The "environmentalist" opponents of conventional development projects are not standing against social progress. Their prime motivation is the concept of sustainable development, which aims to meet human needs worldwide and for future generations while keeping within the ecological capacity of the planet. Protest against unsustainable development is essentially about protecting mankind.
Moreover, development to meet community needs is very much on the agenda of environmental activists, as seen at last year's Pure Genius land occupation in Wandsworth, and in rural low-impact settlements such as Kingshill and Tinker's Bubble in Somerset. The real environmental authoritarianism lies with the Government, which has repeatedly used the planning system to block such attempts at people-based sustainability and enforced its own profit-based rationale for development.
The key challenge for the planning system is not so much the UK's household projections as the need fully to assimilate the green agenda. Too much of the current system perpetuates high-impact development, and merely determines the location of otherwise unsustainable land uses.
If this continues, we may look back more sympathetically on the "tree people", as rising seas lap the homes and gardens of Professor Hall's next generation of Milton Keyneses.