The impacts of the U.S. transportation and electricity generation sectors include air emissions and water consumption. Information and communication technologies (ICT) such as advanced video teleconferencing have the potential to displace some activities that have historically required transportation. While ICT can reduce environmental impacts compared to transportation options in many cases, there are non-obvious environmental trade-offs associated with replacing transportation with ICT. These tradeoffs are the consequence of many factors, including the particular local electricity mix, meeting duration, number of meeting participants, travel distances, travel modes, motive transport conversion technologies, and transport fuels. Identifying and quantifying these trade-offs is the focus of this research. For this study, a nomenclature and methodology were developed to compare environmental trade-offs associated with transportation and ICT. The nomenclature was designed to facilitate side-by-side comparison of the environmental impacts of travel and ICT and to allow expansion of the nomenclature for future study. The methodology considered a variety of conversion technologies for motive transport including spark-ignition, compression-ignition, fuel cells, and electric motors. Both conventional and developing fuels were considered including gasoline, ethanol, diesel, biodiesel, natural gas, hydrogen, and electricity. Likewise, electricity consumption for ICT included both traditional and developing electricity generation technologies. Carbon dioxide emissions and water consumption for ICT were assessed for comparison with transportation in a case study that demonstrated use of this methodology by considering three distinct scenarios for a particular business meeting: 1. Two meeting attendees travel to the meeting by diesel city bus while two travel in a private vehicle. 2. All four meeting attendees travel by private vehicle powered by compressed natural gas. 3. The four meeting attendees do not travel, but instead meet their clients virtually via ICT. The case study analyzed in this manuscript considers only the water and carbon dioxide impacts, but the nomenclature developed allows future expansion for analysis of other greenhouse gases. The three scenarios revealed that, compared to short travel distances, use of ICT does not always generate fewer carbon dioxide emissions. Depending on the mode of electricity generation, travel proved to be preferable from an emissions standpoint for scenarios in which travel distances were small. However, in cases that required long distances to travel, ICT often allowed businesses and individuals to reduce their environmental impacts, especially if electric power generation in that location utilized large amounts of relatively low-emissions technologies such as hydroelectric dams, wind, solar, and nuclear. Finally, it should be noted that, in addition to comparing ICT and travel impacts, this methodology can be used to calculate the environmental tradeoffs of various transportation options when travel is a necessity.
A solar air-cooled high efficiency absorption system in dry hot climates: Reduction of water consumption and environmental impact
