Carbon footprint of a banner ad? What the heck?

If somebody walks up to you in this holiday season and asks this question “How would you calculate the carbon footprint of a banner ad”; you should immediately check what he has been drinking. And if you are one of those adventurous types, order one of that for yourself. Because it has to be some really strong stuff that makes ones mind wander in such directions.

But this is precisely what Don Carli of Sustainable Advertising Partnership is trying to figure out. Carbon footprint, as most of you would be aware, is a measure of the impact of human activities on the environment. Don’s organization is trying to bring the advertisers and the supply chain (for all kinds of media, such as print, online, TV) together to come up with best practices for advertising; best practices that would address the challenges of sustainability and make the ads more “green”, so to speak.

Don has been involved in such initiatives for over four years now (at least, that’s what his LinkedIn profile tells me) and since it’s highly unlikely that he has been constantly inebriated all these years, you have to take his question a bit more seriously. Personally, I don’t think it’s important. If I’ve to make a list of all the stuff for which we need to reduce the carbon footprint, “banner ads” perhaps won’t figure among the first hundred billion entries in the list. But Don apparently belongs to the group of folks who believe in the age old saying that ‘every bit saved makes it a bit more’ (or words to that effect). So let’s give this question a shot.

To calculate the carbon footprint of a banner ad, we have to measure the energy consumed at each stage of the supply chain for creating, storing and serving the ad. So what exactly is the “supply chain” for serving the banner ads? Lets see who are the players involved:
1. The Advertiser
2. The creative agency (these folks design and develop the “creatives” or display ads)
3. The Ad agency (they work as the intermediary between the advertisers and publishers/ ad network)
4. The Ad network (someone like Yahoo or Double Click, who has got a pool of publishers)
5. The Publisher
6. The Content delivery network (someone like Akamai, who stores these creative closer to the end users location)
7. The ISP (and the entire internet infrastructure that brings the data to you)
8. The end user

Wow! It’s kind of mind boggling to think of all the systems that are used to serve the ad. For example, take the case of only one of the players in the supply chain, the ad network. It should have systems that help advertisers manage campaigns, book ads, view reports. Additionally, it should have systems to forecast traffic, run pricing models, log events and software to rotate banner ads, if required. All these applications, would most probably, be running on their separate servers (sometimes multiple servers for one application). So how exactly we track the energy consumed by one ad through all these systems.

But hang on a minute. We can make our task much simpler. The end objective is to see if we can reduce the carbon footprint of the banner ad by some optimization in the creative i.e. either by reducing the size of the ad or by optimizing the way it’s served. So we should only consider the systems that are affected by the type or size of the ad. For example, the pricing server would be unaffected by the size of the ad and so would a lot of other systems in the entire supply chain.

Most of the systems in the supply chain would only have a reference to the creative. The actual creative is perhaps used by only a handful of systems. So let’s see in what all systems the creative actually “consumes energy”
1. Systems used by creative agency to create the ads
2. Datacenters by content delivery network that stores the ads
3. Network bandwidth for serving the ads
4. Processing power consumed on users machine when the ad is displayed.

So if we know the average carbon footprint per processing power of the machine, we can allocate some of that to the banner ad depending on how much processing power it takes or how much bandwidth it consumes. In other words

Carbon footprint of banner ad = (Carbon footprint of the server or pc) * (processing power or bandwidth consumed by the banner ad)/ (processing power of the server or pc).

Calculate this for all the systems mentioned above and feel free to use the expression 'Voila' once you get there.

And here comes a disclaimer. Those who have read about cost accounting methods would quickly point out that the “allocation” method described above is perhaps not the optimal way to measure something. But looking at the abstract nature of the problem, this is the best I could think of.