One consoling thing about stepping over the precipice into a new millennium is that history tells us the fate we fear most is never the one that overcomes us.A well-known example is the predicted increase in the production ofexcrement by transport animals that was made over 100 years ago.
This foresaw an alarming 90 million tonnes a year by 1900 and an intolerable 140 million tonnes a year by 1950.In the event draught animals managed only 80 million tonnes in 1900,while the problem had vanished by 1950.
The case ofthe vanishing mountain ofurban animal waste is often used as an example ofthe negation by technological progress ofa hypothetical threat.Alongside the contemporaneously predicted exhaustion ofthe coal reserves ofthe British Isles by 1945 it makes a valid point.Who in the nineteenth century would ever have imagined that the fate ofour coal reserves would become as unimportant as it seems today? And who could have foreseen that such small creatures as starlings, pigeons and dogs might themselves end up as an urban blight?
In Paris there are 200,000 resident dogs who deposit nearly 6,000 tonnes ofwaste on the streets ofthe city every year.
Most ofit is scooped up by the municipality's fleet ofvacuumequipped motor cycles,but this costs a not-negligible £6 million a year.Like diesel fumes this is an urban burden that was not even considered 100 years ago.
It is in the complicated nature ofwaste that it should be able to morph itself in and out ofthe red zone,whether animate or inanimate.Twenty years ago ring pulls from beverage cans were the villains, then they were banned and the cans themselves were redesigned so that there was no throwaway ring-pull.Next came aluminium beverage containers,which were thrown away in the shape oflitter that would last - said environmentalists - as long as the pyramids.They were wrong.A recycling industry sprang up that gave them too much value to be wasted,and substitute plastic containers took away half their market.
Next came used tyres,still the holy grail ofthe waste reclamation industry,innumerable,enormously strong,practically made ofpetroleum,but as hard to bury in landfill as they are to reprocess.A graph similar to that illustrating the projected growth ofanimal waste could be drawn for waste tyres,but the likelihood is that they will become more easily reusable or reprocessable before long.
Some 25 years ago,with the aid ofmy students at Rensselaer Polytechnic Institute in upstate New York,I built a house shell using locally available waste materials.It was demolished after a year or two but it is interesting to reflect on the changes in the composition and availability ofwaste that have taken place since then.The structural frame ofthe house was made from the cardboard cores ofgreat rolls ofnewsprint,tensioned into position with scrap steel strapping.
The ro ofwas covered with offcut 'tiles' ofneoprene rubber.The walls were ofsteel cans and bottles laid in mortar,insulated with cotton waste and protected from corrosion by a coating ofwaste sulphur from an oil refinery.
Today nearly everything is different.Newsprint cores are no longer a waste material;steel strapping has been largely supplanted by nylon;new production machinery has reduced the waste output ofneoprene so that the residue is now to small.Only the steel catering cans and bottles could be used in the same way now.
It would still be possible to do it,but anyone wanting to build a house using waste materials now ould have to do it in a completely different way.