GC11B-01
Fossil Find on Svalbard Highlights the Natural History of the Polar Bear (Ursus maritimus)
During recent fieldwork on Svalbard a well preserved subfossil left ramus of a polar bear (Ursus maritimus) mandible was discovered. A 14C age determination shows that it is older than 45 ka (kilo-years), and an OSL (Optical Stimulated Luminescence) age determination together with the stratigraphic position of the bone suggests that it is of Eemian-Early Weichselian/Wisconsinan age, 150-80 ka old. This puts the find among the oldest fossil remains of a polar bear ever discovered. Osteological study of the mandible suggests that it comes from a fully grown female. The fossil record suggests that polar bears may have developed from brown bears during the early part of the last glacial cycle, some 100 ka ago. The present interglacial might be the first such that the species has to endure. This underlines the potential status of the polar bears as an endangered species if the current warming trend and diminishing of sea ice cover in the Arctic continues.
GC11B-02
CH4 AND CO2 FLUXES FROM THE ARCTIC TUNDRA DURING THE BIOCOMPLEXITY MANIPULATION EXPERIMENT
Previous research involving long-term, replicated chamber studies have demonstrated strong linkages between the tundra carbon cycle and thermal and soil hydrologic processes at local (centimeter to meter) scales and individual land cover units. Soil water content is particularly important in that it can potentially affect all of these variables. Alteration of local hydrology will, therefore, have a profound and complex effect on soil respiration, methanogenesis and the associated rates of decomposition and mineralization and consequently on carbon fluxes. Methane is an effective greenhouse gas that has a warming potential about 23 times that of CO2. The wetland regions of the world (especially the ones located in the boreal and low Arctic) were major accumulation sites of organic materials under anaerobic conditions and could be a significant source of global CH4 and CO2. Wet sedge ecosystems appeared to be the dominant Arctic and subarctic sources of methane. It is important to note, however, that the large majority of these measurements were performed with the use of flux chambers. While chambers have the advantage of effectively characterizing different vegetation and micro-topographic sites, they have the disadvantage of being discrete (non-continuous) measurements in time and space. In addition to this the installation of chambers in the soils disrupts the integrity of the surface and could significantly impact the gas fluxes. This research presents the results of a three years large scale manipulation performed to investigate the response of the arctic tundra carbon balance to wetting and drying at various levels of biological organization (microbial to landscape ecology) and over multiple spatial and temporal scales over an area of approximately 50 hectares of coastal tundra. The manipulation experiment was conducted in the BEO (Biological Experimental Observatory), in Barrow, Alaska, in a drained lake basin that was dived in three parts by the placement of dikes separating three areas in which water was pumped to create three different water table heights. During the baseline years (2005 and 2006) before the placement of the dikes the three areas showed similar fluxes and the ecosystem was a source of CH4 of around 2 mg m-2 hr-1. The use of micrometeorological instead of chamber measurements allowed investigating the effects of flooding and drying on CH4 fluxes over large areas without disturbances on soil and vegetation. Our results indicate that the process of methane release is more complicated than expected and that sites with considerably different water table depths were very similar sources of CH4 fluxes of about 2 mg m-2 hr-1. Within the natural ranges observed, and the manipulations performed, areas with different water table depths were characterized by very similar fluxes. This raises the possibility that the response of net methane emission is more complicated than previously thought and raises uncertainties concerning the estimation of the methane release in response to drying or wetting of the Arctic and makes less clear the actual impact of Climate Change on methane and carbon dioxide fluxes of the Arctic tundra.
GC11B-03
Monitoring Polar Environmental Change Using FORMOSAT-2 Satellite
Polar ice loss to the sea currently account for virtually all of the sea-level rise that is not attributable to ocean warming. Huge section of the Ayles Ice Shelf broke off into the Arctic Ocean. Permafrost soil is losing its permanence across the Northern Hemisphere, altering ecosystems and damaging roads and buildings across Alaska, Canada, and Russia. Global warming change the polar environment significantly, especially in recent year. The National Space Organization (NSPO) of Taiwan successfully launched FORMOSAT-2 on 20 May 2004. The orbit is designed to be high-altitude,. Sun-synchronous, and daily-revisit. With high agility in attitude control, FORMOSAT-2 can cover the polar areas up to +/- 90 deg latitude. More than 72 Area of interests in Alaska, Canada, Greenland area and Ice land have imaged periodically in 2006 and 2007. The images have 2m resolution in panchromatic band and 8m in multispectral bands, with size of about 24 x 100 km or large. The ability of FORMOSAT-2 daily revisit has been extended to monitor the change of topography for the glacier and ice shelf daily, weekly and monthly. By using the FORMOSAT-2 stereo pair, we can determine the elevation profile (DEM) across the glacier surface. In this paper, we will present the mapping and topography of Greenland glaciers and ice land including Kangerdlugssuaq Glacier, Greenland, Belcher Glacier, Canada and Ayles ice island. We will demonstrate the DEM extract ability from FORMOSAT-2 polar stereo images( up to 82 deg latitude), and compared with the DEM of the popular SRTM, ASTER which can be acquired to 79 deg latitude. It is expected that FORMOSAT-2 polar images will be continuously collected for years and contribute to the research of global environmental change.
GC11B-04
Climate change in Canadian forests: Effect of global warming and CO2 fertilization on natural populations of black and white spruce
Global increases in temperature and atmospheric CO2 concentration are predicted to enhance tree growth in the short term, but studies of current impacts of climate change on Canada's forests are limited. This study examined the effects of increasing temperature and atmospheric CO2 concentration on tree ring growth in west-central Manitoba and northern Ontario, sampling white spruce (Picea glauca) and black spruce (Picea mariana), respectively. Over 50 tree cores from each site were sampled, analysed for ring-width, cross-dated and detrended, generating a ~100 y chronology for each population. We found a positive correlation between ring-width increment and spring temperatures (April-May: p<0.005) in Ontario. In Manitoba, however, we found a negative correlation between summer temperatures (Jul-Aug: p<0.005) and ring-width increment coincident with a positive relationship with summer precipitation (July: p<0.03). We examined the residuals following a regression with temperature for a positive trend over time, which has been interpreted in prior studies as evidence for a CO2 fertilization effect. We detected no such putative CO2 fertilization signal in either spruce population. Our results suggest that temperature-limited lowland black spruce communities may respond positively to moderate warming, but that water-limited upland white spruce communities may suffer from drought stress under high temperature conditions. Neither population appears to benefit from increasing CO2 availability.
GC11B-05
A UAV System for Observing Volcanoes and Natural Hazards
Fixed or rotary wing manned aircraft are currently the most commonly used platforms for airborne reconnaissance in response to natural hazards, such as volcanic eruptions, oil spills, wild fires, earthquakes. Such flights are very often undertaken in hazardous flying conditions (e.g., turbulence, downdrafts, reduced visibility, close proximity to dangerous terrain) and can be expensive. To mitigate these two fundamental issues-- safety and cost--we are exploring the use of small (less than 100kg), relatively inexpensive, but effective, unmanned aerial vehicles (UAVs) for this purpose. As an operational test, in 2004 we flew a small autonomous UAV in the airspace above and around Stromboli Volcano. Based in part on this experience, we are adapting the RAVEN UAV system for such natural hazard surveillance missions. RAVEN has a 50km range, with a 3.5m wingspan, main fuselage length of 4.60m, and maximum weight of 56kg. It has autonomous flight capability and a ground control Station for the mission planning and control. It will carry a variety of imaging devices, including a visible camera, and an IR camera. It will also carry an experimental Fourier micro-interferometer based on MOEMS technology, (developed by IMM Institute of CNR), to detect atmospheric trace gases. Such flexible, capable, and easy-to-deploy UAV systems may significantly shorten the time necessary to characterize the nature and scale of the natural hazard threats if used from the outset of, and systematically during, natural hazard events. When appropriately utilized, such UAVs can provide a powerful new hazard mitigation and documentation tool for civil protection hazard responders. This research was carried out under the auspices of the Italian government, and, in part, under contract to NASA at the Jet Propulsion Laboratory.
GC11B-06 INVITED
Climate Change Impacts on the Electric Power System in the Western United States
Future climate change is projected to vary substantially across regions. Changes in regional temperature and precipitation patterns may have significant implications on our existing and future power system infrastructure. In this paper, we use results from regional climate models to examine the impacts of projected changes in temperature and precipitation on the development and operations of the power system in the Western United States. We study three scenarios to evaluate potential effects of climate change on the electricity demand as well as on the power supply side. Impacts are measured in terms of changes in investment requirements, fuel and generation mix, emissions of greenhouse gases and criteria pollutants, and thermal power water withdrawals and consumption. We also identify potential issues regarding the western transmission grid. Our methodology includes a long-term investment algorithm that takes into account interdependencies between hydroelectric, thermal power, and non-dispatchable resources, such as wind turbines. We also include temporal aspects associated with hydropower energy constraints, wind variability, thermal power plant availability, and hourly load profiles. Thermal power plant availability and resulting generation and fuel consumption are based on maintenance outage schedules and a probabilistic dispatch algorithm that accounts for random forced outages. We conclude with some observations regarding the vulnerability of our electricity infrastructure to projected regional climate changes.
GC11B-07
Setting Goals for Urban Scale Climate Governance
The impacts of climate change on temperate urban areas may include the increase in frequency and intensity of damaging extreme weather events, such as heat waves, hurricanes, heavy rainfall or drought, and coastal flooding and erosion, and potential adverse impacts on infrastructure, energy systems, and public health. Warmer average summertime temperatures are also associated with environmental and public health liabilities, such as decreased air quality and increased peak electrical demand. Simultaneously, a strong global trend towards urbanization of poverty exists, with increased challenges for local governments to protect and sustain the well-being of growing cities and populations currently stressed by poverty, health and economic inequities. In the context of these trends, research at the city scale has sought to understand the social and economic impacts of climate change and variability and to evaluate strategies in the built environment that might serve as adaptive and mitigative responses to climate change. We review the goals and outcomes of several municipal climate protection programs, generally categorized as approaches based on technological innovation (e.g., new materials); changes in behavior and public education (e.g., neighborhood watch programs and cooling centers); improvements in urban design (e.g., zoning for mixed land-use; the use of water, vegetation and plazas to reduce the urban heat island effect); and efforts to incentivize the use of non-fossil-fuel based energy sources. Urban initiatives in European and American cities are assessed within the context of the global collective efforts enacted by the Kyoto Protocol and United Nations Framework Convention on Climate Change. Our concern is to understand the active networked role of urban managers in climate policies and programs in relation to supranational objectives and non-state actors.
GC11B-08
Adaptation Strategies for Global Environmental Change
The global environmental challenges society faces today are unheralded due to the pace at which human activities are affecting the earth system. The rates of energy consumption, nitrogen use and production, and water use increases each year leading to greater global environmental changes affecting warming of the earth system and loss of ecosystem services. The challenge we face today as a society is the manner and speed at which we can adapt to these changes affecting the ecosystem services we depend upon. Innovative strategies are needed to develop the adaptive management tools to integrate the sectors and science necessary to deal with the complexity of effects. Developing strategies to better guide decision making related to climate change trends into changing weather patterns at meaningful temporal and spatial scales are needed, observations and prognostic analyses of climate related triggers of threshold events in ecosystem dynamics, and transfer of knowledge between science, technology, and decision makers. These strategies need to better integrate science (physical, biological, and social knowledge), engineering, policy, and economics interests to create a framework to develop strategies for adaptation and mitigation to global change and to create bridges with institutions and organizations that deal with these issues as a governmental agency or private sector enterprise.