Addressing Climate Change Treaties by Modeling Land Use Policies

During late 1997, the United Nations Framework Convention on Climate Change (UNFCCC) met in Kyoto, Japan, to address the issue of global warming. At this meeting participating nations agreed upon specific quantified emission limitations and reduction commitments of greenhouse gas emissions to mitigate possible climate change. The United States agreed to reduce greenhouse gas emissions 7 percent below 1990 emission levels by the period of 2008 to 2012.

With this commitment in mind, a framework was developed using a GIS that allows for the enactment and evaluation of legislative policies intended to mitigate a nation's or state's carbon dioxide (CO2) budget. This research was conducted in the Silicon Graphics workstation laboratory at Bowling Green State University in Ohio. ArcInfo was used for data manipulation and ArcView GIS was used to display the data generated through land use policy modeling. CO2 was chosen as the greenhouse gas for the primary stage of this study because it has contributed far more to the threat of global climate change than any other anthropogenic greenhouse gas. Additionally, CO2 is the only greenhouse gas currently capable of being removed from the atmosphere. The modeling methodologies discussed herein were enacted using data for the State of Ohio; however, the procedural framework produced through this study can be adapted for any nation or state.

The first step in this study was to establish a CO2 inventory that documented quantities of annual emissions and absorptions of CO2 in Ohio. Annual emissions and absorptions of CO2 were calculated using internationally accepted formulae that required the input of specific data acquired from regional and national agencies, organizations, and Businesses. Once the compilation of this inventory was completed, a conceptual model of the relationship between these sources and sinks of CO2 and the entire CO2 budget for the State was developed. The next stage of the project utilized a GIS, where models were created that allowed for the investigation of the relationship between hypothetical land use policies involving forestry and the CO2 budget for Ohio. Forest acreage data generated using these models was plugged into the conceptual model of Ohio's CO2 budget so that the impact they had toward mitigating the budget could be evaluated.

Hypothetical legislative policies enacted using a GIS produced additional forest areas alongside existing forests, railroads, primary roads, and rivers/streams of the State as different reasonably sized buffer zones. These areas were chosen because there would be minimal impact on existing land use, and these areas often remain free of forest despite not being used for any other type of development. The primary data sets consisted of a natural area land cover image of Ohio provided by the Ohio Department of Natural Resources (ODNR)-Division of Wildlife and coverages of the railroads, primary roads, and rivers/streams within the United States published by Esri. The land cover image provided by ODNR, which was assembled from Landsat 5 images, aerial photographs, and United States Geological Survey digital line graph files, was converted into a grid. This grid was then reclassified, smoothed, and converted into polygon format so that its forest data could be manipulated using ArcInfo.

To determine the amount of forest that originally existed within these buffer zones, some intersections were performed with the buffer zones created along the State features and the forest polygon coverage to produce new coverages containing the polygons common only to both input coverages. How much new forest was actually created within the State for a given distance of buffer zone along Ohio's railroads, primary roads, or rivers/streams was then calculated using ArcView GIS. Once the newly created forest acreage figures were determined from each of the hypothetical policy enactments, the CO2 budget conceptual model for Ohio was utilized to calculate and evaluate the impact that the different policies had on Ohio's CO2 budget.

Through the enaction of the forestation policies using a GIS in this study, it was determined that increasing Ohio's forestry is a method capable of significantly contributing to lowering Ohio's CO2 budget. However, increasing forestation through reasonably sized buffer zones alone cannot mitigate Ohio's CO2 budget to the desired goal of 7 percent (similar to that of the United States Kyoto commitment) established at the start of this study. In addition to making realistic increases in its forest acreage, the State of Ohio will also have to take steps to lower its emissions of CO2 through legislation that will most likely target fossil fuel consumption. It is important to note that Ohio ranks as one of the major consumers of fossil fuels per capita in the world, and therefore other nations or states that consume less fossil fuels will likely better mitigate their CO2 budget with similar forestation policies.

To achieve the goal of reducing net greenhouse gas emissions in the most effective way, a nation or state must not only consider the reduction of greenhouse gas emissions, but must also consider other tactics such as the possibility of absorbing more CO2 through different land use strategies. Through this study it has been demonstrated that by modeling land use changes intended to mitigate possible climate change using a GIS, an assessment of the impact and the cost-effectiveness of different state or national legislative policies can be obtained.

For more information, contact Erich D. Guy, Department of Geological Sciences, Ohio State University (E-mail: erichguy@hotmail.com), or Norman S. Levine, Department of Geology, Bowling Green State University (E-mail: levinen@bgnet.bgsu.edu).

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