It takes a lot to run a data center—equipment and peripherals, cabling, toner/ink, and, yes, even paper. And a lot of it needs to be upgraded or replaced at least once a year. (Say what you want about a printing press, but at least it can last for decades.) As a result, e-waste is a growing problem. Says Environmental Leader:

E-waste, a major component of data center material flow, represents the fastest growing municipal waste flow in the U.S. and likely around the globe with recent reports indicating an 8.6 percent growth rate. In 2007 alone over 41 million computers were discarded in the U.S. – with only 18 percent being properly recycled.

Even worse, a lot of it is exported to third-world countries where it contaminates the environment, causing health and other problems. Things may get worse as more and more companies’ data centers accelerate their replacement schedules to improve energy efficiency and other advantages to be had with newer gear. How to deal with this hardware “churn” in an environmentally friendly way? To go some distance toward coming up with an answer, what is needed first is a metric. What is the gauge for sustainability? What do you measure and how do you measure it? A position paper (link opens PDF) from Emerson Network Power positions “recycling ratios” as one thing to gauge. They define two specific recycling ratios:

Material Reclamation Ratio. MRR is the ratio of: Recycled/reclaimed/repurposed material (expressed in mass) over the inbound (received) material less outbound finished goods and services (also expressed as mass). The result of the equation would be a ratio expressed as a percentage – with 100 percent recognized as the goal. Companies achiev- ing a 100 percent MRR have zero waste. ... MRE – Material Reuse Effectiveness. MRE is expressed as: Inbound (received) material less outbound finished goods and services, expressed as mass over the recycled/re claimed/repurposed material (again expressed in mass). Just as PUE is expressed as a ratio, with overall efficiency improving as the quotient decreases toward 1, MRE also provides a goal of 1.

PUE, by the by, stands for “power usage effectiveness,” a now-standard way of measuring a data center’s energy inputs and outputs. The idea behind these ratios is to track progress over time. There are some online calculators to give you an idea of how they would work. We in the printing industry get repeatedly castigated for causing “environmental carnage,” but goals like “zero-waste data centers” are a reminder that all forms of communication, media, and business activities have environmental costs that must be dealt with.