Language is strange and incredible. We, as humans, somehow managed to create thousands of unique languages, with massive amounts of variance, somewhere along the line. It's something of an obstacle, nowadays, since globalization and global multilingualism don't pair that well, but it is nonetheless cool as hell. We should make a new one.
The first few steps don't sound that difficult; gather a few language experts from around the world, develop a new language that is easy to learn and simple, and then.... uh, I guess ask the UN to help with implementation?
Implementation is definitely the hard part, as evidenced by previous attempts to do this exact thing. Various attempts have been made, including Ido, Interlingua, and most notably Esperanto; the latter has speakers in the thousands to the millions, depending on who you ask. These languages were all developed, just not widely enough accepted to become the international lingua franca that they were envisioned as.
One major problem that all of these languages face is that that most, if not all of these 'constructed languages' are indo-european-ish in nature, with vocabulary, structure, alphabet, etc. based in the languages spoken by Europe and the Americas (I'm talking specifically about those that fall into the categories of Germanic, Italic, and to some extent Balto-slavic, Celtic, etc.). This is sort of a good thing, since it makes it easy for current speakers of those languages to learn these new ones, but it also means that people speaking languages that aren't in that family will have pretty similar difficulty learning them as a second languages as they would with, say, English - they'd needt to learn new pronunciations, alphabets, fundamental structures. The incredible diversity of world language ensures that there's no real way of making something 'easy to learn' for everyone.
Plus, people take pride in their language. I wouldn't consider myself someone who likes english, per se, but the idea of English being superseded by another language as the world's primary means of communication just seems wrong to me. I don't like it, but I couldn't tell you why - and I don't even have what one might consider 'deep cultural ties' to it. People just like their native language, I guess. That's another obstacle in making a new global language: people might not want to use it.
Anyway, hold onto this post for me, will you? I'm omw to go learn Esperanto.