I don't want to be rude but I think discussing eco-friendliness of polyester, epoxy or even glass fibers is a little misleading. Let's face it: They are all pretty harmful to the environment at some point in their life cycle. Probably just as harmful as smearing a boat hull with tar like it used to be done 100 years ago…
This doesn't mean I don't care about our environment but I think there are many better ways to reduce one's carbon footprint: bicycling instead of driving, flying less, paddling within proximity of your home, etc.

I think you're preaching a bit to the choir. People who come to this board are pretty eco-minded I think in general. We would rather build a wooden boat than purchase a plastic tub made in China. We all paddle kayaks and canoes and not motor around in power boats or jet skis (again, in general). Our wooden boats are going to be kept, treasured and used for years. Hopefully for generations.

We can probably all agree that polyester and epoxy resins, fiberglass, carbon fiber, Kelvar and most boat-building supplies are bad for the environment. Most are petrol-derived and/or take an exorbitant amount of energy for their manufacturing. Fact. All wood boats are possible but for most builders, another fact is we're still going to use these materials to build our kayaks. There are ways to reduce the amount of them that we use but some can not be replaced. So a good option is to look at different materials. Using a partially bio-based epoxy in lieu of petrol-based one is a step. It's a very small step, but still a step.

Let's talk vacuum-bagging and infusion. We can all agree that they are great ways to create light layups. They are also incredibly wasteful. Think about it. Both methods may save a some epoxy but how many yards of peel ply, breather and film are put in a landfill? All of them are petrol-derived.

I've been looking at different ways to minimize the impact of the boats I build in my shop for years. I use local-sourced lumber when possible, often from our own land and am always willing to try alternative materials. I switched to bio epoxy about three years ago. I started with Ecopoxy (not bad epoxy but horrible customer service at the time) and now use 100% Entropy Super Sap. About five years ago I tried a water-borne marine finish (got burned on two builds by it) and now use a solvent-based automotive finish with less VOC's than some water-bornes.

Ok, rant done...