Dr Wall teaches economics at Goldsmiths College, University of London, and his most recent book "Babylon and Beyond" looks at alternatives to capitalism and corporate globalisation.
globalisation.
"Politics involves pressure, which is why I am shouting loudly for all those who care about the environment to support the Camp for Climate Action in Heathrow this summer.
"It runs from 14-21 August; so, instead of flying to Cape Cod, why not have a carbon neutral holiday at the end of the Piccadilly line?
"The fact that while spouting green rhetoric the Brown government are continuing to support Heathrow expansion and to widen roads suggests that we need deep-seated political change to get to an ecological society.
"All the pressure is on us as consumers but, if the structures of society make it difficult for us to live with respect for the biosphere and future generations, our minimal 'green' consumerist sacrifices are going to produce limited results.
"If I try to cycle down the hill to get into town, I frankly risk death; the buses, irregular at best, stop at around six o'clock.
"Happily, from a green point of view, I am too inept to pass a driving test.
"Green policymaking, rather than personal sacrifice, is the solution.
"We need cycle lanes, buses and better local services - we need joined up ecological policymaking.
"This government is keen on arms sales, big oil and air flights because of the power of cash-driven lobbyists.
"The expansion of Heathrow will not only accelerate climate change from the fastest growing source of greenhouse gas emissions, but will sweep away whole villages.
"If you go to the Museum of London, have a look at the displays on the Neolithic and Bronze Age: the Heathrow area was a bizarre ritual landscape in prehistoric times, with causeway camps, pits full of sacrificial bulls and a celtic temple.
"Now it is a Landscape of motels, McDonalds and motorways, equally bizarre (but rather less interesting).
"If one were to mention that a church or two will go under the tarmac, would the sceptics accuse the green campaigners, local residents and me of religious fanaticism?
"Direct action helped get women the vote.
"In the 1930s, the great Benny Rothman led a controversial trespass on Kinder Scout Moor in the Peak District to win rights for ramblers.
"He spoke on at least one Twyford Down rally in the 1990s to support Earth First fighting the roads programme.
"The protesters lost at Twyford but they stopped a much bigger roads programme.
"I am proud that the Green party fights elections and wins them sometimes, but I am just as proud to say that our manifesto lays down support for non-violent direct action as an appropriate way of bringing about social change.
"I am a novice - with just the odd caution, bind over and night in the cells - but I am always ready to learn from the dedicated, inspiring people of Camp for Climate Action.
"These direct actionists, who include such diverse groups as Plane Stupid, Platform and Earth First, are media savvy, politically sophisticated, grassroots democratic organisations pursuing root-and-branch reform of our carbon-intensive society.
"I am going to be listening to them and would urge all of you concerned with green issues to get stuck in with some camping for climate action." - Derek Wall.