It means planetary (Earth limited). It means all the world, and everything in it. The air, the water, the soil, the plants, the animals, the resources, the climate, everything. If global is everything, then global is nothing.
Why not international?
Because international is limited to people, preserving their cultural differences, based on national borders.. nationalism.. imagine no countries.. did Lennon and all his listeners, really know what he was suggesting?
How about intercultural?
I for one feel very uncomfortable with the word Global, just as uncomfortable as I was with the word, "World" when economists started using it in combination "World Trade Organisation". Since the Seattle riots, and similar inspired events of the time, they seem to be using "World" less these days, and using the word "Global" more.
Who is they? Well, start with the hegemony of the dominant English speaking nations for a start. Namely the USA and UK. They're not alone in their regular-as-clockwork, violent and hypocritical intrusions on other people's relative peace and civility. They continually project their colonial aspirations, like policing a world war on terror, and their internationally destabilizing concepts like the Global Financial Crisis, as though it was affecting everyone in the world, because it affects them.
I simply don't trust those with power in the world today, so why would I accept their faceless, all encompassing terminology like, Global, Globalism, Global Financial Crisis, Global Economy, Global Warming, and the agendas those words convey. It seems obvious to me, the true meaning of Global. One that does not respect national sovereignty and cultural difference, or even begin to appreciate different perspectives. One that freaks out at a hypothetical future climate scenario, and ignores the very same scenario here and now today, and yesterday, and the day before, while it drops very expensive ordnance all over Iraq, Afghanistan, Libya, and God knows how many other secret locations. One that is a certain, identifiable class of diplomats, walking out of a meeting of nations in the middle of a speech from one of the last remaining voices of descent, like spoiled, bullying teenage girls, or more clearly - violent minded corporations and governments who will resort to such bullying to pressure other nations to alienate their enemy, and (apparently) one who is developing an arsenal to attack us all... did I mention Global Spin?
Globalism is a concept that wants not just everyone, but everything, to submit to the hegemony of the word, and is one I simply will not use. I feel so strongly about this, I even catch myself stopping midway through any document that uses it, and re-evaluating it on those terms. I know most people use "Global" unthinkingly, but that unthinking use is precisely why I re-evaluate what they write. What else in there is un-thought-through. Suddenly I see all our parts in this, it's an easy word to replace if you try, and doing so may start to remove your latent acceptance of the violence in your culture, and your unquestioning propulsion of an idea you might actually disagree with.