The environmentalist movement emerged in the 1970s as the coordination of local grass-root protests, under the motto "think globally, act locally". At the time, and still today, many actions supporting environmental sustainability can be implemented at local or regional level, with minimal need to coordinate with others. The action, the costs and the benefits remain localised. Examples of such actions can be: urban planning supporting active modes of mobility (cycling, pedestrians), prevention of water pollution, or the NIMBY-type resistance to any form of infrastructure or equipment. There is a contemporary appeal in this vision of self-regulated micro-communities which would be living peacefully alongside each other and coordinating freely using the Internet, as the ultimate utopia of anarcho-libertarianism popular on the US West Coast.
The challenges of the 21st century however are global1: the action in one place has effects elsewhere. The main illustration of this situation is climate change, where all humans share one atmosphere, and one common Greenhouse Gases Emissions budget within which we must remain to maintain climate change below 1.5 or 2°C. In this situation, the myriad of micro-communities mentioned above would need to be made of perfectly informed saints to spontaneously converge towards a fair sharing of this budget, and to comply with it. Every community, if left to itself, has an excuse to do less efforts, and to expect the others to do more, and even an incentive not to comply with its commitments: by being the first to do so, they benefit from the efforts of the others, and don't bear the costs. This is known in game theory as "free riding", and is verified by the current behaviour of the existing nation-states following the Paris Agreement of 2015: when summed up, the commitments of all the parties lead to a climate change of 3°C, way above the target2. There is no reason why micro-communities would behave better than nation-states.
This illustrates the main, massive drawback of the anarcho-libertarian vision of freely coordinating micro-communities: the lack of coordination and agreement between these micro-communities, including the capacity to enforce agreements once made, as highlighted in our Manifesto. The larger the number of entities to coordinate, the more difficult the coordination. Only large-scale political institutions have the capacity to establish a common, agreed-upon set of rules, and to have them implemented. In the absence of such agreement, conflicts escalate into violence and war. As an illustration, the populations in the highlands of Papua-New Guinea until the 1940s had been divided into thousands of small independent village communities, which fought endless vendettas with a mortality rate superior to that of Europe during the World Wars. This situation has been that of humans during most of their history and pre-history. When the Dutch administrators arrived, the inhabitants submitted very easily to this neutral, external power, from which they expected, and obtained, lasting peace3.
Said differently: a political situation made of multiple, small-scale, independent communities has already been tried in the past, and failed, despite having been attempted over millennia of human history and pre-history. This failure is not due to a lack of technology (and thus cannot be palliated by a tool such as the Internet). It is intrinsic to the fact that independent communities have no institution to make them peacefully agree in case of conflict, so that they end up in permanent war – with no time nor energy to dedicate to larger-scale issues such as climate change or any of the global challenges of the 21st century.
1Some of which are illustrated in the Manifesto of the CosmoPolitical Party: the unsustainable "Western" life-style, population ageing, inequalities brought by integrated technical systems, the power of multinational corporations, the spread of poverty and precariousness, migrations.
3Diamond, J.: "The World Until Yesterday: What Can We Learn from Traditional Societies?", Viking books, New York, 2012 - http://www.jareddiamond.org/Jared_Diamond/The_World_Until_Yesterday.html