Friday, October 12, 2007

Tim Flannery makes a mistake

This is interesting. According to this post at the Real Climate site (which is, after all, run by Al Gore supporting, actual climate scientists), Tim Flannery's claim this week about greenhouse gases reaching a certain disastrous level ahead of schedule is simply wrong. It appears he got confused by the terminology:
There was a minor kerfuffle in recent days over claims by Tim Flannery (author of "The Weather Makers") that new information from the upcoming IPCC synthesis report will show that we have reached 455 ppmv CO2_equivalent 10 years ahead of schedule, with predictable implications. This is confused and incorrect, but the definitions of CO2_e, why one would use it and what the relevant level is, are all highly uncertain in many peoples' minds.
There follows a run down as to how to understand the terminology correctly, which I won't bother reprinting here. The penultimate paragraph says:
The important number is CO2_e (Total) which is around 375 ppmv. Stabilisation scenarios of 450 ppmv or 550 ppmv are therefore still within reach. Claims that we have passed the first target are simply incorrect, however, that is not to say they are easily achievable. It is even more of a stretch to state that we have all of a sudden gone past the 'dangerous' level. It is still not clear what that level is, but if you take a conventional 450 ppmv CO2_e value (which will lead to a net equilibrium warming of ~ 2 deg C above pre-industrial levels), we are still a number of years from that, and we have (probably) not yet committed ourselves to reaching it.
The final paragraph comes close to direct criticism of Flannery:
....this is another example where people are quoting from draft reports that they have neither properly read nor understood and for which better informed opinion is not immediately available. I wish journalists and editors would resist the temptation to jump on leaks like this (though I know it's hard). The situation is confusing enough without adding to it unintentionally.
I will wait for Tim's retraction (or, at the very least, clarification) to be made and appear in the media. (Cue crickets chirping.)

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