Abstracts on Global Climate Change

Dec 2004

Geographical potential of Argentine ants (Linepithema humile Mayr) in the face of global climate change

Roura-Pascual, N Suarez, AV Gomez, C Pons, P Touyama, Y Wild, AL Peterson, AT


Determining the spread and potential geographical distribution of invasive species is integral to making invasion biology a predictive science. We assembled a dataset of over 1000 occurrences of the Argentine ant (Linepithema humile), one of the world’s worst invasive alien species. Native to central South America, Argentine ants are now found in many Mediterranean and subtropical climates around the world. We used this dataset to assess the species’ potential geographical and ecological distribution, and to examine changes in its distributional potential associated with global climate change, using techniques for ecological niche modelling. Models developed were highly predictive of the species’ overall range, including both the native distributional area and invaded areas worldwide. Despite its already widespread occurrence, L. humile has potential for further spread, with tropical coastal Africa and southeast Asia apparently vulnerable to invasion. Projecting ecological niche models onto four general circulation model scenarios of future (2050s) climates provided scenarios of the species’ potential for distributional expansion with warming climates: generally, the species was predicted to retract its range in tropical regions, but to expand at higher latitude areas.

johncross:endorseimp | /endorse/endorseimp | 425

Initial public perceptions of deep geological and oceanic disposal of carbon dioxide

Palmgren, CR Morgan, MG De Bruin, WB Keith, DW


Two studies were conducted to gauge likely public perceptions of proposals to avoid releasing carbon dioxide from power plants to the atmosphere by injecting it into deep geological formations or the deep ocean. Following a modified version of the mental model interview method, Study 1 involved face-to-face interviews with 18 nontechnical respondents. Respondents shared their beliefs after receiving basic information about the technologies and again after getting specific details. Many interviewees wanted to frame the issue in the broader context of alternative strategies for carbon management, but public understanding of mitigation strategies is limited. The second study, administered to a sample of 126 individuals, involved a closed-form survey that measured the prevalence of general beliefs revealed in study 1 and also assessed the respondent’s views of these technologies. Study results suggest that the public may develop misgivings about deep injection of carbon dioxide because it can be seen as temporizing and perhaps creating future problems. Ocean injection was seen as more problematic than geological injection. An approach to public communication and regulation that is open and respectful of public concerns is likely to be a prerequisite to the successful adoption of this technology.

johncross:endorseex | /endorse/endorseex | 437

RNA/DNA ratios as indicators of metabolic activity in four species of Caribbean reef-building corals

Buckley, BA Szmant, AM


Global climate change and the anthropogenic degradation of tropical reef environments can have deleterious consequences for the health of reef-building corals. Bioindicators of coral status aid in efforts to identify those species and populations that are most threatened, which can help focus conservation efforts. The RNA/DNA ratio is an index of protein synthetic capacity and is expected to reflect an organism’s investment in growth. Here, we measured a decrease in the RNA/DNA ratio in both the symbiotic anemone Aiptasia pallida exposed to light-deprivation in the laboratory, and in natural populations of the coral Porites astreoides along a depth gradient, suggesting that the RNA/DNA ratio may have depended upon metabolic activity. Also, RNA/DNA ratios in the coral Montastraea annularis were higher in the winter and spring (when higher growth rates may have been supported) than in summer, at an inshore and an offshore reef in the Florida Keys. Site-specific disparity in bleaching patterns at these 2 reefs may partly explain the differences in their RNA/DNA ratios. Finally, significant interspecific variation was observed in 3 co-occurring species of the genus Montastraea: M. annularis, M. cavernosa and M, faveolata, demonstrating the potential for variability in protein synthetic capacity even between closely related species. These results support the use of the RNA/DNA ratio as an indicator of metabolic activity in natural populations of corals.

johncross:endorseimp | /endorse/endorseimp | 434

The influence of the global climate change on the forest ecosystems in the low tatras Mts

Balaz, P Mindas, J


The paper presents the results of possible regional effects of global climate change on the tree species composition of mountain forest ecosystems. Our model area has been represented by the valleys: Vajskova and Lomnista in Low Tatras Mts region. The suitability of the current and future changed climatic conditions for particular species has been assessed by means of the analysis of the bioclimatic area of each examined tree species. The analysis has been done for the tree species as follows: Norway spruce (Picea abies), silver fir (Abies alba), European beech (Fagus sylvatica), mountain pine (Pinus mugo), sycamore maple (Acer pseudoplatanus), European ash (Fraxinus excelsior), European larch (Larix decidua), mountain ash (Sorbus aucuparia) and cembra pine (Pinus cembra). The results hint at the possibility of considerable changes in the tree composition of mountain forests in the future. The climatic changes will probably have a negative impact primarily on silver fir, Norway spruce and mountain pine - important commercial and stand building species, The effects of the climatic changes are also expected on other species.

johncross:endorseimp | /endorse/endorseimp | 415

Are climate change impacts already affecting tropical forest biomass?

Fearnside, PM


Tropical forests contain large stocks of carbon and any change in the balance of inflows and outflows of carbon to the biomass of standing forest has potentially important consequences for the global carbon cycle and related greenhouse warming, as well as for tropical biodiversity. Despite unresolved controversies over observed changes in biomass and gas fluxes, current observations indicate the likelihood that additional climate change would have substantial impacts on tropical forests and would reinforce their contributions to global climate change. Climate change impacts are already affecting tropical forest biomass. (C) 2004 Elsevier Ltd. All rights reserved.

johncross:endorseimp | /endorse/endorseimp | 414

Impact analysis of climate change for an Alpine catchment using high resolution dynamic downscaling of ECHAM4 time slices

Kunstmann, H Schneider, K Forkel, R Knoche, R


Global climate change affects spatial and temporal patterns of precipitation and so has a major impact on surface and subsurface water balances. While global climate models are designed to describe climate change on global or continental scales, their resolution is too coarse for them to he suitable for describing regional climate change. Therefore, regional climate models are applied to downscale the coarse meteorological fields to a much higher spatial resolution to take account of regional climate phenomena. The changes of atmospheric state due to regional climate change must be translated into surface and sub-surface water fluxes so that the impact on water balances in specific catchments can be investigated. This can be achieved by the coupled regional climatic/hydrological simulations presented here. The non-hydrostatic regional climate model MCCM was used for dynamic downscaling for two time slices of a global climate model Simulation with the GCM ECHAM4 (IPCC scenario IS92a, ‘business as usual) from 2.8 degrees x 2.8 degrees to 4 x 4 km(2) resolution for the years 1991-1999 and 203 1-2039. This allowed derivation of detailed maps showing changes in precipitation and temperature in a region of southern Germany and the central Alps. The performance of the downscaled ECHAM4 to reproduce the seasonality of precipitation in central Europe for the recent climate was investigated by comparison with dynamically downscaled ECMWF reanalyses in 20 x 20 km2 resolution. The downscaled ECHAM4 Fields underestimate precipitation significantly in summer. The ratio of mean monthly downscaled ECHAM4 and ECMWF, precipitation showed little variation. so it was used to adjust the course of precipitation for the ECHAM4/MCCM fields before it was applied in the hydrological model. The high resolution meteorological fields were aggregated to 8-hour time steps and applied to the distributed hydrological model WaSiM to simulate the water balance of the alpine catchment of the river Ammer (c. 700 km(2)) at 100 x 100 m(2) resolution. To check the reliability of the Coupled regional climatic/hydrological simulation results for the recent climate, they were compared with those of a station-based hydrological simulation for the period 1991-1999. This study shows the changes in the temperature and precipitation distributions in the catchment from the recent climate to the future climate scenario and how these will affect the frequency distribution of runoff.

johncross:endorseimp | /endorse/endorseimp | 368

Solving the climate problem - Technologies available to curb CO2 emissions

Socolow, R Hotinski, R Greenblatt, JB Pacala, S

ENVIRONMENT 46:10 8-19

In an effort to avoid serious ecological disruption and global climate change,low-carbon energy strategies need to be implemented on a world-wide scale along with the introduction of carbon policies and carbon management.

johncross:endorseex | /endorse/endorseex | 420