Systemic economic change

I've been following this line of thought in regards to environmental limits and growth which basically revolves around 'do less, conserve more'. There's some merit to the idea, which I think is summed up by the idea of hard environmental limits. Now, the difficulty becomes in discerning what those limits actually are, vs what we think they are.
This is most obvious currently in discussions about atmospheric CO2 concentration. Will we cook the grandkids or did we head off an ice age (Now, to be honest, I just did a quick search, and I was not able to quickly find a coherent and well-put argument that we headed of an ice age). The point here isn't which 'side' of the debate you are on.. but how do we as a global community come to a consensus on what the acceptable atmospheric CO2 concentration is? Both extremes (human extinction) to (what, me worry?) are rather naive. There's a range in the middle that's realistic, and frankly, I don't have the foggiest idea what is the right CO2 setpoint.
The hard environmental limit that's much more interesting to me is Nitrogen intensity. Higher nitrogen intensity has a side-effect of promoting biomass growth, which in turn ties up more atmospheric carbon. I try very hard to be conscious of the many different sides of these arguments, and the conclusion I come to is that while most other resources and economies require a 'do less, use less' going forward, there are a couple of major exceptions, in which exponential 10% per year economic growth is not only possible, but absolutely necessary for the rest of the world to be able to make systemic economic change a reality. These things are, in order of increasing growth and monetizable return potential (aka, Venture Capitial investor attractiveness):

• Direct farm-to-table markets. This is the downtown farmers markets, and all kinds of new ideas which have yet to be developed and deployed. But they will be small-scale, small-business, and local oriented. Bottom-up approaches that come out of social interactions made possible by the global social networking software in bullet 2.
• Information/software/computer technology. Every product cycle, we pack more transistors on the same area of silicon, and this makes the resulting computing devices, software, and user applications more effective, capable, and productive using less resources for the same work as the last product cycle. Now mind you, the total work keeps increasing, so the end result is a slight uptick in net electrical power usage.. This is no problem, so long as the electricity is new renewable generation. (see bullet 3)
  
• Wind energy. Even with a 15% discount rate, wind energy has a net Energy Return on Investment (EROI) of better than 6.. and gets better the lower the discount rate is. In other words, if you want long-term energy production, put up a wind turbine. Then your problem is that wind energy is generally not close to the existing loads. So exporting wind energy as bits on a fiber optic line (bullet 2), or as tankers of ammonia (bullet 4), now we've decoupled the location from the point of use, just like oil has allowed huge economic growth for the first half of the 20th century.
• Electrically driven NH3 (ammonia) production. I'm putting my time and energy into Freedom Fertilizer because every indication I have is that this is going to be possibly the only growth area in anything that resembles large industry. There will be huge new economies created with what I reference in bullet 1. But NH3 is the only large scale thing I have come across in which the fundamental physics of mass transport and energy availability actually work out. Maybe someday WindFuels will work out, but this requires a point high concentration CO2 source. Ammonia needs air (78% Nitrogen), water (Hydrogen), and wind (energy). And with the available energy, taking 'dirty' water and distilling it is a very minor cost compared to getting the hydrogen out.