17-290 / 19-211 Computers and Society

Homework 7 - due May 3, 2007

1. (a) Identify two ways CMU could change it's computing-related practices to be more environmentally friendly. (b) Select one of these changes and perform a simple analysis to determine what the environmental impact would likely be if this change was made by a particular department or in a particular computing cluster (for example, how much energy would be saved or waste reduced over a given time period?). Make sure you explain how you did your analysis, where you got your numbers, and what assumptions you are making. (c) Are there any downsides to making this change (for example, increased costs, inconvenience, etc.)? Explain. (d) Are there any benefits to making this change beyond the environmental benefits? Explain.

2. Many computers are still usable but the owner upgrades to a new machine before it fails. This is in part due to new technology or performance available and market development. (a) What happens to such machines? Give your estimates of flows based on US experiences. (b) Some fraction of computers are donated to developing regions, e.g., for use in schools. What are the environmental costs and/or benefits of such a transfer? Is it better to deal with end of life issues of computers in the US itself or ship them off to developing regions (and once they get there, it's no longer the concern of the US entity)? Make a stand and back up your viewpoint based on data or references.

“Debate” question:

Sending used US computers to developing regions as *donations* is a good idea or a bad idea? Base your answer on environmental and economic grounds. Consider the perspectives of the US (sending the computers), and the developing country (recipients of the computers). [for and against, each]

*donations are typically for machines that have served their useful purpose for the original user.