Global Climate Change II Posters
Presiding: S Burr, Cornell University; R Davis, California Institute of Technology
GC41A-01 0830h
Followed and Surveillance of the Desertification Phenomenon with Remote Sensing Data ~ ALSAT-1 ~ in Semi-Arid Zones (steppe of Algeria)
The degradation of the natural resources in the arid and semi arid land has drastically been emphasized during this century because of the demographic growth and the transformation of the land use systems. The extension of the cultivated areas in the marginal land and the cattle growth led to different processes of degradation, green cover destruction, over pasture land erosion and their fertility deterioration. The steppe in Algeria is presented in the form of pathways of Alfa and for the majority; these pathways are degraded with low recovery. This, under the aridity affect of the medium and the over pasture which is being forced on this pathways makes the degradation process worse for the physical medium and then lead to desertification. All the time, the politicians have been searching with more or less success to master the natural resources and to diminish the aggressive effects exerted by man in a conscience or no conscience manner on the medium. With all these problems to which the Algerian steppe allowing the determination of the lands, being damaged by desertification. And also to better use the pastoral resources. The work is mainly based on the classification criteria of the arid lands and the steppe, these criteria are numerous, climatic, phytogeographic, pedology and agronomic. The approach is based on the Land sat data of ALSAT-1 images completed with terrain observation. With regard to the ecosystem fragility a synthesis chart was designed. Keywords: semi arid land, degradation, steppe and pathways, over pasture, desertification, and pastoral resources.
GC41A-02 0830h
A Comparison of Anthropogenic Carbon Dioxide Emissions Datasets: UND and CDIAC
Using data from the Department of Energy's Energy Information Administration (EIA), a technique is developed to estimate the monthly consumption of solid, liquid and gaseous fossil fuels for each state in the union. This technique employs monthly sales data to estimate the relative monthly proportions of the total annual carbon dioxide emissions from fossil-fuel use for all states in the union. The University of North Dakota (UND) results are compared to those published by Carbon Dioxide Information Analysis Center (CDIAC) at the Oak Ridge National Laboratory (ORNL). Recently, annual emissions per U.S. state (Blasing, Broniak, Marland, 2004a) as well as monthly CO2 emissions for the United States (Blasing, Broniak, Marland, 2004b) have been added to the CDIAC website. To determine the success of this technique, the individual state results are compared to the annual state totals calculated by CDIAC. In addition, the monthly country totals are compared with those produced by CDIAC. In general, the UND technique produces estimates that are consistent with those available on the CDIAC Trends website. Comparing the results from these two methods permits an improved understanding of the strengths and shortcomings of both estimation techniques. The primary advantages of the UND approach are its ease of implementation, the improved spatial and temporal resolution it can produce, and its universal applicability.
GC41A-03 0830h
Carbon Dioxide Emissions From Fossil-Fuel Consumption in Indonesia
Applying monthly sales and consumption data of coal, petroleum and natural gas, a monthly time series of carbon dioxide emissions from fossil-fuel consumption is created for Indonesia. These are then modeled with an autoregressive function to produce a quantitative description of the seasonal distribution and long-term pattern of CO2 emissions. Currently, Indonesia holds the 21st ranked position in total anthropogenic CO2 emissions among countries of the world. The demand for energy in Indonesia has been growing rapidly in recent years as Indonesia attempts to modernize and upgrade the standard of living for its citizens. With such a large population (a quarter of a billion people), the recent increase observed in the per capita energy use equates to a large escalation in total CO2 emissions. However, the economy and political climate is rather turbulent and thus emissions tend to fluctuate wildly. For example, Indonesia's energy consumption dropped substantially during the Asian economic crisis in the late 1990s. It is likely that the recent tsunami will also significantly impact energy consumption as the hard-hit Aceh region is the largest fuel-producing region of Indonesia. Therefore, Indonesia is a country whose emissions are more unpredictable than most countries that emit comparable levels of CO2. Complicating matters further, data collection practices in Indonesia are less diligent than in other countries with more stable economies. Thus, though CO2 emissions from Indonesia are a particular challenge to model, they are an important component to understanding the total global carbon cycle.
GC41A-04 0830h
Climate Change Effects on North American Ecosystems: Contribution to the 2007 IPCC Assessment
The MAPSS team has generated model simulations of future climate impacts on ecosystems in the United States for several national and international assessments, including those of the Intergovernmental Panel on Climate Change (IPCC). The IPCC is currently drafting its next assessment using a new suite of future climate scenarios. We have generated new ecosystem simulations using our MC1 dynamic general vegetation model (DGVM) that depict potential changes in vegetation distribution, fire dynamics, and carbon sequestration in response to six of these new climate scenarios. The six climate scenarios were constructed for North America using General Circulation Model (GCM) output from three different models (Canadian CGCM2, UK HadCM3, and Australian CSIRO Mk2) forced by two different emission scenarios (IPCC SRES A2 and B2). By 2100, the climate scenarios show a projected temperature increase of about 6o C in summer and 8oC in winter for the A2 emissions scenario, compared to 4oC and 6oC for B2, respectively. The scenarios also show winter precipitation increasing by as much as 20% under the A2 emissions scenario, and 10% under the B2. We were able to compare the results of our MC1 ecosystem simulations under these new climate scenarios to those under older climate scenarios generated by two of the GCMs (Canadian and UK) in the conterminous United States. Differences in the response of vegetation, fire, and carbon were most pronounced in the Pacific Northwest and southwestern United States where one or more of the newer scenarios were significantly drier.
GC41A-05 0830h
Thermal Offset of Soil and Air Temperatures in the Great Plains of the United States: Implications for Borehole Climate Reconstruction.
Previous studies have shown that the nature of the long-term coupling of air and ground temperatures varies systematically along a latitudinal gradient in the Great Plains of the United States. These variations may have significance with respect to the validity of thermophysical assumptions implicit in borehole climate reconstructions. In this study we investigate the relationship between the thermal offset of long-term soil temperatures measured at 10-cm depth and long-term shelter height air temperatures. The thermal offset (Tsoil - Tair) for the mean annual, mean winter (DJF), and mean summer (JJA) periods is examined for a 45-station network in the central and northern Great Plains of the United States (Kansas, Nebraska, South Dakota, and North Dakota). Data is obtained from the Great Plains Regional Climate Center for ten complete seasonal years running from 1 May 1993 through 30 April 2003. We examine the regional patterns of the thermal offset for the annual, winter, and summer periods based upon the ten years of data, as well as for selected years of high and low regional snowfall totals. We also consider regional variations in snowfall amount (cm) and snow cover (cm) for the same study period. Results show a systematic increase in the annual thermal offset with increasing latitude, ranging from 1° C along the southern study region limit to 4° C along the northern limit. These annual values mask a significant seasonal contrast, however. The winter thermal offset follows a strong latitudinal gradient that ranges from less than 1° C in the southwest of the region to more than 10° C in the northeast, and which is related to regional snowfall and snow cover controls. The summer thermal offset, however, follows a weaker longitudinal gradient that ranges from 0° C in the east to 3° C in the west, and which is related to regional precipitation controls. The regional thermal offset is primarily determined by the thermoinsulation effect of snow cover, along with secondary controls associated with the availability of surface soil moisture, and the release of latent heat of fusion along the advancing freezing front. Interannual variability in the thermal offset due to regional snow cover variations will be examined, and the implications of the study results for borehole climate reconstructions will be discussed.
GC41A-06 0830h
Evaluating the Impacts of Climate variability on Agriculture: an integrated modeling approach
Climate variability is just one factor that affects agriculture, other factors such as socio-economic conditions, demographic changes, land use and land cover changes, and water allocation policies also have significant impacts. In this research, the exposure of Florida agriculture to multiple stresses is analyzed using an integrated modeling approach, based on system dynamics modeling principles. The model consists of five interacting sectors of population, land use, water use, pollution and economy. Land use is further divided into urban/industrial, farmland, commercial forest, and state forest. Water use consists of demand for domestic, industrial, agricultural, environmental, and recreational purposes. The framework of the model is described, and the results of alternate policy runs and a sensitivity analysis are presented. The integrated model is used to explore three policy scenarios. First, we explore if current trends of demographic change, water use and land use continue, what will happen under different climate variability scenarios (i.e., change in temperature and precipitation, both in time and space). Second, we explore scenarios with changes in water demand and supply through adding desalinization plants, reducing water losses, preserving water through efficient use, changing crop variety and pattern, and importing virtual water. Third, we explore scenarios based on land use changes considering land allocation for alternate uses (e.g., changing commercial forest to agricultural use) and changing land use within certain category (e.g., different crops within agricultural land use). The research advances work on estimating the impacts of climate variability on agriculture by considering dynamic interaction among multiple influencing factors. The results should help agencies involved in management of agriculture and water resources in Florida to develop policies for sustainable management of these resources.