Perhaps one of the trickiest problems at hand is that of our own psychology. To understand what I mean by that, it is worth taking a look at the theory of cognitive dissonance. It states that we find it unpleasant if there is a mismatch - a dissonance - between two of our thoughts, or between our beliefs and our actions. In order to reduce this dissonance, we will - perhaps subconsciously - try to change our beliefs or our actions, or to find some sort of justification for them. As an example, if someone who likes smoking reads an article about the risks of lung cancer, he will tend to take it much less seriously than a non-smoker.
What, now, is the relevance of this idea for us? Of course, it applies to the way we think about our economy and our lifestyle as well. In this blog, I am putting forward ideas that fundamentally challenge the way we live today. Nonetheless, most readers of this blog are presumably not fundamentally changing their lifestyle, because that is no easy thing to do, and the life we live is, after all, until now quite convenient. (The same applies to me, by the way.) If you do believe that we have a problem in terms of sustainability, this is, of course, a dissonance. In order to alleviate it, since leading a completely different life is far from easy, I would suppose that our subconscious will try to play down the seriousness of the problems we're facing. At least I find myself unable to continually be seriously worried about the future of the planet and at the same time not lead a much more modest life. For now, I am managing by being less worried. (There's just this nagging feeling that in a couple of decades, it might turn out that the better alleviation of the dissonance would have been the other way round...)
So what can we conclude from this point? If we take the idea of cognitive dissonance seriously, it may mean that we can't just count on everyone realizing what the problem is, what needs to be done, and acting accordingly (what I dubbed the "bottom-up" approach). In the end, the most effective trigger to get people to change their behaviour will probably be simple financial pressure. For example, I suppose that the amount of mobility we are enjoying today in industrialized societies is not sustainable, and I expect our mobility to decrease in the long run. Nevertheless, I am enjoying it as well, and am not keen on giving it up (thereby feeding back on my own beliefs - "Hey, holiday trips around half the globe aren't that bad after all..."). If, on the other hand, unlimited mobility just got unaffordably expensive, that would probably foster a more sustainable attitude of "Pah, who needs to travel 10.000 miles for a vacation, it's nice near home as well!".
What I therefore deem necessary is a reconciliation of economy and ecology. What is unsunstainable must become expensive (if it isn't already), and what is sustainable needs to be economical, too. While I am not knowledgeable enough to propose a framework that would guarantee this, I see at least two aspects that it should incorporate: Firstly, the price of every good and service should fully and without exception reflect all the energy and raw material costs that were incurred in its production. (This is probably already true to a large extent, but it should become completely true without any dilution by subsidies/lower taxes for energy-intensive industries, marketing-related price lowerings, and the like). Secondly, it must not be possible any more to "externalize" negative effects on the environment, e.g. emissions, without them being reflected in the price of a good. Means towards an internalization of such external costs can be trading CO2 emission rights, and similar measures.
While I'm in no position to single-handedly work towards an implementation of such approaches, I am hoping that there are politicians who see the problem, are strong enough to fight their own cognitive dissonance, are willing to do the necessary, and able to convince the people of its necessity. As stated before, 2009 is an election year. Whoever does the best job adressing these issues in their election campaign has a good chance to win my vote.