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Substantial amounts of air pollution are generated during construction activities. Large volumes of particulate matter and greenhouse gases (GHG's) such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) from fuel combustion and land disturbance are generated. Emissions from construction can represent a large air quality impact that, although temporary in nature, can contribute to the overall release of GHG's in a region. Of the common construction activities, earthmoving that consist of clearing, grading, trenching, soil compaction and cut and fill operation can produce significant amounts of CO2 by disrupting soil aggregates, increasing aeration, incorporating plant residue, and oxidizing soil organic carbon. The amount of CO2 that is sequestered in the soils of a project site varies depending upon the climate of the region, and available vegetation. A preliminary assessment of the project site, prior to construction, to quantify the amount of CO2 stored in the soils will provide a baseline physical condition. Identifying this preliminary condition will provide necessary data to discussions of the projects impact to the environment and the current regulatory criteria that may be relevant.

In the desert southwest of the United States, construction activities generally disturb large segments of sparsely vegetated land. The arid to semi-arid terrain is vegetated by drought resistant species that play a fundamental role in the process of soil formation. Construction activities that disturb these soils reduce the ability of CO2 uptake. This study examines and assesses the amount of stored CO2 in the soils of a project site. A conceptual model of soil disturbance and CO2 release is discussed with emphasis placed on measurement methodologies, soil respiration in desert climates, and cost to construction when considering proposed regulatory regimes.