Abstracts on Global Climate Change

Jun 2006

Regional climate change and its effects on river runoff in the Tarim Basin, China

Chen, YN Takeuchi, K Xu, CC Chen, YP Xu, ZX


The hydrological response to climate change in the Tarim River Basin was investigated by analysing the hydrological. temperature and precipitation data of the past 50 years. The long-term trend of the hydrological time-series, including air temperature, precipitation, and streamflow, was examined by using both parametric and non-parametric techniques and the plausible association between streamflow and climate change by the method of are), correlation analysis. The results show that the study area became warmer in the last few decades. The air temperature experienced a significant monotonic increase by 5%; the precipitation showed a significant decrease in the 1970s and then a major increase in the 1980s and 1990s, with average annual precipitation up by 6.8 nun per decade. A step change occurred in both temperature and precipitation around 1986, with mean temperature and precipitation increasing from 6.7 degrees C and 146 mm before 1986 to 7.3 degrees C and 180 mm respectively after 1986. The temperature has risen by nearly 1 degrees C over the past 50 years, possibly resulting from the impact of global climate change. Streamflows in the Aksu River and the Yarkant River have shown a significant (P < 0.05) tendency of increase. This is particularly the case for the Aksu River. The coefficients of streamflow increase in the Aksu and Yarkant Rivers are 0.41 and 0.13 respectively. The results of grey correlation analysis show that in the Aksu River. which is located in the northwest of the basin, the impact of precipitation on streamflow is much greater than that of temperature. However, in the Hotan River, which is located in the southwest of the basin, the impact of temperature on streamflow is much greater than that of precipitation. This is likely to be related to the geographic distribution of the headstreams of the rivers. Copyright (C) 2006 John Wiley & Sons, Ltd.

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Rapid advance of spring arrival dates in long-distance migratory birds

Jonzen, N Linden, A Ergon, T Knudsen, E Vik, JO Rubolini, D Piacentini, D Brinch, C Spina, F Karlsson, L Stervander, M Andersson, A Waldenstrom, J Lehikoinen, A Edvardsen, E Solvang, R Stenseth, NC

SCIENCE 312:5782 1959-1961

Several bird species have advanced the timing of their spring migration in response to recent climate change. European short-distance migrants, wintering in temperate areas, have been assumed to be more affected by change in the European climate than long-distance migrants wintering in the tropics. However, we show that tong-distance migrants have advanced their spring arrival in Scandinavia more than short-distance migrants. By analyzing a long-term data set from southern Italy, we show that long-distance migrants also pass through the Mediterranean region earlier. We argue that this may reflect a climate-driven evolutionary change in the timing of spring migration.

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Variation in the sensitivity of organismal body temperature to climate change over local and geographic scales

Gilman, SE Wethey, DS Helmuth, B


Global climate change is expected to have broad ecological consequences for species and communities. Attempts to forecast these consequences usually assume that changes in air or water temperature will translate into equivalent changes in a species’ organismal body temperature. This simple change is unlikely because an organism’s body temperature is determined by a complex series of interactions between the organism and its environment. Using a biophysical model, validated with 5 years of field observations, we examined the relationship between environmental temperature change and body temperature of the intertidal mussel Mytilus califomianus over 1,600 km of its geographic distribution. We found that at all locations examined simulated changes in air or water temperature always produced less than equivalent changes in the daily maximum mussel body temperature. Moreover, the magnitude of body temperature change was highly variable, both within and among locations. A simulated 1 degrees C increase in air or water temperature raised the maximum monthly average of daily body temperature maxima by 0.07-0.92 degrees C, depending on the geographic location, vertical position, and temperature variable. We combined these sensitivities with predicted climate change for 2100 and calculated increases in monthly average maximum body temperature of 0.97-4.12 degrees C, depending on location and climate change scenario. Thus geographic variation in body temperature sensitivity can modulate species’ experiences of climate change and must be considered when predicting the biological consequences of climate change.

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Regional climate change and its impact on photooxidant concentrations in southern Germany: Simulations with a coupled regional climate-chemistry model

Forkel, R Knoche, R


[ 1] In order to investigate possible effects of global climate change on the near-surface concentrations of photochemical compounds in southern Germany, nested regional simulations with a coupled climate-chemistry model were carried out. The simulations with a horizontal resolution of 60 km for Europe and 20 km for central Europe were driven by meteorological boundary conditions provided by a long-term simulation of the global climate model ECHAM4. Two time slices of about 10 years were compared, one representing the 1990s and one representing the 2030s. For the region of southern Germany the simulations show an increase of the mean summer temperature by almost 2 degrees along with a decrease of cloud water and ice and a corresponding increase of the photolysis frequencies and the emissions of biogenic hydrocarbons. Under the model assumption of unchanged anthropogenic emissions this leads to an increase of the mean mixing ratios of most photooxidants. Because of the complex topography and the heterogeneous distribution of precursor emissions all parameters show pronounced regional patterns. The average daily maximum ozone concentrations in southern Germany increase for the considered scenario by nearly 10% in the summer months. Depending on the region, the increase of the mean daily maximum ranges between 2 and 6 ppb. As a consequence, the number of days when the 8-hour mean of the ozone concentration exceeds the threshold value of 120 mu g m(-3) increases by 5 to 12 days per year.

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Scaling the metabolic balance of the oceans

Lopez-Urrutia, A San Martin, E Harris, RP Irigoien, X


Oceanic communities are sources or sinks of CO2, depending on the balance between primary production and community respiration. The prediction of how global climate change will modify this metabolic balance of the oceans is limited by the lack of a comprehensive underlying theory. Here, we show that the balance between production and respiration is profoundly affected by environmental temperature. We extend the general metabolic theory of ecology to the production and respiration of oceanic communities and show that ecosystem rates can be reliably scaled from theoretical knowledge of organism physiology and measurement of population abundance. Our theory predicts that the differential temperature-dependence of respiration and photosynthesis at the organism level determines the response of the metabolic balance of the epipelagic ocean to changes in ambient temperature, a prediction that we support with empirical data over the global ocean. Furthermore, our model predicts that there will be a negative feedback of ocean communities to climate warming because they will capture less CO2 with a future increase in ocean temperature. This feedback of marine biota will further aggravate the anthropogenic effects on global warming.

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Winds of change?: Projections of near-surface winds under climate change scenarios

Pryor, SC Schoof, JT Barthelmie, RJ


Changes in near - surface wind speeds due to global climate change may have profound geophysical and societal impacts. However, Global Climate Models (GCMs) are unable to replicate the historically observed magnitude and spatial variability of wind speeds, so we apply a downscaling technique to generate probability distributions of wind speeds at sites in northern Europe for historical periods ( 1961 - 1990 and 1982 - 2000) and two future periods ( 2046 - 2065, 2081 - 2100). Projections for the twenty-first century (C21st) indicate no evidence of substantial evolution relative to the end of the twentieth century (C20th), although there is increased divergence of results from downscaling of different GCMs toward the end of C21st. Predicted changes in the downscaled mean and 90th percentile wind speeds are small (< +/- 15%) and are comparable to the current variability manifest in downscaling from different GCMs.

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Options and instruments for a deep cut in CO2 emissions: Carbon dioxide capture or renewables, taxes or subsidies?

Gerlagh, R Van der Zwaan, B


This paper compares both the main physical options and the principal policy instruments to realize a deep cut in carbon dioxide emissions necessary to control global climate change. A top-down energy-economy model is used that has three emission reduction options: energy savings, a transition towards less-carbon-intensive or non-carbon energy resources, and the use of carbon dioxide capture and storage technology. Five policy instruments - carbon taxes, fossil fuel taxes, non-carbon (renewable) energy subsidies, a portfolio standard for the carbon intensity of energy production, and a portfolio standard for the use of non-carbon (renewable) energy resources - are compared in terms of costs, efficiency and their impact on the composition of the energy supply system. One of our main conclusions is that a carbon intensity portfolio standard, involving the recycling of carbon taxes to support renewables deployment, is the most cost-efficient way to address the problem of global climate change. A comprehensive introduction of the capture and storage of carbon dioxide would contribute to reducing the costs of climate change control, but would not obviate the large-scale need for renewables.

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Durability design of infrastructure and some related issues

Mirza, S


The life cycle performance of any infrastructure should be taken into consideration in its design, its construction, its maintenance, its operation, and when needed, its rehabilitation. The protection of infrastructure must be holistic, taking into account long-term socioeconomic and environmental considerations and the impact of the global climate change. Fulfilling the requirements of the ultimate and serviceability limit states over the service life of the facility requires an understanding of the use of the system, the deterioration response of the materials and their components when subjected to aggressive environments, and how this deterioration can be prevented or significantly delayed by preventive, remedial, and routine maintenance. The composition, microstructure, macrostructure, and various modes of deterioration of materials used in construction (steel, wood, concrete) are reviewed, along with possible remedial measures. The development of concrete as a construction material, its durability, and the relevant durability provisions in the various Canadian Standards Association standards are reviewed briefly. Current European practice and the 1990 Comite Euro-International du beton Design Guide for Durable Concrete Structures are evaluated. The engineer’s responsibility for durable performance of a facility and the importance of durability audits are also examined.

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Life at the edge: an experimental study of a poleward range boundary

Gilman, SE

OECOLOGIA 148:2 270-279

Experimental studies of biogeographic processes are important, but rarely attempted because of the logistical challenges of research at large spatial scales. I used a series of large-scale transplant experiments to investigate the mechanisms controlling species abundance near a poleward range boundary. The intertidal limpet Collisella scabra experiences a 100-fold decline in abundance over the northernmost 300 km of its range. Temperature and food supply both strongly influenced individual survival, growth, and maturation. Regression analysis also revealed significant interactions among these conditions: the effect of one could not be predicted without knowing the level of the other. But these relationships could not explain geographic abundance patterns. Instead, individual limpets were highly successful at sites with relatively low abundance. These results suggest that, even though temperature is important to the success of individual C. scabra populations, the primary effect of warming temperatures under climate change may not be a shift in geographic distribution.

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Changes in occurrence and abundance of northern/southern flatfishes over a 20-year period in a coastal nursery area (Bay of Vilaine) and on the eastern continental shelf of the Bay of Biscay

Desaunay, Y Guerault, D Le Pape, O Poulard, JC

SCIENTIA MARINA 70: Suppl. 1 193-200

Several works have demonstrated trends in the distribution of fish species relative to global warming. This study investigated whether similar trends have occurred for selected flatfish species on the continental shelf of the Bay of Biscay. These species were used as indicators and changes in their Populations were studied in a coastal nursery ground,where flatfish juveniles are concentrated as well as on the entire shelf. Previous studies analysing changes in sea surface temperature for the continental shelf indicate that winter warming occurred in the 1980s and 1990s. Sixteen autumn cruises conducted since 1981 in the Bay of Vilaine nursery area and I I autumn cruises since 1987 over the entire shelf provided data on a nearly annual basis for the abundance of benthic fish. The four most common flatfish species were selected and their occurrence and yearly abundance were analysed with regard to specific biogeographic ranges and climate change. Similar results were obtained for juveniles on a nursery scale and for all age groups on the entire shelf. Although sole (Solea solea) showed irregular yearly variations, northern winter spawners such as plaice (Pleuronectes platessa) and dab (Limanda limanda) exhibited significantly high abundance during the 1980s, followed by a continuing low level and ultimately zero catches. On the other hand, the wedge sole (Dicologoglossa cuneata), a southern summer spawner, showed an increasing trend in the late 1990s.

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Spatial variation in anthropic and natural factors regulating the breeding success of the cinereous vulture (Aegypius monachus) in the SW Iberian Peninsula

Moran-lopez, R Sanchez, JM Costillo, E Corbacho, C Villegas, A


The management of the cinereous vulture (Aegypius monachus) populations, the largest bird of the Western Palaearctic and considered an umbrella species, requires the understanding of the factors limiting the breeding success. As part of a management program, we studied such factors in seven breeding colonies in Extremadura (SW Iberian Peninsula). Using a Geographic Information System and multivariate models, we analyzed the relationship of breeding success with anthropic and natural factors at the nest site and in the foraging area of the adults. We incorporated into the models density-dependent effects between pairs and the spatial autocorrelation of the environmental variables. The differences in breeding success resulted from spatial variations in natural and anthropic conditions, with present human disturbance to nests and future alteration of climate having an expected negative effect at all the sites. Management measures must set calendar restrictions for the immediate environment of the nests, mainly with respect to forestry and hunting activities. A second key element is the protection of the habitats at the nest sites and in their surrounding area, with the aim of there being both wooded areas available for the location of the nest and open environments for the availability of food. The Special Protection Areas showed a partial effectiveness of conservation measures for the species, and the need for future improvement. Lastly, in a scenario of global warming, management policies with respect to nesting habitats will have to be extended to higher altitude zones, actions that should be guided by the study of the selection of potential nesting habitat. (c) 2005 Elsevier Ltd. All rights reserved.

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Screening for high-temperature tolerant cotton cultivars by testing in vitro pollen germination, pollen tube growth and boll retention

Liu, Z Yuan, YL Liu, SQ Yu, XN Rao, LQ


With radical global climate change and global warming, high temperature stress has become one of major factors exerting a major influence on crop production. In the cotton (Gossypium hirsutum L.)-growing areas of China, especially in the Yangtze River valley, unexpected periodic episodes of extreme heat stress usually occur in July and August, the peak time of cotton flowering and boll loading, resulting in lower boll set and lint yield. Breeding programs for screening high temperature-tolerant cotton germplasm and cultivars are urgent in order to stabilize yield in the current and future warmer weather conditions. In the present study, 14 cotton cultivars were quantified for in vitro pollen germination and pollen tube growth in response to temperatures ranging from 10 to 50 degrees C at 5 degrees C intervals. Different cotton genotypes varied in their in vitro pollen germination and pollen tube length responses to the different temperatures. Maximum pollen germination and pollen tube length ranged from 25.2% to 56.2% and from 414 to 682 mu m, respectively. The average cardinal temperatures (T-min, T-opt, and T-max) also varied among the 14 cultivars and were 11.8, 27.3, and 42.7 degrees C for pollen germination and 11.8, 27.8, and 44.1 degrees C for maximum pollen tube length. Variations in boll retention and boll numbers per plant in field experiments were found for the 14 cotton cultivars and the boll retention and boll retained per plant on 20 August varied considerably in different years according to weather conditions. Boll retention on 20 August was highly correlated with maximum pollen germination (R-2= 0.84) and pollen tube length (R-2=0.64). A screening method based on principle component analysis of the combination of pollen characteristics in an in vitro experiment and boll retention testing in the field environment was used in the present study and, as a result, the 14 cotton cultivars could be classified as tolerant, moderately tolerant, moderately susceptible and susceptible to high temperature.

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Dynamical controls on estuarine bathymetry: Assessment against UK database

Prandle, D


New theories for estuarine bathymetry provide formulations for: (1) depth at the mouth, D versus river flow, Q; (2) tidal intrusion length L versus D and Z (tidal amplitude) and (3) a zone of morphological existence, delineated on a framework of Z versus D. Here, these theories are assessed against a database for 80 UK estuaries. Overall there is good agreement between theory and observations for the sizes and shapes of estuaries classified as either ‘Coastal Plain’ or ‘Bar Built’. Likewise, most estuaries are shown to lie within the theoretical ‘zone of bathymetric existence’. These encouraging agreements enable the theories to be used to: (1) enhance our understanding of existing morphologies, (2) identify anomalous estuaries and (3) make future predictions regarding likely impacts from global climate change and related management scenarios. Subsequent examination of regional historical patterns of morphological evolution, introducing detailed local knowledge, should help to explain these anomalies and refine the new theories. By 2100, we anticipate changes in UK estuaries due to (‘precautionary’) projected 25 % changes in river flow of: Order (0.5 -5 km) in lengths and Order (50-250 m) in breadths. Corresponding changes due to a projected sea level rise of 50 cm are increases in both lengths of Order (1-2.5 km) and breadths of Order (70-100 m). In both cases, the bigger changes will occur in larger estuaries. (c) 2006 Elsevier Ltd. All rights reserved.

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Effects of warming conditions in eastern North American forests on red-backed salamander morphology

Gibbs, JP Karraker, NE


Several studies have reported climate-associated changes in phenotypicalty plastic traits of amphibians, yet it remains unknown whether amphibians can manifest an evolutionary response to global climate change at the rate and magnitude that it is occurring. To assess this issue, we examined temporal change in the morphology of the red-backed salamander (Plethodon cinereus), a small, abundant woodland salamander distributed widely in eastern North America with two distinct morphotypes: striped individuals associated with cooler microclimates and unstriped individuals associated with warmer microclimates. We compiled morph, frequencies for 50,960 individual salamanders from 558 sites as recorded in the published literature and in unpublished field notes of herpetologists between 1908 and 2004. We observed that striping probability increased with increasing latitude, longitude, and elevation and decreased (from 80% to 74% range wide) with time. The combined forces of regional climate warming and, particularly, forest disturbance have evidently been sufficient to cause morphological evolution in this amphibian over the last century.

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