I have been thinking about writing on this topic since early 2006 but did not get a chance. Recently I finally sat down and started thinking again.
“Green” has become a buzz word. Everyone is talking about how to reduce your “carbon footprint”. Hybrid cars are beating traditional gas engine cars in the market (be aware of the smug alert though). Big and small companies are showing off that they are “carbon neutral” by investing into alternative green energy. It is a fact that we (as human beings) are generating carbon dioxide every second, and the stuff to make our life better generates carbon, too – cars, heating and cooling. To make the whole earth planet sustainable, it makes sense to be conservative about our energy and carbon usage, and at the same time, think about creative ways to reverse the process.
There is an interesting story – recently Google was blamed for their excess usage of energy. Research from a Harvard physicist showed that a google search generates 7 grams of CO2, which is about half to boil a kettle of water. Google argued the number is actually much lower. No matter who is right, this is indeed a dilemma. On one hand, Google needs to rely on powerful computing infrastructure to provide satisfatory services. On the other hand, Google wants to be conservative about their energy consumption, which is directly correlated to the scale of computing infrastructure.
In the information technology world, people are referring to infrasturcture consolidation tools (vituralization and cloud vendors for example) as green because they could potentially save energy consumption and make servers more efficient. Many data centers have “gone green” because of its financial benefits.
But really, can we quantify how green our bytes are? Here is a totally simplified scenario.
Say, I have two computers, one laptop and one desktop. The laptop is 80W and the desktop is 250W. If I use each 12 hours per day (which I do), the direct energy used by the computers are (80+250)*12 = 3960 Wh = 3.96 KWh. Assuming I am using grid electricity, this is equavalent to 2.13 kg of CO2 emission. Kind of scary, huh?
On top of direct energy usage, let’s calculate energy on top of that. Assuming I use google 300 times during the day, energy comsumption from Google is about from 60 g to 2100 g, depending on whether Google’s claim is realistic. Since I also use other SaaS products and online applications – twitter, wordpress, gmail, google reader (other Google products), I would suggest they consume rougly the same amount of energy as Google search. So online application costs from 120 g to 4200 g CO2.
On top of that, I want to add the energy used by ISP to send/receive my bytes. Assuming that has the roughly the same weight as online applications. For convenience, I will use valie of half of the max online application energy usage, which is 2100 g CO2.
Our final number is in the range of 4.35 kg and 8.43 kg of CO2 emission for a typical computer user in the US.
In the end, this is the nature of life. We have to live it.
(Please note, the calculation used in this article is unscientific.)
