Abstracts on Global Climate Change

Oct 2004

Climate change and the distribution of climatic resources for tourism in North America

Scott, D McBoyle, G Schwartzentruber, M


Tourism is a major sector of the global economy, and it is strongly influenced by climate. At some travel destinations, climate represents the natural resource on which the tourism industry is predicated. Global climate change has the potential to alter the distribution of climate assets among tourism destinations, with implications for tourism seasonality, demand and travel patterns. Changes in the length and quality of the tourism season have considerable implications for the long-term profitability of tourism enterprises and competitive relationships between destinations. This analysis utilizes a ‘tourism climate index’ (TCI) that incorporates 7 climate variables relevant to general tourism activities (i.e. sightseeing) to assess the spatial and temporal distribution of climate resources for tourism in North America under baseline conditions (1961-1990) and 2 climate change scenarios (CGCM2-B2 and HadCM3-A1F1) for the 2050s and 2080s. The analysis found that a substantive redistribution of climate resources for tourism will be possible in the later decades of the 21st century, particularly in the warmer and wetter HadCM3-A1F1 scenario. The number of cities in the USA with ‘excellent’ or’ ideal’ TCI ratings (TCI > 80) in the winter months is likely to increase, so that southern Florida and Arizona could face increasing competition for winter sun holiday travelers and the seasonal ‘snowbird’ market (retirees from Canada and the northern states of the USA, who spend 2 to 6 mo in winter peak and optimal climate destinations). In contrast, lower winter TCI ratings in Mexico suggest it could become less competitive as a winter sun holiday destination. In Canada, a longer and improved warm-weather tourism season may enhance its competitiveness in the international tourism marketplace, with potentially positive implications for its current international tourism account deficit.

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Effect of elevated CO2 concentration and vapour pressure deficit on isoprene emission from leaves of Populus deltoides during drought

Pegoraro, E Rey, A Bobich, EG Barron-Gafford, G Grieve, KA Malhi, Y Murthy, R


To further our understanding of the influence of global climate change on isoprene production we studied the effect of elevated [CO2] and vapour pressure deficit (VPD) on isoprene emission rates from leaves of Populus deltoides Bartr. during drought stress. Trees, grown inside three large bays with atmospheres containing 430, 800, or 1200 mumol mol(-1) CO2 at the Biosphere 2 facility, were subjected to a period of drought during which VPD was manipulated, switching between low VPD ( approximately 1 kPa) and high VPD ( approximately 3 kPa) for several days. When trees were not water-stressed, elevated [CO2] inhibited isoprene emission and stimulated photosynthesis. Isoprene emission was less responsive to drought than photosynthesis. As water-stress increased, the inhibition of isoprene emission disappeared, probably as a result of stomatal closure and the resulting decreases in intercellular [CO2] (C-i). This assumption was supported by increased isoprene emission under high VPD. Drought and high VPD dramatically increased the proportion of assimilated carbon lost as isoprene. When measured at the same [CO2], leaves from trees grown at ambient [CO2] always had higher isoprene emission rates than the leaves of trees grown at elevated [CO2], demonstrating that CO2 inhibition is a long-term effect.

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Vulnerability of waterborne diseases to climate change in Canada: A review

Charron, DF Thomas, MK Waltner-Toews, D Aramini, JJ Edge, T Kent, RA Maarouf, AR Wilson, J


This project addresses two important issues relevant to the health of Canadians: the risk of waterborne illness and the health impacts of global climate change. The Canadian health burden from waterborne illness is unknown, although it presumably accounts for a significant proportion of enteric illness. Recently, large outbreaks with severe consequences produced by E. coli O157:H7 and Cryptosporidium have alarmed Canadians and brought demands for political action. A concurrent need to understand the health impacts of global climate changes and to develop strategies to prevent or prepare for these has also been recognized. There is mounting evidence that weather is often a factor in triggering waterborne disease outbreaks. A recent study of precipitation and waterborne illness in the United States found that more than half the waterborne disease outbreaks in the United States during the last half century followed a period of extreme rainfall. Projections of international global climate change scenarios suggest that, under conditions of global warming most of Canada may expect longer summers, milder winters, increased summer drought, and more extreme precipitation. Excess precipitation, floods, high temperatures, and drought could affect the risk of waterborne illness in Canada. The existing scientific information regarding most weather-related adverse health impacts and on the impacts of global climate change on health in Canada is insufficient for informed decision making. The results of this project address this need through the investigation of the complex systemic interrelationships between disease incidence, weather parameters, and water quality and quantity, and by projecting the potential impact of global climate change on those relationships.

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The potential distribution of zebra mussels in the United States

Drake, JM Bossenbroek, JM

BIOSCIENCE 54:10 931-941

The range expansion of zebra mussels (Dreissena polymorpha) in North America has been rapid and costly in both economic and ecological terms. joint social, political, and scientific ventures such as the 100th Meridian Initiative aim to reduce the spread of zebra mussels by eliminating the unintended transport of the species and preventing its westward expansion. Here we forecast the potential distribution of zebra mussels in the United States by applying a machine-learning algorithm for nonparametric prediction of species distributions (genetic algorithm for rule-set production, or GARP) to data about the current distribution of zebra mussels in the United States and 11 environmental and geological covariates. Our results suggest that much of the American West will be uninhabitable for zebra mussels. Nonetheless, some catchments along the West Coast and in the southeastern United States exhibit considerable risk of invasion and should be monitored carefully. Possible propagule dispersal to these places should be managed proactively.

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Responses of foraminiferal isotopic variations at ODP Site 1143 in the southern South China Sea to orbital forcing

Tian, J Wang, PX Cheng, XR


The foraminiferal delta(18)O and delta(13)C records for the past 5 Ma at ODP Site 1143 reveal the linear responses of the Plio-Pleistocene climatic changes in the southern South China Sea to orbital forcing at the obliquity and precession bands. The phase of the 5180 variations with the orbital forcing is opposite to that of the delta(13)C, which may be caused by the frequent El Nino events from the equatorial Pacific. The amplification of the Northern Hemisphere Ice Sheet at similar to3.3 Ma probably affected the development of the 100-ka climatic cycles. Its further spreading may spur the 100-ka climatic cycle to become the dominant cycle in the late Pleistocene. The “Mid-Pleistocene Transition” event has localized influence on the isotopic variations in the southern South China Sea. The foraminiferal delta(13)C records for the past 5 Ma at Site 1143 are highly coherent with the orbital forcing at the long eccentricity band, and lead the delta(18)O records at the shorter eccentricity band, highlighting the importance of the carbon cycle in the global climate change.

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Can climate data from METEOSAT improve wildlife distribution models?

Suarez-Seoane, S Osborne, PE Rosema, A

ECOGRAPHY 27:5 629-636

Global climate change generated by human activities is likely to affect agroecosystems in several ways: reinforcing intensification in northern and western Europe, and extensification in the Mediterranean countries. If we are to predict the consequences of global warming for wildlife, distribution models have to include climate data. The METEOSAT temporal series from EWBMS offers an attractive alternative to using climatic surfaces derived from ground stations. The aim of this paper is to test whether this climatic satellite data can improve the distribution models obtained previously by Suarez-Seoane et al. using habitat variables for three agro-steppe bird species: great bustard, little bustard and calandra lark in Spain. Rainfall, radiation balance, evapotranspiration and soil moisture images were incorporated together with the other variables used as predictors in the published stepwise GAM models. Changes in the predicted distributions from the habitat only and climate-habitats models were assessed by reference to the CORINE land cover categories. Inclusion of climatic variables from METEOSAT led to statistically superior models for all three species. There were large differences in the climatic variables selected and the original variables dropped among the species. Evapotranspiration variables were the most frequently selected. Maps of the differences between the habitat and climate-habitat models showed very different patterns for the three species. Inclusion of climate variables led to a wider range of land cover types being deemed suitable. Despite the statistical superiority of models, care is needed in deciding whether to use climatic variables because they may emphasize the fundamental rather than the realized niche. Used together, however, habitat and climate models can provide new insights into factors limiting species distributions and how they may respond to climate change.

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Age-related environmental sensitivity and weather mediated nestling mortality in white storks Ciconia ciconia

Jovani, R Tella, JL

ECOGRAPHY 27:5 611-618

We studied environmental sensitivity and mortality related to weather inclemency in white stork nestlings Ciconia ciconia in their southern European boundary (Donana, SW Spain). The study of homeothermy acquisition and fault bars (i.e. a measure of stress on feathers) revealed that stork nestlings were specially sensitive to environmental conditions occurring before 20 d of age. Accordingly, most of nestling mortality concentrated during this sensitive period: 91% of deaths corresponded to nestlings younger than 20 d, 73% concentrating on nestlings up to 10 d-old. Nestling mortality and total breeding failure were highly variable among years, being especially high when rainy periods coincided with the early live of nestlings (between 1 April and 15 May). Maximum temperatures had a positive correlation with breeding success and nestling survival but this effect disappeared when controlling for rainfall. Our results are in agreement with previous studies conducted in other white stork populations in other latitudes. We suggest that this could be the result of a low homeothermy capacity of young nestlings jointly with an early breeding phenology that expose white storks to rain, but not to high temperatures. In the context of global climate change we suggest that the current decrease on spring rainfall could increase nestling survival while punctual rainy springs could have a negative effect on the reproduction of white storks.

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PARAGON - An integrated approach for characterizing aerosol climate impacts and environmental interactions

Diner, DJ Ackerman, TP Anderson, TL Bosenberg, J Braverman, AJ Charlson, RJ Collins, WD Davies, R Holben, BN Hostetler, CA Kahn, RA Martonchik, JV Menzies, RT Miller, MA Ogren, JA Penner, JE Rasch, PJ Schwartz, SE Seinfeld, JH Stephens, GL Torres, O Travis, LD Wielicki, BA Yu, B


Aerosols exert myriad influences on the earth’s environment and climate, and on human health. The complexity of aerosol-related processes requires that information gathered to improve our understanding of climate change must originate from multiple sources, and that effective strategies for data integration need to be established. While a vast array of observed and modeled data are becoming available, the aerosol research community currently lacks the necessary tools and infrastructure to reap maximum scientific benefit from these data. Spatial and temporal sampling differences among a diverse set of sensors, nonuniform data qualities, aerosol mesoscale variabilities, and difficulties in separating cloud effects are some of the challenges that need to be addressed. Maximizing the long-term benefit from these data also requires maintaining consistently well-understood accuracies as measurement approaches evolve and improve. Achieving a comprehensive understanding of how aerosol physical, chemical, and radiative processes impact the earth system can be achieved only through a multidisciplinary, inter-agency, and international initiative capable of dealing with these issues. A systematic approach, capitalizing on modern measurement and modeling techniques, geospatial statistics methodologies, and high-performance information technologies, can provide the necessary machinery to support this objective. We outline a framework for integrating and interpreting observations and models, and establishing an accurate, consistent, and cohesive long-term record, following a strategy whereby information and tools of progressively greater sophistication are incorporated as problems of increasing complexity are tackled. This concept is named the Progressive Aerosol Retrieval and Assimilation Global Observing Network (PARAGON). To encompass the breadth of the effort required, we present a set of recommendations dealing with data interoperability; measurement and model integration; multisensor synergy; data summarization and mining; model evaluation; calibration and validation; augmentation of surface and in situ measurements; advances in passive and active remote sensing; and design of satellite missions. Without an initiative of this nature, the scientific and policy communities will continue to struggle with understanding the quantitative impact of complex aerosol processes on regional and global climate change and air quality.

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Nitrogen input mediates the effect of free-air CO2 enrichment on mycorrhizal fungal abundance

Staddon, PL Jakobsen, I Blum, H


Plots containing Lolium perenne L., Trifolium repens L. or a mixture of both plant species were exposed to elevated atmospheric CO2 (eCO(2)) for 10 consecutive seasons using free-air CO2 enrichment technology at ETH Zurich, Switzerland. The CO2 treatment was crossed with a two-level nitrogen (N) fertilization treatment. In the tenth year, soil samples were collected on three occasions through the growing season to assess the impact of eCO(2) and N fertilization on mycorrhizal fungal abundance. Soil moisture content, which varied with harvest date, was linked to the vegetation type and was higher under eCO(2). Root weight density was affected by vegetation type: lower for clover, higher for grass. Root weight density was stimulated by eCO(2) and decreased by high N fertilization. The percent root length colonized by mycorrhizal fungi was lowest in the clover plots and highest in the grass plots. High N significantly decreased root length colonized. There was no overall effect of eCO(2) on root length colonized; however, there was a significant eCO(2)x N interaction: eCO(2) increased root length colonized at high N, but decreased root length colonized at low N. Extraradical mycorrhizal hyphal density was linked to soil moisture content. Extraradical mycorrhizal hyphal density was not affected by eCO(2) or high N individually, but as for root length colonized, there was a significant eCO(2)x N interaction: eCO(2) increased extraradical mycorrhizal hyphal density at low N but not at high N. These environmental effects on root colonization and external mycorrhizal hyphae were independent of soil moisture content and root weight density. This field study demonstrated a significant mediating effect of N fertilization on the response of arbuscular mycorrhizal fungi to eCO(2) irrespective of any change in root biomass.

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Risk and climate change: Perceptions of key policy actors in Canada

Stedman, RC

RISK ANALYSIS 24:5 1395-1406

This article examines factors that predict perceptions of risk associated with global climate change. The research focuses on the perceptions of those associated with climate change policy making in the prairie region of Canada. The data are from an online survey (n = 851) of those policy actors. The analysis integrates several dominant approaches to the study of risk perception: psychometric approaches that examine the effects of cognitive structure; demographic assessments that examine, for example, differences in perception based on gender or family status; and political approaches that suggest that one’s position in the policy process may affect his or her perceived risk. Attitudes toward climate change are to a degree predicted by all of these factors, but only when indirect effects are observed. Sociodemographic characteristics have little direct effect on perceived risk, but do affect general beliefs that affect risk perceptions. Perceived risk is related more strongly to these general beliefs or world views than to more specific beliefs about the effects of climate change on weather patterns. Position within the policy process also contributes to our understanding of perceptions, with industry and governmental actors demonstrating similar attitudes, which contrast with environmental groups and university researchers.

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Divergent pheromone-mediated insect behaviour under global atmospheric change

Mondor, EB Tremblay, MN Awmack, CS Lindroth, RL


While the effects of global atmospheric changes on vegetation and resulting insect populations(‘bottom-up interactions’) are being increasingly studied, how these gases modify interactions among insects and their natural enemies (‘top-down interactions’) is less clear. As natural enemy efficacy is governed largely by behavioural mechanisms, altered prey finding and prey defence may change insect population dynamics. Here we show that pheromone-mediated escape behaviours, and hence the vulnerability of insects to natural enemies, are divergent under atmospheric conditions associated with global climate change. Chaitophorus stevensis, a common aphid on trembling aspen trees, Populus tremuloides, have diminished escape responses in enriched carbon dioxide (CO2) environments, while those in enriched ozone (O-3) have augmented escape responses, to alarm pheromone. These results suggest that divergent pheromone-mediated behaviours could alter predator-prey interactions in future environments.

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