Most ecological disruption doesn't take place at the margins of consumer choice. The ecological costs incurred by the average person in the developed world has little to do with whether they choose one product over another, and much to do with the fact that they live in a certain city with certain kinds of infrastructure and a service or industrial base structured in a certain way. Buying an hybrid car has, of course, some impact on their carbon footprint, but a shift away from fossil fuels is impossible without multibillion investments on renewable energy plants and energy grids over which individual consumers have little to no control.

In a parallel way, the rainforests aren't being destroyed to make supermarket paper bags, but rather because destructive agricultural practices are the most economically convenient (and sometimes the only available ones) in some developing countries. Massive investment and technology transfer programs would make a difference, but, again, this isn't something consumers can influence with their purchase choices.

The cultural paradigm change that has made it an almost unspoken requirement that you, by yourself, have to 'do something' to help the planet, might actually be counterproductive by grossly overestimating what most of us can do as individual economic actors. Or perhaps not — without a certain trust on our possibility to affect an outcome, it's very emotionally tempting to dismiss an issue until it becomes catastrophically unavoidable. But much like someone throwing glasses of water at a burning building, we can be helpful in a concrete way without being helpful in a meaningful way.

The fact is that most of our interrelated and growing ecological, energy, and food problems are structural in nature, and their solution requires large-scale changes that are mostly not on the menu for individual consumers. Buying a green car or a solar charger for an iPhone are consumer options, but building a public fleet of electric buses or radically changing land management regulations aren't.

But economic actions are just one of the available levers; there is also politics. Structural solutions, which are required if we are to solve our structural problems, need sustained levels of political commitment from voters. Health, prosperity, and safety are unsustainable without functioning energy and ecological infrastructures, but that fact has limited political impact until politicians have come to the conclusion that, irregardless of other issues, counterproductive or even ineffective actions in those fronts will be career enders. It's clear that in most countries we are still far away from this situation.

As slow, indirect and often unsatisfactory a mechanism of action as grassroots politics can be, it's simply an unavoidable one. Ultimately, the practical effect of buying green is minor compared to that of voting, whatever the specific party affiliation of your chosen candidates, with a healthy dose of self-defense green.