Will English “destroy” all other languages?

Will English “destroy” all other languages?  The trend is certainly in that direction, and there is much hand-wringing and anguish in certain parts of academia (and other places, too). The language generally employed to describe this phenomenon is that other languages are being driven to extinction by the spread of English, and that predisposes people to think it's bad.  “Extinction” is bad, isn't it?  Always?

I'm not so sure, whether we're discussing critters, plants, or languages.  I'd have no problem with the extinction of mosquitoes (and my wife would be ecstatic!).  Similarly, if burdock were to disappear forever, I'd shed no tears.  Should I be anxious about the impending extinction of Naukan Yupik?

I'm not ready to out-and-out endorse the notion of making English the universal language of mankind.  I'm well aware that as a native English speaker, such an outcome would be oh-so-convenient for me.  As a veteran world traveler, though, I'm also very well aware of just how much friction the absence of a universal language for mankind introduces into any interaction between people who don't share a common language.  From locating a bathroom to ordering a meal to conducting some business, everything is harder if you and the person you're dealing with don't speak the same language.  Fluently.  Easily.  Natively.

I should note that I have a family reason for opposing the obliteration of non-English languages.  My sister has a business that's predicated on the idea of teaching English to people for whom it would be a second language.  The universal adoption of English would obliterate her business.  I've not talked with her about this, but somehow I doubt she'd be in favor of this outcome :)

I haven't made up my mind about this.  It's certainly true that language differences are an important part of the cultural differences that add a lot of interest to our world.  There are tradeoffs.  Most people talking about this topic tend toward overblown rhetoric mourning the disappearance of languages.  But is the disappearance of language X intrinsically “tragic”?  That's where I depart from the conventional line of thought, because I don't think so.  I'd like to hear what the adoption of English means for the welfare of the people in the affected population.  For example, if a young woman growing up in (say) eastern Siberia spoke English (natively) instead of the traditional local language spoken by 200 people – how much easier will it be for her to become a doctor?  A welder?  A programmer?  I know the answer – it will be enormously easier, for the simple reason that she can read and understand the texts that are widely available, not to mention what's on the Internet.  That's the tradeoff I'm interested in exploring: if the price of losing a language forever is X, what's the benefit?  And is it worth it?  I'd like to see a more sober weighing of the costs and benefits.  I'm no expert in this area, but in terms of what's visible to me, the benefits of a universal language outweigh the costs, and not by a small margin.

What do you think?