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At least 37 records · Page 2Linked to original sources

PubMed2006

Modelling species' range shifts in a changing climate: the impacts of biotic interactions, dispersal distance and the rate of climate change.

There is an urgent need for accurate prediction of climate change impacts on species ranges. Current reliance on bioclimatic envelope approaches ignores important biological processes such as interactions and dispersal. Although much debated, it is unclear how such processes might influence range shifting. Using individual-based modelling we show that interspecific interactions and dispersal ability interact with the rate of climate change to determine range-shifting dynamics in a simulated community with two growth forms--mutualists and competitors. Interactions determine spatial arrangements of species prior to the onset of rapid climate change. These lead to space-occupancy effects that limit the rate of expansion of the fast-growing competitors but which can be overcome by increased long-distance dispersal. As the rate of climate change increases, lower levels of long-distance dispersal can drive the mutualists to extinction, demonstrating the potential for subtle process balances, non-linear dynamics and abrupt changes from species coexistence to species loss during climate change.

Animals↗

PubMed2000

Influence of mean climate change on climate variability from a 155-year tropical Pacific coral record.

Today, the El Niño/Southern Oscillation (ENSO) system is the primary driver of interannual variability in global climate, but its long-term behaviour is poorly understood. Instrumental observations reveal a shift in 1976 towards warmer and wetter conditions in the tropical Pacific, with widespread climatic and ecological consequences. This shift, unique over the past century, has prompted debate over the influence of increasing atmospheric concentrations of greenhouse gases on ENSO variability. Here we present a 155-year ENSO reconstruction from a central tropical Pacific coral that provides new evidence for long-term changes in the regional mean climate and its variability. A gradual transition in the early twentieth century and the abrupt change in 1976, both towards warmer and wetter conditions, co-occur with changes in variability. In the mid-late nineteenth century, cooler and drier background conditions coincided with prominent decadal variability; in the early twentieth century, shorter-period (approximately 2.9 years) variability intensified. After 1920, variability weakens and becomes focused at interannual timescales; with the shift in 1976, variability with a period of about 4 years becomes prominent. Our results suggest that variability in the tropical Pacific is linked to the region's mean climate, and that changes in both have occurred during periods of natural as well as anthropogenic climate forcing.

Animals↗

PubMed2005

Chemistry-climate coupling: the importance of chemistry in climate issues.

Chemistry plays an important role in determining the current state and the predictions of the future state of earth's climate because a large number of agents that force earth's climate are chemically active. Chemical processes in the atmosphere determine the abundances and properties of atmospheric forcing agents. This is particularly true for the species that need to be addressed for influencing the course of the earth's climate in the near future. The factors that determine the chemical transformations and properties of chemically active climate forcing agents are discussed here. The levels of improvements needed in our understanding of chemical processes to reduce the uncertainties in the climate forcing are noted. The specific issues of night time chemistry, non-linear chemical processes, parameterization of atmospheric processes, spatial/temporal variability of chemical species, and the need for real world characterization of aerosols are discussed.

Aerosols↗

PubMed2002

Herbivory, plant resistance, and climate in the tree ring record: interactions distort climatic reconstructions.

To understand climate change, dendrochronologists have used tree ring analyses to reconstruct past climates, as well as ecological processes such as herbivore population dynamics. Such reconstructions, however, have been hindered by a lack of experiments that separate the influences of confounding impacts on tree rings, such as herbivores and the interactions of multiple factors. Our long-term experiments with scale insects on resistant and susceptible pines demonstrate three major points that are important to the application of this commonly used tool. (i) Herbivory reduced tree ring growth by 25-35%. (ii) The impact on ring growth distorted climate reconstruction, resulting in the overestimation of past moisture levels by more than 2-fold. Our data suggest that, if distortion because of herbivory has been a problem in previous reconstructions, estimates of the magnitude of recent climate changes are likely to be conservative. (iii) Our studies support a detectible plant resistance x herbivore x climate interaction in the tree ring record. Because resistance and susceptibility to herbivory are known to be genetically based in many systems, the potential exists to incorporate plant genetics into the field of dendrochronology, where it may be used to screen distortions from the tree ring record.

Animals↗

PubMed2000

Impacts of climate and climate change on medications and human health.

OBJECTIVE: To examine impacts of climate and climate change on medications and human health. METHODS: Literature review and analysis of MIMS. RESULTS: Changed climate associated with the enhanced Greenhouse Effect (e.g. increased temperature) may lead to medication-related health impacts through deterioration of storage conditions, increased heat stress from medication-induced heat intolerance, and by influencing pharmacokinetics. Increases in UV radiation from stratospheric ozone depletion may increase the significance of medications that can lead to an increased sensitivity to the damaging effects of UV radiation (i.e. photosensitivity). CONCLUSIONS AND IMPLICATIONS: Raising awareness of the impacts of climate on medications, and of climate-related side-effects, among both health care professionals and the public, should modify behaviour and therefore reduce the risks of such adverse impacts.

Climate↗

PubMed2004

Effects of changes in climate on landscape and regional processes, and feedbacks to the climate system.

Biological and physical processes in the Arctic system operate at various temporal and spatial scales to impact large-scale feedbacks and interactions with the earth system. There are four main potential feedback mechanisms between the impacts of climate change on the Arctic and the global climate system: albedo, greenhouse gas emissions or uptake by ecosystems, greenhouse gas emissions from methane hydrates, and increased freshwater fluxes that could affect the thermohaline circulation. All these feedbacks are controlled to some extent by changes in ecosystem distribution and character and particularly by large-scale movement of vegetation zones. Indications from a few, full annual measurements of CO2 fluxes are that currently the source areas exceed sink areas in geographical distribution. The little available information on CH4 sources indicates that emissions at the landscape level are of great importance for the total greenhouse balance of the circumpolar North. Energy and water balances of Arctic landscapes are also important feedback mechanisms in a changing climate. Increasing density and spatial expansion of vegetation will cause a lowering of the albedo and more energy to be absorbed on the ground. This effect is likely to exceed the negative feedback of increased C sequestration in greater primary productivity resulting from the displacements of areas of polar desert by tundra, and areas of tundra by forest. The degradation of permafrost has complex consequences for trace gas dynamics. In areas of discontinuous permafrost, warming, will lead to a complete loss of the permafrost. Depending on local hydrological conditions this may in turn lead to a wetting or drying of the environment with subsequent implications for greenhouse gas fluxes. Overall, the complex interactions between processes contributing to feedbacks, variability over time and space in these processes, and insufficient data have generated considerable uncertainties in estimating the net effects of climate change on terrestrial feedbacks to the climate system. This uncertainty applies to magnitude, and even direction of some of the feedbacks.

Arctic Regions↗

PubMed2003

[Assessment of eco-climatic suitability and climate change impacts of/on broad-leaved Korean pine forest in northeast China].

Based on growing degree days (GDD) and potential evapotranspiration ratio (PER), the temperature-water effect function (f(GDD, PER)) was established and the assessment of eco-climatic suitability and climate change impacts of/on broadleaved Korean pine forests in Northeast China was studied. The results showed that the present distribution area of broad-leaved Korean pine forests in Northeast China was 39.99 km2, which included the optimum distribution area 7.13 km2, suitable area 12.27 km2, and marginal area 20.59 km2. Under GISS and OSU climate change scenarios, the climate of Northeast China changed to warming and dry in some degree. Under this tendency, the distribution area of broad-leaved Korean pine forests would be reduced, and the eco-climatic suitability would be declined.

Carbon Dioxide↗

PubMed2004

The Rossby Centre Regional Atmospheric Climate Model part I: model climatology and performance for the present climate over Europe.

The Rossby Centre Atmospheric Regional Climate Model (RCA2) is described and simulation results, for the present climate over Europe, are evaluated against available observations. Systematic biases in the models mean climate and climate variability are documented and key parameterization weaknesses identified. The quality of near-surface parameters is investigated in some detail, particularly temperature, precipitation, the surface energy budget and cloud cover. The model simulates the recent, observed climate and variability with a high degree of realism. Compensating errors in the components of the surface radiation budget are highlighted and the fundamental causes of these biases are traced to the relevant aspects of the cloud, precipitation and radiation parameterizations. The model has a tendency to precipitate too frequently at small rates, this has a direct impact on the simulation of cloud-radiation interaction and surface temperatures. Great care must be taken in the use of observations to evaluate high resolution RCMs, when they are forced by analyzed boundary conditions. This is particularly true with respect to precipitation and cloudiness, where observational uncertainty is often larger than the RCM bias.

Atmosphere↗

PubMed1982

[Comparative studies of climatic factors effecting the performance of cattle in different climatic zones of Egypt].

In continuation of previous analogous studies on climatic factors influencing the performance of cattle in Northern Egypt (climate types III4a/IV: etesian climate of the Mediterranean type) the present investigation deals with the temperature and humidity for Southern Egypt (climate type III1; arid, subtropical desert climate) and classifies them according to the physiological tolerability ranges set up for cattle. In Northern Egypt (Maryut) 23.8% of the temperatures were beyond the optimum and physiologically still tolerable range (0 to 24 degrees C) and were thus in the intolerable range; 45.8% were within the optimum tolerability range. In Southern Egypt (El Menia) 46.7% were within the intolerable range and only 25.7% in the optimum range (5 to 18 degrees C). The relative humidity values had 21.9% within the optimum range and 63.9% in the intolerable range in the North; in the South 22.9% were within the optimum and 55.5% in the intolerable range.

Acclimatization↗

PubMed2001

Rapid changes of glacial climate simulated in a coupled climate model.

Abrupt changes in climate, termed Dansgaard-Oeschger and Heinrich events, have punctuated the last glacial period (approximately 100-10 kyr ago) but not the Holocene (the past 10 kyr). Here we use an intermediate-complexity climate model to investigate the stability of glacial climate, and we find that only one mode of Atlantic Ocean circulation is stable: a cold mode with deep water formation in the Atlantic Ocean south of Iceland. However, a 'warm' circulation mode similar to the present-day Atlantic Ocean is only marginally unstable, and temporary transitions to this warm mode can easily be triggered. This leads to abrupt warm events in the model which share many characteristics of the observed Dansgaard-Oeschger events. For a large freshwater input (such as a large release of icebergs), the model's deep water formation is temporarily switched off, causing no strong cooling in Greenland but warming in Antarctica, as is observed for Heinrich events. Our stability analysis provides an explanation why glacial climate is much more variable than Holocene climate.

Journal Article↗

PubMed2002

Constraints on radiative forcing and future climate change from observations and climate model ensembles.

The assessment of uncertainties in global warming projections is often based on expert judgement, because a number of key variables in climate change are poorly quantified. In particular, the sensitivity of climate to changing greenhouse-gas concentrations in the atmosphere and the radiative forcing effects by aerosols are not well constrained, leading to large uncertainties in global warming simulations. Here we present a Monte Carlo approach to produce probabilistic climate projections, using a climate model of reduced complexity. The uncertainties in the input parameters and in the model itself are taken into account, and past observations of oceanic and atmospheric warming are used to constrain the range of realistic model responses. We obtain a probability density function for the present-day total radiative forcing, giving 1.4 to 2.4 W m-2 for the 5-95 per cent confidence range, narrowing the global-mean indirect aerosol effect to the range of 0 to -1.2 W m-2. Ensemble simulations for two illustrative emission scenarios suggest a 40 per cent probability that global-mean surface temperature increase will exceed the range predicted by the Intergovernmental Panel on Climate Change (IPCC), but only a 5 per cent probability that warming will fall below that range.

Journal Article↗

PubMed2004

[Measuring workplace climate: reliability and validity of the 12-item Organizational Climate Scale (OCS-12)].

In order to investigate the reliability and validity of the short version of the 30-item Organizational Climate Scale (OCS-30; Toshima and Matsuda, 1992, 1995), a self-administered questionnaire was conducted in a sample of 819 employees of two medium-sized private companies in Japan by using the OCS-30, the Generic Job Stress Questionnaire (GJSQ), and the 12-item General Health Questionnaire (GHQ-12). The OCS has two subscales, i.e., the Tradition Scale (TS) and the Organizational Environment Scale (OES). The organizational climate perceived by each worker can be grouped into four categories based on the subscale scores: low TS and high OES (Active), high TS and high OES (Governed), low TS and low OES (Disorganized), and high TS and low OES (Reluctant). Principal component analysis for the OCS-30 was submitted (varimax rotation, the number of factors = 2), and 6 items for each factor, with factor loadings greater than 0.50, were selected for the short version, which constituted the 12-item Organizational Climate Scale (OCS-12). Cronbach's alpha reliability coefficients of the two subscales of the OCS-12 were acceptable; 0.63 for the TS and 0.71 for the OES. Both two subscales of the OCS-12 were significantly correlated with the GHQ-12 and many subscales of the GJSQ, which indicated the good constructive validity of the OCS-12. Among 4 types of organizational climate categorized by the OCS-12, the "Active" group showed the lowest job stress scores. It is suggested that the OCS-12 could be a reliable and valid instrument for assessing workers' perception of workplace climate.

Adult↗

PubMed2002

The influence of land-use change and landscape dynamics on the climate system: relevance to climate-change policy beyond the radiative effect of greenhouse gases.

Our paper documents that land-use change impacts regional and global climate through the surface-energy budget, as well as through the carbon cycle. The surface-energy budget effects may be more important than the carbon-cycle effects. However, land-use impacts on climate cannot be adequately quantified with the usual metric of 'global warming potential'. A new metric is needed to quantify the human disturbance of the Earth's surface-energy budget. This 'regional climate change potential' could offer a new metric for developing a more inclusive climate protocol. This concept would also implicitly provide a mechanism to monitor potential local-scale environmental changes that could influence biodiversity.

Agriculture↗

PubMed2003

Climate perceptions matter: a meta-analytic path analysis relating molar climate, cognitive and affective states, and individual level work outcomes.

Although workplace climate has been extensively studied, the research has not led to firm conclusions as to its relationship with individual level work outcomes. The authors used C. Ostroff's (1993) taxonomy to organize dimensions labeled as workplace climate and then used meta-analytic techniques to test a path analytic model. The model posited that climate affects individual level outcomes through its impact on underlying cognitive and affective states. An extensive literature search yielded 51 empirical studies with 70 samples. The results suggest that the 3 higher order facets of climate (affective, cognitive, and instrumental) affected individual level outcomes of job performance, psychological well-being, and withdrawal through their impact on organizational commitment and job satisfaction.

Affect↗

PubMed2001

Impacts of climate change and climate variability on the competitiveness of wheat and beef cattle production in Emerald, north-east Australia.

Emerald, north-east Queensland, is at the northern margin of the wheat cropping region of Australia. The Emerald region was previously used predominantly for grazing beef cattle; however, cropping has developed in importance over the past 30 years. We use historical climate records (1890-1998) to simulate and compare wheat yields, grass production and live-weight gain (LWG) over time. The cropping expansion from the 1970s to the early 1990s has occurred in a unique period in the 108-year record with the highest average wheat yields, lowest wheat yield variability and the greatest relative productivity of wheat production against grass production. If this window of opportunity is a result of long-term climate variability, then cropping is likely to decline in the region as conditions return to those experienced earlier in the record. If this increase is related to climate change, then cropping is likely to persist in the region with productivity maintained at current levels particularly through the yield-enhancing effects of increased atmospheric CO2 concentrations. However, this persistence will be influenced by the frequencies of El Niño conditions that may increase with global warming. The high relative productivities experienced over the past few decades have probably biased producers' expectations, and applications for drought support need to take into account the longer-term perspective provided by this analysis. Nevertheless, the last 6 years have the lowest simulated mean LWG production on the record. The identification of poor production periods depended on the production element being addressed and the timescale involved.

Agriculture↗

PubMed2005

The crisis of the thesis of climatic pessimism: malaria and the climatic question.

The publication of Boudin's Traité de Geographie et de Statistique médicale (1857) and the creation in 1908 of the Institut de Pathologie Exotique by Laveran, correspond to two entirely different manners of considering tropical diseases and adaptability (or acclimatation) to the Tropics, directly associated with the idea of capability or incapability of Europeans to resist tropical diseases. We analyse the way perspectives have changed with respect to the influence that climate, particularly tropical, exert on the body of individuals and on populations used to live under temperate climatic conditions. The manner the concepts of medical geography, climatic pessimism and individual acclimatation get articulated with the discovery of tropical diseases, their aetiological agents and their localisation, particularly malaria, can only be understood by also analysing how the problems generated by the diversity of races and migration phenomena have been envisaged.

Adaptation, Physiological↗

PubMed1981

[Comparative studies of climatic conditions and the effect of climate in the Socialist Republic of Vietnam and in the People's Republic of Bulgaria on the microclimate in housing for commercial poultry breeding].

Comparative studies were carried out on the climate aspects in the Socialist Republic of Vietnam and the People's Republic of Bulgaria. Tested was the effect of the typical tropic and the typical continental climate in buildings for the industrial raising of birds. Data were provided of the solar radiation and the temperature and moisture characteristics of the climate in the two countries. On the basis of these studies and the results obtained in the raising of broilers concrete suggestions were made to optimize the technology of bird raising in Vietnam.

Animals↗

PubMed1993

Measuring the climate for health at organizations. Development of the worksite health climate scales.

Worksite health promotion research has overemphasized the impact of individual behaviors on employee well-being and neglected the important influence of the work environment. In the present research effort, measures of the health climate at the worksite were developed, administered to employees at a newspaper company, and then tested for their psychometric properties. After revising the original scales, several health outcome variables and an improved version of the measure were administered to employees at seven small worksites. The results indicated that the health climate differed significantly across worksites and that health climate perceptions were significantly related to measures of physical symptoms; exercise, nutrition, and smoking habits; job stress; and job satisfaction.

Exercise↗