Technology and the Environment DD's Eco Notes

In my last post on carbon offsets, we looked at various aspects of "space shifting", or the practice of emitting CO2 in one location and offsetting in another. In that I asked whether this really worked in practice, and I got some excellent comments and emails that indicate that it does.

I got a number of people suggesting that CO2 mixed pretty quickly, but the most direct was from Marcus Sarofim at MIT, the CO2 in the earth's atmosphere mixes every 1 to 2 months within a hemisphere, and 1 to 2 years between hemispheres. This is far less than the time the CO2 is in the atmosphere, and also far less than the 70 years of productive CO2 sequestration from our trees, so it sounds like this is not a concern! (Marcus cites this report, and notes that this is not true for other green house gasses, so space shifting may not be as viable for those).

So it looks like space shifting is OK for CO2!

Another thing I questioned in that post was the ability for trees planted in the northern hemisphere to be good sequester-ers of CO2. Marcus and others argued that the potential issue is an albedo effect where the dark trees absorb more heat than the open space they replaced. However, this report from the EPA indicates that there are a number of factors at work, and that the amount is limited by how much you want to spend managing the planted trees. In particular, at $5 per ton of CO2, the capacity for CO2 sequestration due to new forests in the US is very limited.

The next post we'll take a look at whether sequestration projects such as Dell's can scale....

Check out InfoWorld's "12 crackpot ideas that just might work", especially slide 13.

It's great to see the level of dialogue about the environment continuing to grow within Sun. Here's a few recent links and notes:

• First, we're getting tremendous response from our first CSR report. It's causing discussion inside the company and with many of our external stakeholders. Congrats to Marcy and the team who did a great job pulling it together. This will be updated annually, with the next release in the fall (we're going to get on a schedule to match our annual financial report).
• Valdis Filks writes about what he's doing at home, and sets a great example. Share your success stories!
• Valdis also writes about the environmental costs of tape and disk. In recent presentations I've been saying that tape/disk is the next killer hybrid. Just like the Prius uses gas and electric motors to complement each other, tape and disk can fill a similar role, and with similar eco results. Stay tuned - more to come from our storage team on this.
• Tim Bray gets a strongly worded comment for taking a trip down to Sun's headquarters to meet with a software VIP. I can't judge whether Tim's trip was worth the CO2, or whether Tom's in any position to criticize someone about taking a business trip. But it raises a key question: how much are we going to have to scale back the economy as we know it today in order to get to a sustainable model? I hope to write some about this this spring.

Next post will be back to our regularly scheduled CO2 discussion.

Sorry to those of you who've written comments over the last few months. I discovered today that I wasn't getting the emails that comments were in the queue waiting for may approval, so they've just been sitting there. I think I have it working now...

While I've been dealing with the theoretical aspects of CO2 emissions, lots has been going on in the real world (as the gamers say). Gill Friend summarizes it all here.

Following the last part in this series where we looked at times shifting of CO2 offsets (offsetting the CO2 at a different time that it was emitted), in this post we'll look at space shifting, or offsetting the CO2 at a different place than it was emitted.

Dell's program involves planting trees in order to sequester the CO2 due to PC usage. The CO2 emissions will occur at a power plant somewhere near where you're using the PC (although with today's power grids it may not be all that close). Dell's program is in partnership with the Conservation Fund who plants trees throughout the US. Through their overall program they've planted around 5.5M acres (not all of this is for offsetting purposes, though it still helps), 3M in the west, 1M in New England, and the rest in the southeast, midwest and Rocky Mountain region.

At this surface this looks pretty reasonable - sequestration is spread across the same area where emissions are occurring. However, we notice that 60% or so of the emissions are in the west, and only 20% of the US population is there. So this raises an obvious question: can the western US sequester CO2 emitted in the east, midwest and south? Or, more generally, if can we space-shift CO2 offsets? Or (I can't resist) if a tree grows in the forest and there's no emitters around, does it sequester?

I've spent the last couple of weeks looking into this question, and I've come up empty. If someone has done real science on this, please let me know, but I can't even find anyone asking the question.

This question is important to ask. There are reports that trees planted outside of the tropics may not be a net reduction of CO2. There's a bunch of CO2 offset projects which reduce CO2 in developing nations and sell the offsets in developed ones. So in an extreme case, you can ask yourself this: would carbon offsets work if all of the offset projects were in South America and Africa, and all of the credits were sold in North America, Europe and Asia?

Anyone?