First, a factual problem of the revisionist history variety to deal with: Not picking on you specifically - everyone, including the media is calling the 5,000 bbl/day estimate "BP's estimate". The 5,000 bbl a day estimate is
*not* BP's estimate, it is the US government's (Coast Guard/NOAA's) estimate. Some people
want it to be BP's estimate so it is easier to claim it is a fabricated number based on bias or even lies (fraud, as claimed before). Now certainly BP would favor low estimates, but a BP bias didn't factor into the creation of that estimate and doesn't even need to factor into BP's usage of that number because that number is still the US government's favored estimate:
http://www.cnn.com/2010/US/05/20/gulf.oil.spill/index.html?hpt=T1
That said, people have alluded to but not thought through some clear "flaws" in the 5,000 bbl a day estimate. Let me finish the thought:
The NOAA/USCG estimate is based on surface measurements and is therefore not a
leak measurement, but is rather a
slick measurement. That's not a flaw it just means it is different from a measurement of the leak and cannot be taken to be a measurement of the leak. The media fed us that number as a "spill" measurement probably because they didn't think of the same issues we didn't initially think of:
1. Some fraction of the oil is not making it to the surface.
2. Some fraction of the oil is evaporating after reaching the surface.
But certainly the USCG/NOAA personnel who made the estimate wouldn't have made that mistake.
Note the Salazar paraphrase above uses the word "leak" - and this is why I prefer direct quotes to media paraphrases, because we don't really know if that word choice is accurate or is just sloppy journalism. If it is accurate, then I'd say odds are good the government has the size of the leak low because if the size of the slick is growing at 5,000 bbl a day, the size of the leak is probably several times larger.
Now when playing the propaganda/blame game, it is important for anti-energy/anti-corporate people to jump on the highest possible estimate, so the 5,000 bbl a day estimate is characterized as "wrong" and Werely's estimates are "best". But the reality is that not only is there currently no reason to believe the estimate is wrong (within the context of the definition of the word "estimate", of course), but it is likely that the surface slick size is
more relevant than the other three numbers (evaporated oil, oil remaining undersea, total). No doubt any proper report will discuss and attempt to pin down all four numbers, but the one that most directly affects ecological damage and cleanup that BP will be made to pay for and will affect residents of the Gulf coast most is the estimate of how big the slick is.
From the same article as above, he was making the talk show rounds with some new numbers this morning: Put into the same terms as his previous estimate, that's 60,000 +-67%. His estimate got slightly larger, but his uncertainty got vastly larger. My confidence level in that estimate was never very high due to immediate instinctive red-flags about how one could use a low-quality video clip to make such an estimate. This only increases my skepticism. But hey: I'm a capitalist, so I didn't fault BP for downplaying the leak size earlier for financial reasons and I don't blame Werely for getting his 15 minutes, while the getting is good, either. I do, however, blame the media for promoting Werely and not doing their homework on him and his estimates. It's kinda funny: reporters are supposed to get three independent confirmations of a fact before printing it, but one "expert" says something provocative and all of the sudden, its gosphel. If they were doing their jobs, they'd get themselves two more experts to make the same measurements and/or comment on the methodology Werely is using.
