I've come across some interesting documents recently, all of which are available for free online.
The Bicycle and Urban Sustainability by David Tomlinson, who in 2003 was at York University, and now seems to be with the City of Toronto Transportation Services.
Mr. Tomlinson does a good survey of why modern cities are not sustainable and how the bicycle can come to the rescue. At one point, talking about auto accidents he uses the sentence While the carnage inflicted by automobiles certainly changes the lives of countless crash victims and their families, the fear of traffic accidents can affect everyday travel choices. That's a fairly sad sentence on many levels, but for cyclists it is sad because Tomlinson goes on to explain that it is primarily the "fear" of being in an accident that keeps people from choosing to ride their bike to work.
He also mentions this idea, which I'd actually never heard before:
Short automobile trips generate the most pollution, per kilometre, since a vehicle’s motor is not able reach optimal operating temperature. These are also the trips that are most amenable to bicycling, and so the bicycle’s potential to reduce air pollution is higher than one might think.
The Earth Policy Institute has a text titled Plan B 2.0: Rescuing a Planet Under Stress and a Civilization in Trouble. They've made it available as a .pdf on their website.
I so far haven't reached the chapters where "solutions" are presented. Right now I'm just reading horror story after horror story about how we're all doomed.
It's nothing new I guess - the peak oil issue, the looming water crisis (which will probably start a war in the middle east), the loss of farmland to suburban sprawl, etc. etc. It's scary stuff, so eventually you can't take anymore and you close the book and you open one of your magazines....
and you read in Fareed Zakaria's Newsweek column that China and India are already constructing 650 coal-fired power plants, whose combined CO2 emissions will be five times the total savings envisioned by the Kyoto accords.
FINALLY, Statistics Canada has a good publication titled Human Activity and the Environment: Annual Statistics 2006. Section 1.2 documents Transportation's Environmental Impacts, and there is basically a chart which says "Cars kill us this way, this way, and this way" (page 18, and I'm only exaggerating a little bit).