I won't say that the personal habits of environmentalists have no symbolic value, but it's only a little bit -- and it's meaningless in substantive terms.

Again, why did (you and) Detroit have to run a Hybrid Hype campaign?

Was it becaue the personal habits and decisions of a small group of Americans threatened to change broader attitudes?

It is trivially inexpensive to buy a carbon offset for an airplane ride.

All someone needs to do, especially an environmental author on a 20 city promotional tour, is plant a few trees, or subsidize a few acres of rainforest preservation.

For a book tour it would certainly be positive reinforcement for the book itself (mention it at every stop) and might even plausibly be a promotional expense (ask your accountant).

Wouldn't it be sad if Flannery, expert that he is, had bought offsets, and everyone was frothing hypocrisy without basis?

Not about hypocrisy, but...

Flying as a mode of transport CAN be more efficient than driving (think of all the energy spent on overcoming friction of the road), but currently is not.

Two: while planting trees MAY offset GHGs and preserving forest WILL prevent release of GHGs, it is incredibly important to see that the tree a) survives and b) is not easily decomposable. And preservation of rain forests should be done on its own merit, rather than "off-setting" GHG release by our transportation, since a preserved rainforest does not take up or give off any carbon. Now if the money would be going into restoring rainforest, then we are talking.

"since a preserved rainforest does not take up or give off any carbon"

on a balance. Clearly it gives off and takes it up, but the carbon balance is 0.

   David is right that we should not waste our time eating our own.  Looking for absolute purity is a waste of time.  There is a reason Walmart doesn't carry hair shirts.

   As for air travel, it is going to increase.  All the signs are there.  So, what can be done?  Investment in high speed trains able to compete on short and medium distances would be nice.

   Investment in better or different kinds of engines for airplanes might help.  

   I believe we have the ability to solve these problems, we lack the will.

   We also need to look at institutional practices (corporations, military, universities, churches, unions, NGO's, government) for change.  

   It is a mistake to put all the blame for our problems on individuals.  Nor will individual decisions solve the problems.

Patrick