Haven’t had enough on offsets yet? Good. Romm’s zeroth rule of carbon offsets is that you should "do everything reasonably possible to reduce your own emissions" before buying offsets. At first blush, this reads like a memo from Obviousland, a staunch statement in favor of apple pie. Pretty much every marketer of carbon offsets heavily stresses that offset purchases should go hand-in-hand with serious attempts at conservation, and I certainly agree.

So far, so good. But the rest of the post serves as a lesson in what can happen when common sense hardens into ideology. After making a bunch of points about how the worst thing you can do is actually feel good about purchasing offsets, Romm offers up Exhibit A of the wrong way to go about buying offsets: Google.

Google is an odd choice of environmental villain for a couple of reasons. The first is that, though the company is not necessarily a green angel, it does appear to be sincere about its efforts to grapple with climate change. Without even hitting, well, Google to look up the info, I can think of a half dozen initiatives the company has undertaken to directly reduce greenhouse-gas emissions. Some are splashy, like putting up the largest U.S. solar array on a corporate campus. Others are far less sexy but probably more important, such as pushing for industry-wide power supply standards that could save billions in wasted kilowatt-hours per year.

More importantly, Google just isn’t a carbon offset kind of company. The cultural bent of the place is to find innovative, do-it-yourself solutions, such as their funky R&D project to develop vehicle-to-grid technology for a fleet of plug-in hybrids. My overriding sense with Google is that they came to offsets only reluctantly after realizing that they didn’t have any other options for achieving near-term carbon neutrality. Their own announcement describes the offset purchase as a strictly "temporary" part of a three-part strategy that puts efficiency and renewables first.

So what’s the problem? According to Romm, the offset purchase is invalid because the company "runs on coal power." This is an extremely loaded way of saying that the company uses electricity, and in America electricity mostly comes from coal. Further, because Google is growing, it is using more electricity than it did in the past. Romm isn’t even accusing Google of using electricity inefficiently. They just use it, period, and this is bad.

OK, fair enough, but where are we meant to go with this? How does the zeroth rule apply? Presumably Google isn’t going to stop building server farms. Would the world be better off if Google didn’t make an offset purchase? And aren’t offsets that support renewable energy production a fairly direct way to address the very infrastructural problem — coal-generated electricity — that Romm is unhappy about?

My point here is not to open up a debate on where Google should site its server farms — a decision no doubt influenced by dozens of factors of considerable importance to the company — but rather to suggest that such debates are likely to be fruitless. The zeroth "rule" is better formulated as a common sense guide: strive to reduce your carbon footprint in as many ways as is practicable, and seek continuous improvements over time. Measure and monitor, and as your direct emissions shrink, so too will any need for offsets.