Sunday, April 20, 2008

Saul Griffith’s Carbon Footprints Part II – Some numbers

Following my previous post, I thought to look at Saul’s energy usage / carbon footprint calculations by separating out his personal energy usage from his work related consumption.

See the notes below on how I have separated the work from the personal energy usage. The chart below separates out the numbers into 4 categories, and speaks for itself. Almost half of Saul’s home energy usage comes from “Food and Stuff” which represents the embodied emissions of his consumer purchases. Of course, as Saul has pointed out, he has probably underestimated the energy usage associated with these categories.

Again, people can dispute the difficulty of calculating the embodied emissions of “stuff”, but at almost 4 times the energy usage of his home heat and electricity, Saul’s calculations should at least, again, put the importance of embodied emissions in perspective.

A few other notes:
  • Like the truck driver in my previous post, Saul’s major source of carbon emissions relates to his travel for work. His total work related energy use should be compared to the value of his work, in revenues from his company or at least with the costs associated with the company. This figure should be compared to other businesses in the same sector.
  • Energy usage of ‘stuff’ related to work would probably need to be more comprehensive, including things like capital goods (servers, furniture), services delivered to his workplace (fedex, as well as consumables (like pencils and paper and printer toner.)
  • Here is the data:
Some notes on separating work from home usage:
  • Saul mentions that most of his air travel is for work, so I put in a “wild guess” number of 90% related to work. Inversely, I assumed 90% of his car usage was for personal (ie home) use.
  • In stuff, I only allocated his laptop to work. As noted above, there are probably other work related goods that should be added to his work “stuff”
  • The allocation of societal consumption is an interesting one. Here I have assumed it is half for work and half for home. After all, government exists to serve both individuals and to support businesses. Although the actual impact at ~3% in total is not very big, a more thoughtful method may still be needed here. For example, there could be an argument that government is there only to serve the people, so 100% should be allocated to individuals. At the same, this would distort the picture for developing nations (and the goods they export), especially since substantial government resources are probably expended on supporting businesses.


Tuesday, April 15, 2008

Saul Griffith’s Carbon Footprints Part I – More on Consumer vs Producer Responsibility

“Power Consumption at work... This... brings up a very interesting point... where do you draw the lines in figuring out your own energy consumption? Does work energy go against you or the product of that work?”
Saul Griffith’s excellent presentation gives a very thorough view of carbon foot-printing, and the particular question above is quite fundamental. I would argue that personal energy consumption should be treated separately from energy use for work. The energy use related to our work should show up embodied in the product of our work.

A few examples could help illustrate why…
  1. Say I am truck driver that delivers apples ( ;-) ) to a local grocery store. It would not make sense to mix my personal energy consumption behavior with my job as a truck driver. Even if I lead a carbon neutral personal life, mixing my stellar home footprint and my work related emissions would give a distorted view of the choices I can make – ie the factors which are under my control, in my personal life.
  2. Now let’s imagine the exact opposite case. Let’s say you are a small business owner, doing most of your work from the office using emails and phones. Again, you could be driving a hummer from home to work, and leave your oven on 24 hours a day, but if you mix your personal and work energy usage, you would still seem more eco-friendly than the me.
  3. Now, to drive the point home, imagine that you are my boss, and you are responsible for deciding the kind of truck I would drive. Clearly, the distortion created by mixing personal and professional energy use and footprints would make the exercise quite meaningless.
This is not to say we shouldn’t worry about our work related energy use. All of us have some say in the energy consumption of our workplace. And we can make choices to affect it. But the energy consumption of my apple delivery business should be compared with the energy consumption of other apple delivery businesses, or delivery businesses in general. The result of our work, and the energy we consume to deliver it, would both be manifested in the product of our work – in this case, an apple. So it would also make sense to use metrics like CO2 emissions per apple delivered…

Or, for practical purposes, so as to be able to generalize (and mix apples and oranges in the same truck), one could measure, CO2 per dollar of revenue delivered…

Or rather, to be able to account for each business’s share of economic activity, carbon emissions per dollar of economic value add.

(To illustrate: Let’s assume I have an apple delivery business using apples from my brother’s farm. And say you have an apple farm and deliver the apples yourself. Ultimately, we would want to compare the total lifecycle emissions for each apple. Say, you sell apples for $2 and emit 2 grams of carbon per apple, from the farm to the final delivery. My brother emits one gram of carbon per apple and sells them to me for $1. If I emit 1 gram of carbon in delivering the apples and sell them for $2, the total embodied emissions of the apples I sell are the same as yours – 2 grams in total. But if I calculate emissions per dollar of revenue, I would get 0.5 grams of emissions for every dollar of revenue – ie 1 gram for every $2 apple – which is the wrong comparison. In effect, I am emitting 1 gram for every $1 of economic value add, since I am buying the apples for $1.)

So, the best way to compare apples and apples is to compare the total embodied emissions in each product, including each part of the full supply chain, preferably in the form of a carbon label. And each part of the supply chain would weigh its emissions against the economic value that it is adding to the product, and compare that to similar businesses - ie comparing apple delivery to apple delivery.

From a consumer responsibility perspective, it would be up to each apple buyer to decide between different kinds of apples and take responsibility for that purchase decision. If an apple delivery company decides to use solar powered trucks, then that should show up on the carbon label of the apples it delivers, and affect the carbon footprint of the buyers of those apples.

Many argue that carbon labels are impractical because the carbon footprint of each product is very hard to calculate. I don’t believe that to be the case, especially if you weigh that difficulty against the total impact of embodied emissions (also see here and here.)


Sunday, April 06, 2008

Carbon Emissions in Developing Countries: Producer vs Consumer Responsibility

“Developing countries, whose economies and populations are growing fastest, [will] contribute 74% of the increase in global primary energy use [until 2030]. China and India alone account for 45% of this increase.”
World Energy Outlook 2007, IEA

So three quarters of all new power production capacity will be in developing countries. Close to half of it in India and China. And according to the same report:

China, with four times as many people, overtakes the United States to become the world’s largest energy consumer soon after 2010. In 2005, US demand was more than one third larger.”


“In the longer term, [in China,] demand slows as the economy matures, the structure of output shifts towards less energy-intensive activities and more energy-efficient technologies are introduced.”
This last sentence is the most interesting. It sounds like the basic assumption of the report is that China will make a typical progression towards a more advanced economy: As the country becomes richer, not only will it care more about the environment and prioritize more energy efficient technologies, but the economy as a whole will become more service oriented, much like that of the US. Of course, this does not mean that the world will consume fewer goods. It just means that those goods will be produced in a new generation of up and coming developing nations – and those nations would account for the ~30% of the total increased energy use until 2030.

One could imagine that, like China today, those countries will want to use the cheapest (and thus potentially the dirtiest) fuels. They might also argue that it would be unfair to impose environmental restrictions on them since they too have a right to grow their economies. Just as China points to Europe and America’s growth and how they were fueled by dirty coal, those countries may point to China along with Europe and America and make the same argument.

And from their perspective, they would be right, just as China is “right” in its argument today.

The problem is the paradigm upon which the argument relies. It is a “producer responsibility” paradigm of CO2 emissions, looking at emissions based on where they were produced or emitted, not on why they are produced, and for whom. The "producer responsibility" world view ignores the "end-user" or consumer of the products which were created using those emissions.

Many developing countries, especially in their early stages of development, rely heavily on exports. In effect, they are using much of that new energy capacity to produce goods which are consumed in the more advanced economies. A “consumer responsibility” approach to carbon emissions could create a paradigm shift. It could give consumers the leverage to make decisions on whether they want to buy products which were produced using say, a new coal fired power plant. And it would shift the debate away from esoteric arguments about the "right" of government bureaucrats to pursue their nations' best interests.