If hemp is such an extraordinary plant, than why did it dissappear?
In our search for an explanation we have to think about the economical and political circumstances.
At the end of the 18th century the production process of cotton and the exploitation of the colonies through slavery evolved in such matter that cotton became a cheaper alternative for hemp.

Another industrial revolution, the invention of the steam engine, gave hemp the finishing stroke. The merchant ships were now driven by engines and no longer by sails. Rope was no longer an essential product and the rope industry, which was an important economical business, collapsed.

Hemp was still cultivated locally, but no longer for commercial purposes. Hemp lost ground in the advantage of cotton, rayon and synthetic fibres. Nylon was the first product made out of petrol. Traditional ropes were replaced by synthetic alternatives, but they were not stronger, only a little lighter, than hemp ropes.

That petrol isn’t renewable, was not an issue at that time. The only reason why hemp was replaced by synthetic alternatives was the lower cost of synthetic mass production.

In the 1930’s hemp was prohibited in an increasing amount of countries under the cloak of drug prevention. Marijuana, as you know by now, is gained out of another variety of the Cannabis Sativa. Hemp became a victim of the war on drugs at that time, however it has nothing to do with drugs! But the mixing up was very welcome for some other powerful industry lobbies.

In Belgium hemp was already prohibited in 1921, in the USA in 1937 followed by Canada in 1938. For now, Europe & Canada allows hemp cultivation again, but in the USA it’s still prohibited.
Only during WWII the hemp cultivation was shortly encouraged because of the lack on synthetic products and the problems with the supply of alternatives like abaca and jute.

If we look at the political and economical climate from the 1930’s, it’s obvious that industrial companies had an interest in prohibiting hemp.
Activists described in details how paper-, plastics-, cotton-, car- and oil companies felt threatened by the mechanical development of the hemp industry which could mean the revival of hemp.
Rudolf Diesel designed an engine that could run on vegetable oils (like hemp oil). And even Henry Ford designed an entire car made out of vegetable waste such as soy, cellulose and hemp fibres. This was of course bad news for the iron industry!

Underneath you can see a little movie about the Ford Hemp car:

A lot of ecological advantages of hemp were overshadowed by the less durable but economic more interesting alternatives. Developments in chemistry made it possible to find some techniques to process some natural products like rubber, sisal and hemp. For the western countries it meant more independence from oil producing countries.

It seemed that plastics, nylon and fossil fuels would be the future raw materials. But today it’s clear what the consequences are of a civilisation that runs on oil and other non-renewable raw materials (war, dependence,…). Luckily people finally start to realise this and the demand for renewable raw materials (bio-diesel) and plants (like hemp and flax) is rising.