature for the northern hemisphere for the last 500 years with model output indicates that most of the observed features in this climatic record can be reproduced by processes associated with internal mechanisms of the climatic system as reproduced in the model. While the model results do not exclude the possible contribution of external forcing agents as a contributing factor to these climatic episodes, the perception is that such agents would enhance existing naturally-induced climatic features rather than initiate them, at least for this time frame. Given the omnipresent nature of natural climatic variability, it is assumed that such variability rather than external forcing agents has primacy in generating and maintaining the underlying observed climatic variability. An understanding of the mechanisms and behaviour of such climatic features is becoming of increasing importance, in view of their possible role in modulating future climatic trends given the expected influence of the greenhouse effect.

Analysis of climate scenarios for Bolivia

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 09:115-120 (1997) - DOI: https://doi.org/10.3354/cr009115 Analysis of climate scenarios for Bolivia Oscar Paz Rada*, Sergio Romero Crespo, Freddy Tejada Miranda Ministerio de Desarrollo Sostenible y Planificación, Viceministerio de Desarrollo Sostenible y Medio Ambiente, Dirección General de Medio Ambiente, Políticas y Normas, Programa Nacional de Cambios Climáticos, Plaza España esq. Méndez Arcos N° 710, PO Box 1508, La Paz, Bolivia *E-mail: pncambio@clima.rds.org.bo This paper presents a preliminary description of a study carried out in Bolivia to develop scenarios of climate change resulting from radiative forcing and produced by means of stabilized and transient General Circulation Models (GCMs). These models are valuable tools for simulating the physical processes which determine global climate. A variety of climates are present in Bolivia as a result of the country's physical characteristics, particularly altitude. The country is largely influenced by air masses from the north (Equatorial Amazon Current) and from the south (Austral Current). Therefore, to define a single and homogeneous scenario for the entire country is a particularly difficult task. Temperature and precipitation records from more than 20 weather stations located within the 3 main river basins of the country (Amazon Basin, 'Altiplano' Basin and Plata Basin) were graphically compared with GCM outputs under 1×CO2 conditions. The GCMs used were GISS, UK89, CCCM and GFDL R-30. The models which best fit the actual values were identified in order to determine the expected temperature and precipitation variations under a doubled atmospheric carbon dioxide concentration condition (2×CO2). In the case of Bolivia it was observed that the models providing the best fit were the GISS and the UK89, together with the GFDL 1% transient model; these were thus selected to develop the climate change scenarios describing possible future trends in climate. Bolivia · Climate · Climate Change · Climate scenarios · General Circulation Models Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 09, No. 1-2. Publication date: December 29, 1997 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 1997 Inter-Research.

Disaggregation Modeling Process for Climatic Time Series

To assess the potential effects of climatic changes on water resources, it is important to incorporate predictions of future climatic trends into hydrologic planning models. Disaggregation models can be used to produce a time series at one resolution from a parent series at a different scale. In this study, a disaggregation approach is used to generate a time series simulating surface air temperature and precipitation. An annual series is generated using a 70-year record from Sacramento, California, and each year is disaggregated into 24 seasonal values. The output series from this modeling process are compared with the historical record. It is found that the statistical and correlation characteristics of the historical series are well maintained. The synthetic and historical series are applied to a reservoir-sizing model, and optimal reservoir sizes are found to be statistically similar. The results indicate the potential usefulness of this technique for generating synthetic temperature and precipitation to use in hydrologic planning based on future climate scenarios.

Short-term climate change and New Zealand temperatures during the last millennium

MANY theories have been proposed to explain the climatic fluctuations which produced the sequence of glacial–interglacial periods of the order of tens of thousands of years which have occurred throughout the Quaternary. These fluctuations represent temperature changes in the temperate regions of about 6 °C between a glacial and an interglacial situation. There are also climatic fluctuations with a period of the order of about a thousand years representing temperature changes of about 2 °C. These changes are believed to have had an important bearing on human history, but have been little studied because it is difficult to obtain accurate temperature records for past periods. Shorter temperature fluctuations of the order of a few decades, and representing temperature changes of perhaps as much as one degree, are of considerable economic importance and merge into the developing field of long-term meteorological forecasting. Considerable interest has recently developed in short-term climate changes. If detailed long-term climatic records could be obtained for extended periods in the past it might be possible to determine the causes for the climatic variation, and hence predict future climate trends. Even a knowledge of how hot/cold or dry/wet a particular region's climate could become, and with what probability, would be of considerable economic value to planners involved in hydroelectric development, irrigation schemes, snow clearance and the development of arid and polar regions. At present instrumental records have existed only since the mid-seventeenth century for central England, and for most other areas only over a little more than a century. Cave deposits (speleothems) provide stratigraphy which has a high inherent time resolution. Data for studying short-term temperature fluctuations can be obtained by measuring the 18O/16O ratio of suitable stalagmites1. This technique should enable a high resolution temperature curve to be produced for many regions of the globe. We report here an investigation on the 18O/16O profile through a New Zealand stalagmite which was undertaken partly to evaluate the feasibility of obtaining high time resolution data from speleothem material and partly to compare the temperature record from New Zealand (in the Southern Hemisphere and a region meteorologically unrelated to Europe) with the English climate curve, which is the most firmly established climate curve for the last millennium. Such proxy data given us the possibility of obtaining long-term high resolution temperature records from some of the critical regions of the world where meteorological records either do not exist or are of very short duration.

Cyclic climatic variations in climate over the past 5,500 yr reflected in raised bogs

Investigations of Danish raised bogs apparently indicate cyclic long term climatic variations with a periodicity of about 260 yr over the past 5,500 yr. The result could be used for modelling future climatic trends.