Especially for those who were not around in the period 1970-1989 it is worth realising that communications were very different then.
For a start there was no internet, or even general access to a computer. There were no mobile phones. Printing and copying documents was a specialist activity. There were only 3 (until 1983) or eventually 4 television channels. Independent local radio did not exist, and the BBC had a limited offering of local stations. Satellite TV was a dream. National and local newspapers were a primary source of news and comment.
If you wanted to create a movement and communicate with supporters you faced very different challenges:
To create a document you started off with paper and pen. If you had access to a typewriter (and simple portable typewriters were relatively inexpensive - as a student from 1970 to 1976 my work was at first all handwritten, but by my third year I had acquired a secondhand portable typewriter, even so I was still handwriting essays in 1975) then you could type up your script. Electric typewriters had appeared in the office environment - but were driven by secretaries and typists (a specialist job that has more or less disappeared).
The only way to correct misteaks (or mistakes) when typing was either to strikethrough and type again, or if you were producing just a top copy to use white paint (Tippex) to overtype your mistake and then type the correction over the white paint.
When typing you could use carbon paper to to make one (or perhaps two, or even three if you hit the keys really hard) "carbon copies" of a document. Photocopiers had been invented in the 1940s and introduced into the office environment (primarily by Xerox) in the 1950s, but free access to a photocopier to duplicate your meeting notes or send out newsletters was not common.
More usual for low cost, low quality results was to type the script on special paper which produced a stencil that could be run through a duplicating machine (a Roneo). Roneo hand duplicators were simple enough for many small organisations to possess one (or at least to have access). You were still restricted to using just the typewriter font though.
By the early 70s the first "Instant Print" shops appeared in large towns offering bulk reproduction (photocopy) at a more or less reasonable price. Many newsletters, flyers and simple (black on white, or black on coloured paper) posters up to A4 size were produced this way. This allowed you to include not only typescript but also hand drawn graphics or different fonts and text sizes by using Letraset to create the original for copying.
Letraset and Instant Print shops transformed the communication landscape. Colour was still very limited, without using professional printers with associated costs and delays. Many posters that you can see in the document library were professionally printed. One alternative was to find an art student with access to a silk-screen press.
Home computers started to appear in the early 1980s - once they acquired floppy disk drives (rather than saving data and programmes on an audio cassette) these fairly rapidly became usable for domestic letter writing using a wordprocessor application and a relatively cheap dot-matrix printer.
Having got your precious words duplicated you then had to distribute them - by post. In 1971 a first class stamp cost 3p, by 1980 it was 10p and by 1990 it cost 22p for the cheapest 1st class stamp. That more or less tracked inflation over the period and continued to do so until the early 2000's. In recent years the cost of postage has grossly exceeded any monetary inflation uplift.
Whilst post remained the only option for communicating with members and supporters (aside from getting them to come to a meeting - which they could only know about if you posted them a notice, or if they were local enough for you to see them personally) it was the preferred method for getting information out.
If you wanted to have a conversation with someone at a distance then you had only land-line telephone as an option. Teleconferencing was not an option (except for high-end business applications) - it was strictly one-to-one. Telephones were provided by The Post Office - it could take months to get a new phone installed and you then had to rent the telephone instrument from the post office. BT was created in 1980 and separated from the Post Office in 1981 - and subsequently privatised and opened up to competition (although since it still owns the land-line network they have something of an advantage).
Given that today's internet, computer and mobile phone systems are all dependent on deeply unsustainable technologies - even if you could maintain the energy requirements of operating the internet without fossil fuels, the hardware used is all totally reliant on industrial processes that would be likely to take decades to replace with sustainable alternatives - it is very pertinent to be aware of what appropriate communication technologies might look like when it comes to operating within a declining industrial civilisation.
One of the reasons for studying Green History is to learn lessons that may be useful in the future. The green movement of the 1970s and 1980s was able to function effectively with the available technology. It may be that the ecology movement of the 2020's and 2030's will need to be using similar techniques.